Add Link Panel modifiers and legacy Ink Mixer presentation (#36)

src/main/java/net/dnorberg/rivencraft/block/entity/BookBinderBlockEntity.java

@@ -238,6 +238,11 @@ public final class BookBinderBlockEntity extends BlockEntity implements Containe
         ItemStack book = new ItemStack(ModItems.DESCRIPTIVE_BOOK.get());
         book.set(ModDataComponents.AGE_REFERENCE.get(), new AgeReference(pendingAgeId, title));
         book.set(ModDataComponents.BOOK_WRITING.get(), currentWriting());
+        if (items.get(LINK_PANEL).has(ModDataComponents.LINK_PROPERTIES.get())) {
+            var properties = items.get(LINK_PANEL).get(ModDataComponents.LINK_PROPERTIES.get())
+                    .forDescriptiveBook();
+            if (properties.flags() != 0) book.set(ModDataComponents.LINK_PROPERTIES.get(), properties);
+        }
         book.set(DataComponents.CUSTOM_NAME, Component.literal(title));
         return book;
     }

src/main/java/net/dnorberg/rivencraft/block/entity/InkMixerBlockEntity.java

@@ -1,8 +1,13 @@
 package net.dnorberg.rivencraft.block.entity;
 
+import java.util.Random;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.writing.InkVialExchange;
+import net.dnorberg.rivencraft.writing.InkModifierIngredients;
 import net.dnorberg.rivencraft.registry.ModBlockEntities;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.writing.WritingInkService;
 import net.minecraft.core.BlockPos;
@@ -18,7 +23,7 @@ import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
 
-/** Baseline Link Panel mixer. Modifier ingredients belong to the symbol/ink-effects milestone. */
+/** Server-owned Link Panel mixer with a persistent, Legacy-style additive mixture. */
 public final class InkMixerBlockEntity extends BlockEntity implements Container {
     public static final int INK = 0;
     public static final int PAPER = 1;
@@ -27,6 +32,12 @@ public final class InkMixerBlockEntity extends BlockEntity implements Container
 
     private NonNullList<ItemStack> items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
     private int inkRemaining;
+    private long nextModifierSeed = new Random().nextLong();
+    private final double[] modifierChances = new double[3];
+    private static final int[] FLAGS = {LinkProperties.DISARM,
+            LinkProperties.MAINTAIN_MOMENTUM, LinkProperties.INTRA_LINKING};
+    private static final String[] CHANCE_KEYS = {"DisarmChance", "MomentumChance", "IntraLinkingChance"};
+    private static final int[] OLD_CHANCE_INDEX = {0, 2, 3};
 
     public InkMixerBlockEntity(BlockPos pos, BlockState state) {
         super(ModBlockEntities.INK_MIXER.get(), pos, state);
@@ -34,6 +45,44 @@ public final class InkMixerBlockEntity extends BlockEntity implements Container
 
     public int inkRemaining() { return inkRemaining; }
 
+    public int modifierChancePermille(int index) {
+        return Math.clamp((int) Math.round(modifierChances[index] * 1000), 0, 1000);
+    }
+
+    /** Infuses a carried ingredient into the current ink pool; only the server calls this. */
+    public boolean addModifier(ItemStack carried, int amount) {
+        InkModifierIngredients.Ingredient ingredient = InkModifierIngredients.find(carried);
+        if (ingredient == null || inkRemaining == 0 || amount <= 0 || carried.getCount() < amount)
+            return false;
+        for (InkModifierIngredients.Effect effect : ingredient.effects())
+            for (int index = 0; index < FLAGS.length; index++)
+                if (FLAGS[index] == effect.flag())
+                    modifierChances[index] = 1.0 - (1.0 - modifierChances[index])
+                            * Math.pow(1.0 - effect.chance(), amount);
+        carried.shrink(amount);
+        setChanged();
+        return true;
+    }
+
+    public ItemStack previewLinkPanel() {
+        if (!canCreateLinkPanel()) return ItemStack.EMPTY;
+        ItemStack panel = PageItem.createLinkPanelPage();
+        LinkProperties properties = rollProperties(nextModifierSeed).properties();
+        if (properties.flags() != 0) panel.set(ModDataComponents.LINK_PROPERTIES.get(), properties);
+        return panel;
+    }
+
+    private record Roll(LinkProperties properties, long nextSeed) {}
+
+    private Roll rollProperties(long seed) {
+        Random random = new Random(seed);
+        int selected = 0;
+        for (int index = 0; index < FLAGS.length; index++)
+            if (modifierChances[index] > 0 && random.nextDouble() < modifierChances[index])
+                selected |= FLAGS[index];
+        return new Roll(new LinkProperties(selected), random.nextLong());
+    }
+
     @Override public int getContainerSize() { return SIZE; }
     @Override public boolean isEmpty() { return items.stream().allMatch(ItemStack::isEmpty); }
     @Override public ItemStack getItem(int slot) { return items.get(slot); }
@@ -92,6 +141,8 @@ public final class InkMixerBlockEntity extends BlockEntity implements Container
         inkRemaining -= cost;
         items.get(PAPER).shrink(1);
         if (items.get(PAPER).isEmpty()) items.set(PAPER, ItemStack.EMPTY);
+        nextModifierSeed = rollProperties(nextModifierSeed).nextSeed();
+        java.util.Arrays.fill(modifierChances, 0);
         setChanged();
         if (inkRemaining == 0) refillEmptyBasin();
         return true;
@@ -104,6 +155,7 @@ public final class InkMixerBlockEntity extends BlockEntity implements Container
     @Override public void clearContent() {
         items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
         inkRemaining = 0;
+        java.util.Arrays.fill(modifierChances, 0);
         setChanged();
     }
     @Override protected void loadAdditional(CompoundTag tag, HolderLookup.Provider registries) {
@@ -111,11 +163,20 @@ public final class InkMixerBlockEntity extends BlockEntity implements Container
         items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
         ContainerHelper.loadAllItems(tag, items, registries);
         inkRemaining = Math.clamp(tag.getInt("InkRemaining"), 0, InkVialItem.CAPACITY);
+        if (tag.contains("NextModifierSeed")) nextModifierSeed = tag.getLong("NextModifierSeed");
+        for (int index = 0; index < modifierChances.length; index++) {
+            double chance = tag.contains(CHANCE_KEYS[index]) ? tag.getDouble(CHANCE_KEYS[index])
+                    : tag.getDouble("ModifierChance" + OLD_CHANCE_INDEX[index]);
+            modifierChances[index] = Math.clamp(chance, 0.0, 1.0);
+        }
         refillEmptyBasin();
     }
     @Override protected void saveAdditional(CompoundTag tag, HolderLookup.Provider registries) {
         super.saveAdditional(tag, registries);
         ContainerHelper.saveAllItems(tag, items, registries);
         tag.putInt("InkRemaining", inkRemaining);
+        tag.putLong("NextModifierSeed", nextModifierSeed);
+        for (int index = 0; index < modifierChances.length; index++)
+            tag.putDouble(CHANCE_KEYS[index], modifierChances[index]);
     }
 }

src/main/java/net/dnorberg/rivencraft/block/entity/WritingDeskBlockEntity.java

@@ -1,8 +1,12 @@
 package net.dnorberg.rivencraft.block.entity;
 
 import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.writing.InkVialExchange;
 import net.dnorberg.rivencraft.writing.WritingInkService;
+import net.dnorberg.rivencraft.writing.PageContent;
+import net.dnorberg.rivencraft.writing.NotebookContents;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModBlockEntities;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.minecraft.core.BlockPos;
@@ -83,7 +87,11 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
                         worldPosition.getZ() + 0.5) <= 64.0;
     }
     @Override public boolean canPlaceItem(int slot, ItemStack stack) {
-        if (slot < COLLECTIONS) return stack.is(ModItems.NOTEBOOK.get()) || stack.is(ModItems.PAGE.get());
+        if (slot < COLLECTIONS) return stack.is(ModItems.NOTEBOOK.get())
+                && stack.getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY)
+                        .pages().stream().noneMatch(page -> PageItem.content(page).kind() == PageContent.Kind.LINK_PANEL)
+                || stack.is(ModItems.PAGE.get())
+                && PageItem.content(stack).kind() != PageContent.Kind.LINK_PANEL;
         return switch (slot) {
             case INK -> stack.is(ModItems.INK_VIAL.get());
             case RETURN -> false;

src/main/java/net/dnorberg/rivencraft/book/LinkProperties.java

@@ -0,0 +1,60 @@
+package net.dnorberg.rivencraft.book;
+
+import com.mojang.serialization.Codec;
+import io.netty.buffer.ByteBuf;
+import java.util.List;
+import net.minecraft.ChatFormatting;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.chat.Component;
+
+/** Flags written into a Link Panel and carried by books assembled from it. */
+public record LinkProperties(int flags) {
+    public static final int DISARM = 1;
+    /** Retained only to read pre-0.4.7.1 test books; no longer generated or applied. */
+    public static final int GENERATE_PLATFORM = 2;
+    public static final int MAINTAIN_MOMENTUM = 4;
+    public static final int INTRA_LINKING = 8;
+    private static final int ALL_FLAGS = DISARM | GENERATE_PLATFORM | MAINTAIN_MOMENTUM | INTRA_LINKING;
+    public static final LinkProperties NONE = new LinkProperties(0);
+    public static final Codec<LinkProperties> CODEC = Codec.intRange(0, ALL_FLAGS).xmap(
+            LinkProperties::new, LinkProperties::flags);
+    public static final StreamCodec<ByteBuf, LinkProperties> STREAM_CODEC = StreamCodec.of(
+            (buffer, value) -> ByteBufCodecs.VAR_INT.encode(buffer, value.flags),
+            buffer -> new LinkProperties(ByteBufCodecs.VAR_INT.decode(buffer)));
+
+    public LinkProperties {
+        if ((flags & ~ALL_FLAGS) != 0 || flags < 0) {
+            throw new IllegalArgumentException("Unknown Link Panel flags: " + flags);
+        }
+    }
+
+    public boolean has(int flag) {
+        return (flags & flag) != 0;
+    }
+
+    /** Intra Linking only governs Linking Books; a Descriptive Book treats that panel as ordinary. */
+    public LinkProperties forDescriptiveBook() {
+        return new LinkProperties(flags & ~INTRA_LINKING);
+    }
+
+    public void appendTooltip(List<Component> lines) {
+        if (has(DISARM)) lines.add(propertyName("disarm"));
+        if (has(MAINTAIN_MOMENTUM)) lines.add(propertyName("maintain_momentum"));
+        if (has(INTRA_LINKING)) lines.add(propertyName("intra_linking"));
+    }
+
+    private static Component propertyName(String name) {
+        return Component.translatable("item.rivencraft.link_property." + name)
+                .withStyle(ChatFormatting.DARK_PURPLE);
+    }
+
+    public static Component name(int flag) {
+        return switch (flag) {
+            case DISARM -> propertyName("disarm");
+            case MAINTAIN_MOMENTUM -> propertyName("maintain_momentum");
+            case INTRA_LINKING -> propertyName("intra_linking");
+            default -> throw new IllegalArgumentException("Unknown link property flag: " + flag);
+        };
+    }
+}

src/main/java/net/dnorberg/rivencraft/book/LinkingService.java

@@ -25,7 +25,11 @@ public final class LinkingService {
     }
 
     public static LinkResult travel(ServerPlayer player, LinkTarget target) {
-        return travel(player, target, false);
+        return travel(player, target, LinkProperties.NONE);
+    }
+
+    public static LinkResult travel(ServerPlayer player, LinkTarget target, LinkProperties properties) {
+        return travel(player, target, false, properties);
     }
 
     public static Optional<Vec3> resolveDestination(ServerLevel level, BlockPos origin, boolean ageArrival) {
@@ -36,27 +40,36 @@ public final class LinkingService {
 
     /** Travels to an Age-style destination, which must have solid footing. */
     public static LinkResult travelWithFooting(ServerPlayer player, LinkTarget target) {
+        return travelWithFooting(player, target, LinkProperties.NONE);
+    }
+
+    public static LinkResult travelWithFooting(ServerPlayer player, LinkTarget target, LinkProperties properties) {
         ServerLevel destinationLevel = player.getServer().getLevel(target.location().dimension());
         if (destinationLevel == null) {
             return LinkResult.MISSING_DIMENSION;
         }
-
         Optional<Vec3> destination = resolveDestination(destinationLevel, target.location().pos(), true);
         if (destination.isEmpty()) {
             return LinkResult.NO_SAFE_DESTINATION;
         }
 
         Vec3 position = destination.get();
+        Vec3 momentum = player.getDeltaMovement();
+        if (properties.has(LinkProperties.DISARM)) dropInventoryAtSource(player);
         teleport(player, destinationLevel, position, target);
+        if (properties.has(LinkProperties.MAINTAIN_MOMENTUM)) player.setDeltaMovement(momentum);
         player.resetFallDistance();
         return LinkResult.SUCCESS;
     }
 
-    private static LinkResult travel(ServerPlayer player, LinkTarget target, boolean requiresFooting) {
+    private static LinkResult travel(ServerPlayer player, LinkTarget target, boolean requiresFooting,
+                                     LinkProperties properties) {
         ServerLevel destinationLevel = player.getServer().getLevel(target.location().dimension());
         if (destinationLevel == null) {
             return LinkResult.MISSING_DIMENSION;
         }
+        if (destinationLevel == player.level() && !properties.has(LinkProperties.INTRA_LINKING))
+            return LinkResult.INTRA_LINKING_REQUIRED;
 
         Optional<Vec3> destination = resolveDestination(destinationLevel, target.location().pos(), requiresFooting);
         if (destination.isEmpty()) {
@@ -64,11 +77,26 @@ public final class LinkingService {
         }
 
         Vec3 position = destination.get();
+        Vec3 momentum = player.getDeltaMovement();
+        if (properties.has(LinkProperties.DISARM)) dropInventoryAtSource(player);
         teleport(player, destinationLevel, position, target);
+        if (properties.has(LinkProperties.MAINTAIN_MOMENTUM)) player.setDeltaMovement(momentum);
         player.resetFallDistance();
         return LinkResult.SUCCESS;
     }
 
+    /** Drop each inventory stack as an item entity at the departure point. */
+    private static void dropInventoryAtSource(ServerPlayer player) {
+        var inventory = player.getInventory();
+        for (int slot = 0; slot < inventory.getContainerSize(); slot++) {
+            var stack = inventory.getItem(slot);
+            if (stack.isEmpty()) continue;
+            inventory.setItem(slot, net.minecraft.world.item.ItemStack.EMPTY);
+            player.drop(stack, false);
+        }
+        player.containerMenu.broadcastChanges();
+    }
+
     private static void teleport(
             ServerPlayer player,
             ServerLevel destinationLevel,
@@ -166,6 +194,7 @@ public final class LinkingService {
     public enum LinkResult {
         SUCCESS,
         MISSING_DIMENSION,
+        INTRA_LINKING_REQUIRED,
         NO_SAFE_DESTINATION
     }
 }

src/main/java/net/dnorberg/rivencraft/client/screen/InkMixerScreen.java

@@ -8,11 +8,20 @@ import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.inventory.ClickType;
 
 /** Legacy Ink Mixer atlas with a server-synced, sixteen-use basin. */
 public final class InkMixerScreen extends AbstractContainerScreen<InkMixerMenu> {
     private static final ResourceLocation BACKGROUND = ResourceLocation.fromNamespaceAndPath(
             Rivencraft.MOD_ID, "textures/gui/ink_mixer_legacy.png");
+    private static final int BASIN_X = 88;
+    private static final int BASIN_Y = 49;
+    private static final int BASIN_RADIUS = 30;
+    // Legacy's registered property colors: Disarm red, Momentum blue, Intra green.
+    private static final int[] PROPERTY_COLORS = {0xFFE84848, 0xFF5555FF, 0xFF55EF55};
+    private final int[] lastChances = new int[3];
+    private boolean basinClickPendingRelease;
+    private long lastAdditionTime;
 
     public InkMixerScreen(InkMixerMenu menu, Inventory inventory, Component title) {
         super(menu, inventory, title);
@@ -26,16 +35,14 @@ public final class InkMixerScreen extends AbstractContainerScreen<InkMixerMenu>
         renderBg(graphics, partialTick, mouseX, mouseY);
     }
     @Override protected void renderBg(GuiGraphics graphics, float partialTick, int mouseX, int mouseY) {
-        graphics.blit(BACKGROUND, leftPos, topPos, 0, 0, imageWidth, imageHeight, 256, 256);
-        int centerX = leftPos + 88;
-        int centerY = topPos + 49;
-        int fillTop = centerY + 26 - Math.round(menu.inkRemaining() / (float) InkVialItem.CAPACITY * 52);
+        // Legacy draws this inset behind the transparent center of the main atlas.
+        graphics.blit(BACKGROUND, leftPos + 54, topPos + 16, 179, 16, 66, 65, 256, 256);
         if (menu.inkRemaining() > 0) {
-            for (int y = Math.max(centerY - 26, fillTop); y <= centerY + 26; y++) {
-                int halfWidth = (int) Math.sqrt(26 * 26 - (y - centerY) * (y - centerY));
-                graphics.fill(centerX - halfWidth, y, centerX + halfWidth + 1, y + 1, 0xFF241228);
-            }
+            // Ink is a full dark basin in Legacy, rather than a vertical meter.
+            graphics.fill(leftPos + 54, topPos + 16, leftPos + 120, topPos + 81, 0xFF101014);
+            renderPropertyGlyph(graphics);
         }
+        graphics.blit(BACKGROUND, leftPos, topPos, 0, 0, imageWidth, imageHeight, 256, 256);
     }
     @Override protected void renderLabels(GuiGraphics graphics, int mouseX, int mouseY) {
         graphics.drawString(font, playerInventoryTitle, inventoryLabelX, inventoryLabelY, 0x404040, false);
@@ -43,10 +50,112 @@ public final class InkMixerScreen extends AbstractContainerScreen<InkMixerMenu>
     @Override public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
         super.render(graphics, mouseX, mouseY, partialTick);
         renderTooltip(graphics, mouseX, mouseY);
-        int x = mouseX - (leftPos + 88);
-        int y = mouseY - (topPos + 49);
-        if (x * x + y * y <= 26 * 26)
-            graphics.renderTooltip(font, Component.translatable("screen.rivencraft.ink_mixer.ink",
-                    menu.inkRemaining(), InkVialItem.CAPACITY), mouseX, mouseY);
+        if (overBasin(mouseX, mouseY)) {
+            var lines = new java.util.ArrayList<Component>();
+            lines.add(Component.translatable("screen.rivencraft.ink_mixer.ink",
+                    menu.inkRemaining(), InkVialItem.CAPACITY));
+            lines.add(Component.translatable("screen.rivencraft.ink_mixer.additive_hint"));
+            for (int index = 0; index < 3; index++) {
+                int chance = menu.modifierChancePermille(index);
+                if (chance > 0) lines.add(Component.translatable("screen.rivencraft.ink_mixer.chance",
+                        switch (index) {
+                            case 0 -> Component.translatable("item.rivencraft.link_property.disarm");
+                            case 1 -> Component.translatable("item.rivencraft.link_property.maintain_momentum");
+                            default -> Component.translatable("item.rivencraft.link_property.intra_linking");
+                        }, chance / 10.0));
+            }
+            graphics.renderTooltip(font, lines, java.util.Optional.empty(), mouseX, mouseY);
+        }
+    }
+
+    @Override public boolean mouseClicked(double mouseX, double mouseY, int button) {
+        if ((button == 0 || button == 1) && overBasin(mouseX, mouseY)
+                && !menu.getCarried().isEmpty()) {
+            slotClicked(menu.getSlot(InkMixerMenu.MODIFIER), InkMixerMenu.MODIFIER, button, ClickType.PICKUP);
+            basinClickPendingRelease = true;
+            return true;
+        }
+        return super.mouseClicked(mouseX, mouseY, button);
+    }
+
+    @Override public boolean mouseReleased(double mouseX, double mouseY, int button) {
+        if (basinClickPendingRelease) {
+            basinClickPendingRelease = false;
+            return true;
+        }
+        return super.mouseReleased(mouseX, mouseY, button);
+    }
+
+    private boolean overBasin(double mouseX, double mouseY) {
+        double x = mouseX - leftPos - BASIN_X;
+        double y = mouseY - topPos - BASIN_Y;
+        return x * x + y * y < BASIN_RADIUS * BASIN_RADIUS;
+    }
+
+    /** A GUI-scale projection of Legacy's colored, rotating D'ni ink effect. */
+    private void renderPropertyGlyph(GuiGraphics graphics) {
+        long now = System.currentTimeMillis();
+        int[] active = new int[3];
+        int count = 0;
+        int strongest = 0;
+        for (int index = 0; index < lastChances.length; index++) {
+            int chance = menu.modifierChancePermille(index);
+            if (chance > lastChances[index]) lastAdditionTime = now;
+            lastChances[index] = chance;
+            if (chance > 0) {
+                active[count++] = index;
+                strongest = Math.max(strongest, chance);
+            }
+        }
+        if (count == 0) {
+            lastAdditionTime = 0;
+            return;
+        }
+
+        double cycle = now / 1800.0;
+        int first = active[(int) cycle % count];
+        int second = active[((int) cycle + 1) % count];
+        double blend = (1.0 - Math.cos((cycle % 1.0) * Math.PI)) / 2.0;
+        int rgb = blendRgb(PROPERTY_COLORS[first], PROPERTY_COLORS[second], blend);
+        double pulse = Math.max(0.0, 1.0 - (now - lastAdditionTime) / 700.0);
+        int alpha = Math.clamp((int) (70 + strongest * 0.14 + pulse * 45), 0, 255);
+        int color = alpha << 24 | rgb;
+        int centerX = leftPos + BASIN_X;
+        int centerY = topPos + BASIN_Y;
+        double turn = now / 1200.0;
+
+        for (int spoke = 0; spoke < 4; spoke++) {
+            for (int step = 0; step <= 30; step++) {
+                double progress = step / 30.0;
+                double angle = turn + spoke * Math.PI / 2.0 + progress * 0.9;
+                double radius = 3.0 + progress * (15.0 + pulse * 3.0);
+                plot(graphics, centerX + Math.cos(angle) * radius,
+                        centerY + Math.sin(angle) * radius, color);
+            }
+        }
+        for (int step = 0; step < 96; step++) {
+            double angle = step * Math.PI / 48.0 + turn * 0.3;
+            plot(graphics, centerX + Math.cos(angle) * 19.0,
+                    centerY + Math.sin(angle) * 19.0, color);
+            if (strongest >= 990 && step % 2 == 0) {
+                plot(graphics, centerX + Math.cos(angle) * 23.0,
+                        centerY + Math.sin(angle) * 23.0, color);
+            }
+        }
+    }
+
+    private static int blendRgb(int first, int second, double amount) {
+        int red = (int) (((first >> 16) & 0xFF) * (1.0 - amount)
+                + ((second >> 16) & 0xFF) * amount);
+        int green = (int) (((first >> 8) & 0xFF) * (1.0 - amount)
+                + ((second >> 8) & 0xFF) * amount);
+        int blue = (int) ((first & 0xFF) * (1.0 - amount) + (second & 0xFF) * amount);
+        return red << 16 | green << 8 | blue;
+    }
+
+    private static void plot(GuiGraphics graphics, double x, double y, int color) {
+        int pixelX = (int) Math.round(x);
+        int pixelY = (int) Math.round(y);
+        graphics.fill(pixelX, pixelY, pixelX + 1, pixelY + 1, color);
     }
 }

src/main/java/net/dnorberg/rivencraft/client/screen/NotebookScreen.java

@@ -6,6 +6,7 @@ import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.client.SymbolPageTextures;
 import net.dnorberg.rivencraft.menu.NotebookMenu;
 import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.PageContent;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.EditBox;
@@ -115,7 +116,8 @@ public final class NotebookScreen extends AbstractContainerScreen<NotebookMenu>
         if (index >= 0 && (button == 0 || button == 1)) {
             ItemStack page = menu.getSlot(index).getItem();
             if ((!page.isEmpty() && !matchesSearch(page))
-                    || (page.isEmpty() && !menu.getCarried().is(ModItems.PAGE.get()))) {
+                    || (page.isEmpty() && (!menu.getCarried().is(ModItems.PAGE.get())
+                            || PageItem.content(menu.getCarried()).kind() == PageContent.Kind.LINK_PANEL))) {
                 return true;
             }
             setFocused(null);

src/main/java/net/dnorberg/rivencraft/client/screen/WritingDeskScreen.java

@@ -7,6 +7,7 @@ import java.util.Comparator;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.client.SymbolPageTextures;
 import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.writing.PageContent;
 import net.dnorberg.rivencraft.menu.WritingDeskMenu;
 import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
@@ -329,7 +330,9 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
         int surfaceY = (int) Math.floor(mouseY - topPos - 20);
         if ((button == 0 || button == 1) && !menu.getCarried().isEmpty()
                 && surfaceX >= 0 && surfaceX < 155 && surfaceY >= 0 && surfaceY < 164) {
-            if (menu.getCarried().is(ModItems.PAGE.get()) && surfaceX % 31 < 30 && surfaceY % 41 < 40) {
+            if (menu.getCarried().is(ModItems.PAGE.get())
+                    && PageItem.content(menu.getCarried()).kind() != PageContent.Kind.LINK_PANEL
+                    && surfaceX % 31 < 30 && surfaceY % 41 < 40) {
                 int index = (surfaceY / 41 + scrollRows) * 5 + surfaceX / 31;
                 List<DisplayPage> entries = filteredPages();
                 // Only displayed positions are addressable. Filtering never turns

src/main/java/net/dnorberg/rivencraft/compat/jei/RivencraftJeiPlugin.java

@@ -23,11 +23,16 @@ import mezz.jei.api.ingredients.subtypes.UidContext;
 import mezz.jei.api.runtime.IJeiRuntime;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.book.LinkProperties;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
+import net.dnorberg.rivencraft.writing.InkModifierIngredients;
 import net.dnorberg.rivencraft.writing.PageContent;
+import net.dnorberg.rivencraft.writing.SymbolReference;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.network.chat.Component;
+import net.minecraft.network.chat.MutableComponent;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
@@ -52,7 +57,8 @@ public final class RivencraftJeiPlugin implements IModPlugin {
                     PageContent content = PageItem.content(stack);
                     return switch (content.kind()) {
                         case BLANK -> "blank";
-                        case LINK_PANEL -> "link_panel";
+                        case LINK_PANEL -> "link_panel:" + stack.getOrDefault(
+                                ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE).flags();
                         case SYMBOL -> "symbol:" + content.symbol().orElseThrow().id();
                         case UNRESOLVED_SYMBOL -> "unresolved:" + content.symbol().orElseThrow().id();
                     };
@@ -103,17 +109,23 @@ public final class RivencraftJeiPlugin implements IModPlugin {
     @Override
     public void registerRecipes(IRecipeRegistration registration) {
         ItemStack panel = PageItem.createLinkPanelPage();
+        ItemStack symbolPage = PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "terrain/standard")));
         registration.addRecipes(WRITING, List.of(
                 new WritingGuide(List.of(new ItemStack(Items.PAPER), new ItemStack(ModItems.INK_VIAL.get())),
                         panel, "jei.rivencraft.writing.link_panel_hand"),
-                new WritingGuide(List.of(panel, new ItemStack(Items.PAPER), new ItemStack(ModItems.INK_VIAL.get())),
-                        panel, "jei.rivencraft.writing.copy"),
+                new WritingGuide(List.of(symbolPage, new ItemStack(Items.PAPER), new ItemStack(ModItems.INK_VIAL.get())),
+                        symbolPage, "jei.rivencraft.writing.copy"),
                 new WritingGuide(List.of(new ItemStack(Items.LEATHER), panel),
                         new ItemStack(ModItems.DESCRIPTIVE_BOOK.get()), "jei.rivencraft.writing.bind"),
                 new WritingGuide(List.of(panel, new ItemStack(Items.LEATHER)),
                         new ItemStack(ModItems.LINKING_BOOK.get()), "jei.rivencraft.writing.linking_book")
         ));
-        registration.addRecipes(INK_MIXER, List.of(new InkMixerGuide(panel)));
+        List<InkMixerGuide> mixerGuides = new ArrayList<>();
+        mixerGuides.add(new InkMixerGuide(panel, null));
+        InkModifierIngredients.builtIn().forEach(ingredient ->
+                mixerGuides.add(new InkMixerGuide(panel, ingredient)));
+        registration.addRecipes(INK_MIXER, mixerGuides);
     }
 
     @Override
@@ -124,7 +136,7 @@ public final class RivencraftJeiPlugin implements IModPlugin {
     }
 
     private record WritingGuide(List<ItemStack> inputs, ItemStack output, String instructionKey) {}
-    private record InkMixerGuide(ItemStack panel) {}
+    private record InkMixerGuide(ItemStack panel, InkModifierIngredients.Ingredient additive) {}
 
     private static final class InkMixerCategory extends AbstractRecipeCategory<InkMixerGuide> {
         InkMixerCategory(IGuiHelper guiHelper) {
@@ -138,6 +150,9 @@ public final class RivencraftJeiPlugin implements IModPlugin {
             builder.addInputSlot(2, 3).setStandardSlotBackground().addItemStack(new ItemStack(Items.PAPER));
             builder.addInputSlot(23, 3).setStandardSlotBackground()
                     .addItemStack(new ItemStack(ModItems.INK_VIAL.get()));
+            if (recipe.additive() != null)
+                builder.addInputSlot(44, 3).setStandardSlotBackground()
+                        .addItemStack(recipe.additive().item());
             builder.addOutputSlot(112, 3).setOutputSlotBackground().addItemStack(recipe.panel());
             builder.addOutputSlot(112, 46).setStandardSlotBackground()
                     .addItemStack(new ItemStack(Items.GLASS_BOTTLE));
@@ -146,8 +161,20 @@ public final class RivencraftJeiPlugin implements IModPlugin {
         @Override
         public void draw(InkMixerGuide recipe, IRecipeSlotsView slots, GuiGraphics graphics,
                          double mouseX, double mouseY) {
-            graphics.drawWordWrap(Minecraft.getInstance().font,
-                    Component.translatable("jei.rivencraft.ink_mixer.usage"), 2, 27, 104, 0x404040);
+            Component instructions = recipe.additive() == null
+                    ? Component.translatable("jei.rivencraft.ink_mixer.usage")
+                    : additiveInstructions(recipe.additive());
+            graphics.drawWordWrap(Minecraft.getInstance().font, instructions, 2, 27, 104, 0x404040);
+        }
+
+        private static Component additiveInstructions(InkModifierIngredients.Ingredient additive) {
+            MutableComponent effects = Component.empty();
+            for (InkModifierIngredients.Effect effect : additive.effects()) {
+                if (!effects.getSiblings().isEmpty()) effects.append(", ");
+                effects.append(Component.translatable("jei.rivencraft.ink_mixer.effect",
+                        LinkProperties.name(effect.flag()), Math.round(effect.chance() * 100)));
+            }
+            return Component.translatable("jei.rivencraft.ink_mixer.additive", effects);
         }
     }
 

src/main/java/net/dnorberg/rivencraft/gametest/BookBinderGameTests.java

@@ -133,7 +133,14 @@ public final class BookBinderGameTests {
         helper.assertFalse(binder.consumeAssembly(), "Failure must consume nothing");
         helper.assertTrue(binder.getItem(BookBinderBlockEntity.COVER).is(Items.LEATHER),
                 "Rejected assembly must preserve cover");
-        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        ItemStack flavoredPanel = PageItem.createLinkPanelPage();
+        flavoredPanel.set(ModDataComponents.LINK_PROPERTIES.get(),
+                new net.dnorberg.rivencraft.book.LinkProperties(
+                        net.dnorberg.rivencraft.book.LinkProperties.DISARM
+                                | net.dnorberg.rivencraft.book.LinkProperties.MAINTAIN_MOMENTUM
+                                | net.dnorberg.rivencraft.book.LinkProperties.INTRA_LINKING));
+        var expectedProperties = flavoredPanel.get(ModDataComponents.LINK_PROPERTIES.get()).forDescriptiveBook();
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, flavoredPanel);
         var player = helper.makeMockServerPlayerInLevel();
         player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
                 binder.getBlockPos().getZ() + 0.5);
@@ -143,6 +150,9 @@ public final class BookBinderGameTests {
         menu.clicked(BookBinderMenu.RESULT, 0, ClickType.PICKUP, player);
         ItemStack book = menu.getCarried();
         helper.assertTrue(book.is(ModItems.DESCRIPTIVE_BOOK.get()), "Result must be a Descriptive Book");
+        helper.assertValueEqual(book.get(ModDataComponents.LINK_PROPERTIES.get()),
+                expectedProperties,
+                "Binder must retain Disarm and Momentum but omit Intra Linking");
         AgeReference age = book.get(ModDataComponents.AGE_REFERENCE.get());
         helper.assertTrue(age != null, "Assembled book must already be a written Age book");
         OrderedWriting writing = book.get(ModDataComponents.BOOK_WRITING.get());

src/main/java/net/dnorberg/rivencraft/gametest/CoreGameTests.java

@@ -102,6 +102,11 @@ public final class CoreGameTests {
         InkMixerGameTests.linkPanelRequiresTakingOutputAndPersistsInk(helper);
     }
 
+    @GameTest(template = "empty")
+    public static void mixerModifierTransaction(GameTestHelper helper) {
+        InkMixerGameTests.modifierClickPersistsPreviewAndConsumesOnce(helper);
+    }
+
     @GameTest(template = "empty")
     public static void linkingBookRecipe(GameTestHelper helper) {
         LinkingBookRecipeGameTests.legacyRecipeRequiresExactlyLeatherAndLinkPanel(helper);

src/main/java/net/dnorberg/rivencraft/gametest/InkMixerGameTests.java

@@ -28,6 +28,69 @@ public final class InkMixerGameTests {
         return (InkMixerBlockEntity) helper.getLevel().getBlockEntity(pos);
     }
 
+    public static void modifierClickPersistsPreviewAndConsumesOnce(GameTestHelper helper) {
+        InkMixerBlockEntity mixer = place(helper);
+        mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
+        mixer.setItem(InkMixerBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(mixer.getBlockPos().getX() + 0.5, mixer.getBlockPos().getY() + 0.5,
+                mixer.getBlockPos().getZ() + 0.5);
+        InkMixerMenu menu = new InkMixerMenu(1, player.getInventory(), mixer);
+        menu.setCarried(new ItemStack(Items.GUNPOWDER, 2));
+        menu.clicked(InkMixerMenu.MODIFIER, 1, ClickType.PICKUP, player);
+        helper.assertValueEqual(menu.getCarried().getCount(), 1, "Right click must consume one additive");
+        helper.assertValueEqual(mixer.modifierChancePermille(0), 200,
+                "Gunpowder must add Legacy's 20% Disarm chance");
+        menu.setCarried(new ItemStack(Items.STONE));
+        menu.clicked(InkMixerMenu.MODIFIER, 0, ClickType.PICKUP, player);
+        helper.assertValueEqual(menu.getCarried().getCount(), 1, "Invalid additive must remain carried");
+        helper.assertValueEqual(mixer.modifierChancePermille(0), 200,
+                "Invalid additive must not change the mixture");
+        ItemStack preview = mixer.previewLinkPanel();
+        var saved = mixer.saveWithoutMetadata(helper.getLevel().registryAccess());
+        var restored = new InkMixerBlockEntity(mixer.getBlockPos(), ModBlocks.INK_MIXER.get().defaultBlockState());
+        restored.loadWithComponents(saved, helper.getLevel().registryAccess());
+        helper.assertTrue(ItemStack.matches(preview, restored.previewLinkPanel()),
+                "Saving must retain the mixture and deterministic next-panel preview");
+        menu.setCarried(ItemStack.EMPTY);
+        menu.clicked(InkMixerMenu.RESULT, 0, ClickType.PICKUP, player);
+        helper.assertTrue(menu.getCarried().is(ModItems.PAGE.get()), "Taking result must give a panel");
+        helper.assertValueEqual(mixer.modifierChancePermille(0), 0,
+                "Mixture must be spent only when a panel is taken");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 1,
+                "Taking the panel must consume exactly one paper");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void enderPearlsRaiseBothPropertiesIndependentlyAndResetOnOutput(GameTestHelper helper) {
+        InkMixerBlockEntity mixer = place(helper);
+        mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
+        mixer.setItem(InkMixerBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        ItemStack pearls = new ItemStack(Items.ENDER_PEARL, 20);
+        helper.assertTrue(mixer.addModifier(pearls, 20), "Ender Pearls must infuse the basin");
+        helper.assertTrue(pearls.isEmpty(), "Twenty pearls must be consumed exactly once");
+        helper.assertValueEqual(mixer.modifierChancePermille(0), 961,
+                "Disarm must approach 100% independently");
+        helper.assertValueEqual(mixer.modifierChancePermille(2), 961,
+                "Intra Linking must approach 100% independently");
+        helper.assertValueEqual(mixer.modifierChancePermille(1), 0,
+                "Ender Pearls must not add Momentum");
+
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(mixer.getBlockPos().getX() + 0.5, mixer.getBlockPos().getY() + 0.5,
+                mixer.getBlockPos().getZ() + 0.5);
+        InkMixerMenu menu = new InkMixerMenu(1, player.getInventory(), mixer);
+        menu.clicked(InkMixerMenu.RESULT, 0, ClickType.PICKUP, player);
+        helper.assertTrue(menu.getCarried().is(ModItems.PAGE.get()), "Taking output must yield one panel");
+        for (int index = 0; index < 3; index++)
+            helper.assertValueEqual(mixer.modifierChancePermille(index), 0,
+                    "Every modifier chance must reset when output is taken");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 1,
+                "Taking output must consume one paper");
+        helper.succeed();
+    }
+
     public static void linkPanelRequiresTakingOutputAndPersistsInk(GameTestHelper helper) {
         InkMixerBlockEntity mixer = place(helper);
         mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));

src/main/java/net/dnorberg/rivencraft/gametest/LinkingBookRecipeGameTests.java

@@ -2,6 +2,7 @@ package net.dnorberg.rivencraft.gametest;
 
 import java.util.List;
 import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
@@ -48,6 +49,8 @@ public final class LinkingBookRecipeGameTests {
     public static void outputIsUnwrittenAndRegisteredRecipeLoads(GameTestHelper helper) {
         ItemStack panel = PageItem.createLinkPanelPage();
         panel.set(DataComponents.CUSTOM_NAME, Component.literal("Home Panel"));
+        panel.set(ModDataComponents.LINK_PROPERTIES.get(),
+                new LinkProperties(LinkProperties.INTRA_LINKING | LinkProperties.MAINTAIN_MOMENTUM));
         CraftingInput input = CraftingInput.of(2, 1, List.of(panel, new ItemStack(Items.LEATHER)));
         var holder = helper.getLevel().getRecipeManager()
                 .getRecipeFor(RecipeType.CRAFTING, input, helper.getLevel()).orElseThrow();
@@ -60,6 +63,14 @@ public final class LinkingBookRecipeGameTests {
         helper.assertFalse(result.has(ModDataComponents.PAGE_CONTENT.get()), "Page identity must not leak onto the book");
         helper.assertValueEqual(result.get(DataComponents.CUSTOM_NAME), Component.literal("Home Panel"),
                 "The panel's custom name must survive crafting");
+        helper.assertValueEqual(result.get(ModDataComponents.LINK_PROPERTIES.get()),
+                panel.get(ModDataComponents.LINK_PROPERTIES.get()),
+                "The panel's link properties must survive crafting");
+        ItemStack restored = ItemStack.parseOptional(helper.getLevel().registryAccess(),
+                (net.minecraft.nbt.CompoundTag) result.saveOptional(helper.getLevel().registryAccess()));
+        helper.assertValueEqual(restored.get(ModDataComponents.LINK_PROPERTIES.get()),
+                panel.get(ModDataComponents.LINK_PROPERTIES.get()),
+                "The crafted book's link properties must persist through save/load");
         helper.succeed();
     }
 }

src/main/java/net/dnorberg/rivencraft/gametest/LinkingGameTests.java

@@ -11,6 +11,7 @@ import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
 import net.dnorberg.rivencraft.book.AgeRuntimeProfile;
 import net.dnorberg.rivencraft.book.AgeRuntimeProfiles;
 import net.dnorberg.rivencraft.book.LinkTarget;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.book.LinkingService;
 import net.dnorberg.rivencraft.book.AgeVisitSavedData;
 import net.dnorberg.rivencraft.book.AgeTraits;
@@ -578,7 +579,8 @@ public final class LinkingGameTests {
         ServerPlayer player = helper.makeMockServerPlayerInLevel();
         LinkTarget target = new LinkTarget(GlobalPos.of(helper.getLevel().dimension(), destination), 90.0F, 15.0F);
 
-        LinkingService.LinkResult result = LinkingService.travel(player, target);
+        LinkingService.LinkResult result = LinkingService.travel(player, target,
+                new LinkProperties(LinkProperties.INTRA_LINKING));
 
         helper.assertValueEqual(result, LinkingService.LinkResult.SUCCESS,
                 "A Linking Book must accept leaf blocks even without a floor");
@@ -603,7 +605,8 @@ public final class LinkingGameTests {
         ServerPlayer player = helper.makeMockServerPlayerInLevel();
         LinkTarget target = new LinkTarget(GlobalPos.of(helper.getLevel().dimension(), absoluteOrigin), 0.0F, 0.0F);
 
-        helper.assertValueEqual(LinkingService.travelWithFooting(player, target), LinkingService.LinkResult.SUCCESS,
+        helper.assertValueEqual(LinkingService.travelWithFooting(player, target,
+                        new LinkProperties(LinkProperties.INTRA_LINKING)), LinkingService.LinkResult.SUCCESS,
                 "Descriptive Book travel must find an alternate grounded arrival");
         BlockPos landing = player.blockPosition();
         helper.assertTrue(helper.getLevel().getBlockState(landing.below()).isFaceSturdy(
@@ -624,8 +627,10 @@ public final class LinkingGameTests {
         ServerPlayer player = helper.makeMockServerPlayerInLevel();
         LinkTarget target = new LinkTarget(GlobalPos.of(helper.getLevel().dimension(), absoluteOrigin), 0.0F, 0.0F);
 
-        helper.assertValueEqual(LinkingService.travel(player, target), LinkingService.LinkResult.NO_SAFE_DESTINATION,
+        helper.assertValueEqual(LinkingService.travel(player, target,
+                        new LinkProperties(LinkProperties.INTRA_LINKING)), LinkingService.LinkResult.NO_SAFE_DESTINATION,
                 "Linking must fail rather than placing a player inside a blocked destination");
         helper.succeed();
     }
+
 }

src/main/java/net/dnorberg/rivencraft/gametest/WritingDataGameTests.java

@@ -287,6 +287,8 @@ public final class WritingDataGameTests {
 
         helper.assertFalse(menu.getSlot(0).mayPlace(new ItemStack(Items.DIRT)),
                 "Notebook slots must reject non-Page items");
+        helper.assertFalse(menu.getSlot(0).mayPlace(PageItem.createLinkPanelPage()),
+                "Notebook slots must reject Link Panels");
         menu.getSlot(0).set(first);
         menu.getSlot(1).set(second);
         helper.assertTrue(menu.clickMenuButton(player, NotebookMenu.MOVE_NEXT_BASE),

src/main/java/net/dnorberg/rivencraft/gametest/WritingDeskGameTests.java

@@ -97,7 +97,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        ItemStack source = PageItem.createLinkPanelPage();
+        ItemStack source = terrainPage();
         desk.setItem(0, source.copy());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
@@ -180,7 +180,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(0, terrainPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
         desk.setItem(WritingDeskBlockEntity.RETURN, new ItemStack(Items.GLASS_BOTTLE, 64));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
@@ -210,7 +210,7 @@ public final class WritingDeskGameTests {
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
         ItemStack notebook = new ItemStack(ModItems.NOTEBOOK.get());
         notebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(),
-                new NotebookContents(List.of(ItemStack.EMPTY, PageItem.createLinkPanelPage())));
+                new NotebookContents(List.of(ItemStack.EMPTY, terrainPage())));
         desk.setItem(0, notebook);
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
@@ -232,7 +232,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(0, terrainPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         var first = helper.makeMockServerPlayerInLevel();
@@ -258,7 +258,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(0, terrainPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         var player = helper.makeMockServerPlayerInLevel();
@@ -319,7 +319,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(0, terrainPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         var player = helper.makeMockServerPlayerInLevel();
@@ -446,7 +446,7 @@ public final class WritingDeskGameTests {
         helper.assertTrue(menu.clickMenuButton(player, 87), "Tab 88 must be selectable without page-ID collisions");
         helper.assertValueEqual(desk.activeCollection(), 87, "Tab 88 must become active");
         helper.assertFalse(menu.clickMenuButton(player, 88), "Tab 89 must not exist");
-        desk.setItem(87, PageItem.createLinkPanelPage());
+        desk.setItem(87, terrainPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.ALL_PAGE_BUTTON_BASE + 87 * NotebookContents.MAX_PAGES),
@@ -502,7 +502,7 @@ public final class WritingDeskGameTests {
         var player = helper.makeMockServerPlayerInLevel();
         player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
         var menu = new WritingDeskMenu(1, player.getInventory(), desk);
-        ItemStack held = PageItem.createLinkPanelPage().copyWithCount(3);
+        ItemStack held = terrainPage().copyWithCount(3);
         ItemStack expectedPage = held.copyWithCount(1);
         player.getInventory().setItem(9, held);
         menu.clicked(WritingDeskMenu.COPY_RESULT + 1, 0, ClickType.PICKUP, player);
@@ -520,7 +520,7 @@ public final class WritingDeskGameTests {
         helper.assertValueEqual(menu.pageCapacity(87), NotebookContents.MAX_PAGES, "Notebook tab must expose normal notebook capacity");
         helper.assertValueEqual(menu.pageCapacity(0), 0, "Empty tab has no page storage");
         helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE), "Empty tab must require a collection first");
-        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(0, terrainPage());
         helper.assertValueEqual(menu.pageCapacity(0), 1, "Loose page tab must expose exactly one position");
         helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE), "Loose page must not be replaced");
         helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE + 1), "Loose page tab must not grow extra positions");
@@ -543,14 +543,13 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        ItemStack linkPanel = PageItem.createLinkPanelPage();
-        ItemStack terrain = PageItem.createSymbolPage(new SymbolReference(
-                ResourceLocation.parse("rivencraft:terrain/standard")));
+        ItemStack movingPage = terrainPage();
+        ItemStack terrain = terrainPage();
         ItemStack firstBook = new ItemStack(ModItems.NOTEBOOK.get());
-        firstBook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(linkPanel, terrain)));
+        firstBook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(movingPage, terrain)));
         desk.setItem(0, firstBook);
         desk.setItem(1, new ItemStack(ModItems.NOTEBOOK.get()));
-        desk.setItem(2, PageItem.createLinkPanelPage());
+        desk.setItem(2, terrainPage());
         var player = helper.makeMockServerPlayerInLevel();
         player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
         var menu = new WritingDeskMenu(1, player.getInventory(), desk);
@@ -558,18 +557,18 @@ public final class WritingDeskGameTests {
         helper.assertTrue(menu.clickMenuButton(player, moveToEmpty), "Drag must move to a distant empty notebook position");
         var pages = desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
         helper.assertTrue(pages.get(0).isEmpty(), "Moving must clear the source position");
-        helper.assertTrue(ItemStack.matches(pages.get(26), linkPanel), "Moving must preserve page components");
+        helper.assertTrue(ItemStack.matches(pages.get(26), movingPage), "Moving must preserve page components");
         helper.assertValueEqual(desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pageCount(), 2,
                 "Moving must preserve total page count");
         helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 26, 0, 1)),
                 "Drag onto an occupied position must swap pages");
         pages = desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
-        helper.assertTrue(ItemStack.matches(pages.get(1), linkPanel) && ItemStack.matches(pages.get(26), terrain),
+        helper.assertTrue(ItemStack.matches(pages.get(1), movingPage) && ItemStack.matches(pages.get(26), terrain),
                 "Swap must preserve both pages");
         helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 1, 1, 5)),
                 "Drag into another notebook must work");
         var otherPages = desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
-        helper.assertTrue(ItemStack.matches(otherPages.get(5), linkPanel)
+        helper.assertTrue(ItemStack.matches(otherPages.get(5), movingPage)
                 && desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(1).isEmpty(),
                 "Cross notebook move must have one destination and no old source");
         helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 1, 1, 6)),
@@ -584,7 +583,7 @@ public final class WritingDeskGameTests {
         menu.setCarried(new ItemStack(Items.DIAMOND));
         helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(1, 5, 1, 6)),
                 "Held inventory items must not be moved by a panel drag");
-        helper.assertTrue(ItemStack.matches(desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(5), linkPanel),
+        helper.assertTrue(ItemStack.matches(desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(5), movingPage),
                 "Rejected drags must leave notebook data intact");
         helper.succeed();
     }
@@ -594,7 +593,7 @@ public final class WritingDeskGameTests {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
         helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
         var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
-        ItemStack page = PageItem.createLinkPanelPage();
+        ItemStack page = terrainPage();
         ItemStack source = new ItemStack(ModItems.NOTEBOOK.get());
         source.set(ModDataComponents.NOTEBOOK_CONTENTS.get(),
                 new NotebookContents(List.of(page, page, page, page, page, page)));
@@ -643,4 +642,47 @@ public final class WritingDeskGameTests {
                 "Extracting a loose page must empty its tab and return the same item");
         helper.succeed();
     }
+
+    @GameTest(template = "empty")
+    public static void linkPanelsCannotBeStoredOrCopiedButOldPanelsCanBeRecovered(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        ItemStack panel = PageItem.createLinkPanelPage();
+        ItemStack oldNotebook = new ItemStack(ModItems.NOTEBOOK.get());
+        oldNotebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(panel)));
+        helper.assertFalse(desk.canPlaceItem(0, panel), "Desk tab must reject a Link Panel");
+        helper.assertFalse(desk.canPlaceItem(0, oldNotebook),
+                "Desk tab must reject a Notebook containing an old Link Panel");
+
+        // A preexisting desk is loaded without discarding its contents.
+        desk.setItem(0, panel.copy());
+        desk.setItem(1, new ItemStack(ModItems.NOTEBOOK.get()));
+        desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        var menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        menu.broadcastChanges();
+        helper.assertTrue(menu.getSlot(WritingDeskMenu.COPY_RESULT).getItem().isEmpty(),
+                "Existing Link Panels must not produce a Desk copy");
+        helper.assertTrue(menu.quickMoveStack(player, WritingDeskMenu.COPY_RESULT).isEmpty(),
+                "Shift-click must not bypass the Link Panel copy rule");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 0, 1, 0)),
+                "An old Link Panel must not move into a Notebook");
+        menu.setCarried(panel.copy());
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE
+                + NotebookContents.MAX_PAGES), "A carried Link Panel must not enter a Notebook");
+        menu.setCarried(ItemStack.EMPTY);
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 0, -1)),
+                "A stored legacy Link Panel must remain recoverable to the cursor");
+        helper.assertTrue(ItemStack.matches(menu.getCarried(), panel),
+                "Recovery must preserve the original Link Panel");
+        helper.succeed();
+    }
+
+    private static ItemStack terrainPage() {
+        return PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.parse("rivencraft:terrain/standard")));
+    }
 }

src/main/java/net/dnorberg/rivencraft/item/DescriptiveBookItem.java

@@ -4,6 +4,7 @@ import java.util.List;
 import net.dnorberg.rivencraft.book.AgeReference;
 import net.dnorberg.rivencraft.book.AgeVisitSavedData;
 import net.dnorberg.rivencraft.book.LinkTarget;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.book.LinkingService;
 import net.dnorberg.rivencraft.book.AgeDimensionService;
 import net.dnorberg.rivencraft.config.RivencraftConfig;
@@ -54,7 +55,9 @@ public final class DescriptiveBookItem extends Item {
 
         ServerLevel sourceLevel = player.serverLevel();
         var sourcePosition = player.blockPosition();
-        LinkingService.LinkResult result = LinkingService.travelWithFooting(player, ageTarget);
+        LinkProperties properties = stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE)
+                .forDescriptiveBook();
+        LinkingService.LinkResult result = LinkingService.travelWithFooting(player, ageTarget, properties);
         if (result != LinkingService.LinkResult.SUCCESS) {
             player.displayClientMessage(Component.translatable("message.rivencraft.descriptive_book.unsafe"), true);
             return false;
@@ -109,5 +112,7 @@ public final class DescriptiveBookItem extends Item {
                 ? Component.translatable("item.rivencraft.descriptive_book.unwritten")
                 : Component.translatable("item.rivencraft.descriptive_book.age", age.name());
         tooltipComponents.add(status.withStyle(ChatFormatting.GRAY));
+        stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE)
+                .forDescriptiveBook().appendTooltip(tooltipComponents);
     }
 }

src/main/java/net/dnorberg/rivencraft/item/LinkingBookItem.java

@@ -4,6 +4,7 @@ import java.util.List;
 import net.dnorberg.rivencraft.book.LinkTarget;
 import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
 import net.dnorberg.rivencraft.book.LinkingService;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModSounds;
 import net.minecraft.ChatFormatting;
@@ -49,7 +50,8 @@ public final class LinkingBookItem extends Item {
 
         Level sourceLevel = player.level();
         BlockPos sourcePosition = player.blockPosition();
-        LinkingService.LinkResult result = LinkingService.travel(player, target);
+        LinkProperties properties = stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE);
+        LinkingService.LinkResult result = LinkingService.travel(player, target, properties);
         if (result == LinkingService.LinkResult.SUCCESS) {
             sourceLevel.playSound(null, sourcePosition, ModSounds.LINK.get(), SoundSource.PLAYERS,
                     0.8F, sourceLevel.random.nextFloat() * 0.2F + 0.9F);
@@ -65,9 +67,11 @@ public final class LinkingBookItem extends Item {
             return InteractionResultHolder.success(stack);
         }
 
-        String errorKey = result == LinkingService.LinkResult.MISSING_DIMENSION
-                ? "message.rivencraft.linking_book.missing_dimension"
-                : "message.rivencraft.linking_book.unsafe";
+        String errorKey = switch (result) {
+            case MISSING_DIMENSION -> "message.rivencraft.linking_book.missing_dimension";
+            case INTRA_LINKING_REQUIRED -> "message.rivencraft.linking_book.intra_required";
+            default -> "message.rivencraft.linking_book.unsafe";
+        };
         player.displayClientMessage(Component.translatable(errorKey), true);
         return InteractionResultHolder.fail(stack);
     }
@@ -85,9 +89,11 @@ public final class LinkingBookItem extends Item {
             TooltipFlag tooltipFlag
     ) {
         LinkTarget target = stack.get(ModDataComponents.LINK_TARGET.get());
+        LinkProperties properties = stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE);
         if (target == null) {
             tooltipComponents.add(Component.translatable("item.rivencraft.linking_book.unbound")
                     .withStyle(ChatFormatting.GRAY));
+            properties.appendTooltip(tooltipComponents);
             return;
         }
 
@@ -101,6 +107,7 @@ public final class LinkingBookItem extends Item {
                         position.getZ()
                 )
                 .withStyle(ChatFormatting.GRAY));
+        properties.appendTooltip(tooltipComponents);
     }
 
     public static String destinationName(ServerLevel level) {

src/main/java/net/dnorberg/rivencraft/item/PageItem.java

@@ -11,6 +11,7 @@ import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.Set;
 import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.writing.PageContent;
@@ -223,6 +224,8 @@ public final class PageItem extends Item {
         if (content.kind() == PageContent.Kind.LINK_PANEL) {
             tooltipComponents.add(Component.translatable("item.rivencraft.page.link_panel.description")
                     .withStyle(ChatFormatting.GRAY));
+            stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE)
+                    .appendTooltip(tooltipComponents);
             return;
         }
         SymbolReference reference = content.symbol().orElseThrow();

src/main/java/net/dnorberg/rivencraft/menu/InkMixerMenu.java

@@ -10,6 +10,7 @@ import net.minecraft.world.SimpleContainer;
 import net.minecraft.world.entity.player.Inventory;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.ClickType;
 import net.minecraft.world.inventory.DataSlot;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
@@ -17,13 +18,15 @@ import net.minecraft.world.item.Items;
 
 /** Server-owned virtual output; taking it spends paper and the configured ink cost once. */
 public final class InkMixerMenu extends AbstractContainerMenu {
-    public static final int RESULT = InkMixerBlockEntity.SIZE;
+    public static final int MODIFIER = InkMixerBlockEntity.SIZE;
+    public static final int RESULT = MODIFIER + 1;
     private static final int PLAYER_START = RESULT + 1;
     private final InkMixerBlockEntity mixer;
     private final Container inputs;
     private final SimpleContainer result = new SimpleContainer(1);
     private final boolean clientSide;
     private int inkRemaining;
+    private final int[] modifierChances = new int[3];
 
     public InkMixerMenu(int id, Inventory inventory, RegistryFriendlyByteBuf data) {
         this(id, inventory, inventory.player.level().getBlockEntity(data.readBlockPos())
@@ -39,9 +42,19 @@ public final class InkMixerMenu extends AbstractContainerMenu {
             @Override public int get() { return clientSide ? inkRemaining : mixer.inkRemaining(); }
             @Override public void set(int value) { inkRemaining = value; }
         });
+        for (int index = 0; index < modifierChances.length; index++) {
+            final int chanceIndex = index;
+            addDataSlot(new DataSlot() {
+                @Override public int get() {
+                    return clientSide ? modifierChances[chanceIndex] : mixer.modifierChancePermille(chanceIndex);
+                }
+                @Override public void set(int value) { modifierChances[chanceIndex] = value; }
+            });
+        }
         addSlot(new MixerSlot(InkMixerBlockEntity.INK, 8, 27));
         addSlot(new MixerSlot(InkMixerBlockEntity.PAPER, 8, 48));
         addSlot(new MixerSlot(InkMixerBlockEntity.BOTTLES, 152, 27));
+        addSlot(new ModifierSlot(79, 40));
         addSlot(new ResultSlot(152, 48));
         for (int row = 0; row < 3; row++)
             for (int column = 0; column < 9; column++)
@@ -52,6 +65,24 @@ public final class InkMixerMenu extends AbstractContainerMenu {
     }
 
     public int inkRemaining() { return inkRemaining; }
+    public int modifierChancePermille(int index) { return modifierChances[index]; }
+
+    @Override public void clicked(int slotId, int button, ClickType clickType, Player player) {
+        if (slotId == MODIFIER) {
+            if (!clientSide && stillValid(player) && clickType == ClickType.PICKUP
+                    && (button == 0 || button == 1)) {
+                ItemStack carried = getCarried();
+                int amount = button == 1 ? 1 : carried.getCount();
+                if (mixer.addModifier(carried, amount)) {
+                    setCarried(carried);
+                    refreshResult();
+                    broadcastChanges();
+                }
+            }
+            return;
+        }
+        super.clicked(slotId, button, clickType, player);
+    }
 
     @Override public boolean stillValid(Player player) {
         return mixer != null && mixer.stillValid(player);
@@ -64,8 +95,7 @@ public final class InkMixerMenu extends AbstractContainerMenu {
 
     private void refreshResult() {
         if (clientSide) return;
-        ItemStack preview = mixer != null && mixer.canCreateLinkPanel()
-                ? PageItem.createLinkPanelPage() : ItemStack.EMPTY;
+        ItemStack preview = mixer == null ? ItemStack.EMPTY : mixer.previewLinkPanel();
         if (!ItemStack.matches(result.getItem(0), preview)) result.setItem(0, preview);
     }
 
@@ -87,7 +117,7 @@ public final class InkMixerMenu extends AbstractContainerMenu {
         ItemStack source = slot.getItem();
         ItemStack original = source.copy();
         boolean moved;
-        if (index < RESULT) moved = moveItemStackTo(source, PLAYER_START, slots.size(), true);
+        if (index < MODIFIER) moved = moveItemStackTo(source, PLAYER_START, slots.size(), true);
         else if (source.is(ModItems.INK_VIAL.get()))
             moved = moveItemStackTo(source, InkMixerBlockEntity.INK, InkMixerBlockEntity.INK + 1, false);
         else if (source.is(Items.PAPER))
@@ -105,6 +135,12 @@ public final class InkMixerMenu extends AbstractContainerMenu {
         @Override public boolean mayPlace(ItemStack stack) { return inputs.canPlaceItem(getContainerSlot(), stack); }
     }
 
+    private static final class ModifierSlot extends Slot {
+        ModifierSlot(int x, int y) { super(new SimpleContainer(1), 0, x, y); }
+        @Override public boolean mayPlace(ItemStack stack) { return false; }
+        @Override public boolean mayPickup(Player player) { return false; }
+    }
+
     private final class ResultSlot extends Slot {
         ResultSlot(int x, int y) { super(result, 0, x, y); }
         @Override public boolean mayPlace(ItemStack stack) { return false; }

src/main/java/net/dnorberg/rivencraft/menu/NotebookMenu.java

@@ -5,6 +5,8 @@ import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.registry.ModMenus;
 import net.dnorberg.rivencraft.writing.NotebookContents;
+import net.dnorberg.rivencraft.writing.PageContent;
+import net.dnorberg.rivencraft.item.PageItem;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.world.Container;
@@ -82,6 +84,7 @@ public final class NotebookMenu extends AbstractContainerMenu {
             }
         } else {
             if (!source.is(ModItems.PAGE.get())
+                    || PageItem.content(source).kind() == PageContent.Kind.LINK_PANEL
                     || !moveItemStackTo(source, 0, PLAYER_INVENTORY_START, false)) {
                 return ItemStack.EMPTY;
             }
@@ -135,7 +138,10 @@ public final class NotebookMenu extends AbstractContainerMenu {
             super(container, slot, x, y);
         }
 
-        @Override public boolean mayPlace(ItemStack stack) { return stack.is(ModItems.PAGE.get()); }
+        @Override public boolean mayPlace(ItemStack stack) {
+            return stack.is(ModItems.PAGE.get())
+                    && PageItem.content(stack).kind() != PageContent.Kind.LINK_PANEL;
+        }
         @Override public int getMaxStackSize() { return 1; }
     }
 

src/main/java/net/dnorberg/rivencraft/menu/WritingDeskMenu.java

@@ -180,7 +180,7 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
     private boolean placeCarriedPage(int collectionIndex, int pageIndex) {
         // Resolve the actual storage position on the server, never a filtered list index.
         ItemStack carried = getCarried();
-        if (clientSide || !carried.is(ModItems.PAGE.get())) return false;
+        if (clientSide || !storablePage(carried)) return false;
         ItemStack collection = desk.getItem(collectionIndex);
         if (collection.is(ModItems.NOTEBOOK.get())) {
             var pages = new java.util.ArrayList<>(collection.getOrDefault(
@@ -215,12 +215,14 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         if (sourceNotebook && (sourcePage >= sourcePages.size() || sourcePages.get(sourcePage).isEmpty())) return false;
         ItemStack moving = sourceNotebook ? sourcePages.get(sourcePage) : sourceBook;
         if (moving.getCount() != 1) return false;
+        if (!storablePage(moving)) return false;
         if (!targetNotebook && targetBook.getCount() != 1) return false;
         var targetPages = targetNotebook ? sourceCollection == targetCollection ? sourcePages
                 : new java.util.ArrayList<>(targetBook.getOrDefault(
                         ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages()) : null;
         if (targetNotebook) while (targetPages.size() <= targetPage) targetPages.add(ItemStack.EMPTY);
         ItemStack displaced = targetNotebook ? targetPages.get(targetPage) : targetBook;
+        if (!displaced.isEmpty() && !storablePage(displaced)) return false;
         if (targetNotebook) targetPages.set(targetPage, moving);
         if (sourceNotebook) {
             sourcePages.set(sourcePage, displaced);
@@ -256,6 +258,7 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
             setCarried(moving);
         } else {
             if (targetSlot >= WritingDeskBlockEntity.COLLECTIONS && targetSlot < PLAYER_START) return false;
+            if (targetSlot < WritingDeskBlockEntity.COLLECTIONS && !storablePage(moving)) return false;
             Slot target = slots.get(targetSlot);
             if (!target.isActive() || !target.mayPlace(moving)) return false;
             ItemStack current = target.getItem();
@@ -340,10 +343,15 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         if (moving.is(Items.PAPER))
             return moveItemStackTo(moving, WritingDeskBlockEntity.PAPER,
                     WritingDeskBlockEntity.PAPER + 1, false);
-        if (moving.is(ModItems.PAGE.get())) return moveItemStackTo(moving, firstVisibleTab, firstVisibleTab + VISIBLE_TABS, false);
+        if (storablePage(moving)) return moveItemStackTo(moving, firstVisibleTab, firstVisibleTab + VISIBLE_TABS, false);
         return false;
     }
 
+    private static boolean storablePage(ItemStack stack) {
+        return stack.is(ModItems.PAGE.get())
+                && PageItem.content(stack).kind() != PageContent.Kind.LINK_PANEL;
+    }
+
     private ItemStack selectedSource() {
         if (selectedSymbol != null) {
             SymbolReference reference = new SymbolReference(selectedSymbol);
@@ -375,6 +383,7 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         ItemStack source = selectedSource();
         return blockEntity != null && source.is(ModItems.PAGE.get())
                 && PageItem.content(source).kind() != PageContent.Kind.BLANK
+                && PageItem.content(source).kind() != PageContent.Kind.LINK_PANEL
                 && PageItem.isUsableWriting(source) && blockEntity.canConsumeCopyMaterials();
     }
 

src/main/java/net/dnorberg/rivencraft/registry/ModDataComponents.java

@@ -2,6 +2,7 @@ package net.dnorberg.rivencraft.registry;
 
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.book.LinkTarget;
+import net.dnorberg.rivencraft.book.LinkProperties;
 import net.dnorberg.rivencraft.book.AgeReference;
 import net.dnorberg.rivencraft.writing.PageContent;
 import net.dnorberg.rivencraft.writing.NotebookContents;
@@ -26,6 +27,12 @@ public final class ModDataComponents {
                     .networkSynchronized(LinkTarget.STREAM_CODEC)
                     .cacheEncoding()
                     .build());
+    public static final DeferredHolder<DataComponentType<?>, DataComponentType<LinkProperties>> LINK_PROPERTIES =
+            DATA_COMPONENTS.register("link_properties", () -> DataComponentType.<LinkProperties>builder()
+                    .persistent(LinkProperties.CODEC)
+                    .networkSynchronized(LinkProperties.STREAM_CODEC)
+                    .cacheEncoding()
+                    .build());
     public static final DeferredHolder<DataComponentType<?>, DataComponentType<AgeReference>> AGE_REFERENCE =
             DATA_COMPONENTS.register("age_reference", () -> DataComponentType.<AgeReference>builder()
                     .persistent(AgeReference.CODEC)

src/main/java/net/dnorberg/rivencraft/writing/InkModifierIngredients.java

@@ -0,0 +1,33 @@
+package net.dnorberg.rivencraft.writing;
+
+import java.util.List;
+import net.dnorberg.rivencraft.book.LinkProperties;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+/** Built-in Legacy ink additives. Optional mod dusts will be mapped through tags separately. */
+public final class InkModifierIngredients {
+    public record Effect(int flag, double chance) {}
+    public record Ingredient(ItemStack item, List<Effect> effects) {}
+
+    private static final List<Ingredient> BUILT_IN = List.of(
+            new Ingredient(new ItemStack(Items.GUNPOWDER), List.of(new Effect(LinkProperties.DISARM, 0.20))),
+            new Ingredient(new ItemStack(Items.MUSHROOM_STEW), List.of(new Effect(LinkProperties.DISARM, 0.05))),
+            new Ingredient(new ItemStack(Items.EXPERIENCE_BOTTLE), List.of(new Effect(LinkProperties.INTRA_LINKING, 0.15))),
+            new Ingredient(new ItemStack(Items.ENDER_PEARL), List.of(
+                    new Effect(LinkProperties.INTRA_LINKING, 0.15),
+                    new Effect(LinkProperties.DISARM, 0.15))),
+            new Ingredient(new ItemStack(Items.FEATHER), List.of(new Effect(LinkProperties.MAINTAIN_MOMENTUM, 0.15))),
+            new Ingredient(new ItemStack(Items.FIRE_CHARGE), List.of(new Effect(LinkProperties.DISARM, 0.25)))
+    );
+
+    private InkModifierIngredients() {}
+
+    public static List<Ingredient> builtIn() {
+        return BUILT_IN;
+    }
+
+    public static Ingredient find(ItemStack stack) {
+        return BUILT_IN.stream().filter(ingredient -> stack.is(ingredient.item().getItem())).findFirst().orElse(null);
+    }
+}

src/main/java/net/dnorberg/rivencraft/writing/LinkingBookRecipe.java

@@ -1,6 +1,7 @@
 package net.dnorberg.rivencraft.writing;
 
 import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.registry.ModRecipeSerializers;
 import net.minecraft.core.HolderLookup;
@@ -50,11 +51,13 @@ public final class LinkingBookRecipe extends CustomRecipe {
         ItemStack panel = findPanel(input);
         if (panel.isEmpty()) return ItemStack.EMPTY;
         ItemStack book = new ItemStack(ModItems.LINKING_BOOK.get());
-        // Legacy copied the panel's data. Only its custom name is meaningful to a
-        // 1.21.1 Linking Book today; page-only components must not reach the book.
+        // Copy book-relevant panel data, never the Page identity component.
         if (panel.has(DataComponents.CUSTOM_NAME)) {
             book.set(DataComponents.CUSTOM_NAME, panel.get(DataComponents.CUSTOM_NAME));
         }
+        if (panel.has(ModDataComponents.LINK_PROPERTIES.get())) {
+            book.set(ModDataComponents.LINK_PROPERTIES.get(), panel.get(ModDataComponents.LINK_PROPERTIES.get()));
+        }
         return book;
     }
 

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -10,7 +10,10 @@
   "item.rivencraft.page.blank": "Blank Page",
   "item.rivencraft.page.blank.description": "Ready for writing at a Writing Desk.",
   "item.rivencraft.page.link_panel": "Link Panel Page",
-  "item.rivencraft.page.link_panel.description": "The baseline panel required to assemble a Descriptive Book.",
+  "item.rivencraft.page.link_panel.description": "A Link Panel for assembling books.",
+  "item.rivencraft.link_property.disarm": "Disarm",
+  "item.rivencraft.link_property.maintain_momentum": "Maintain Momentum",
+  "item.rivencraft.link_property.intra_linking": "Intra Linking",
   "item.rivencraft.page.unresolved": "Unresolved Symbol Page",
   "item.rivencraft.notebook": "Notebook",
   "item.rivencraft.notebook.pages": "Pages: %s/%s",
@@ -23,6 +26,8 @@
   "block.rivencraft.ink_mixer": "Ink Mixer",
   "container.rivencraft.ink_mixer": "Ink Mixer",
   "screen.rivencraft.ink_mixer.ink": "Ink: %s/%s",
+  "screen.rivencraft.ink_mixer.additive_hint": "Click the basin with an additive; right-click adds one.",
+  "screen.rivencraft.ink_mixer.chance": "%s: %s%%",
   "screen.rivencraft.book_binder.title": "Book title",
   "screen.rivencraft.book_binder.title_hint": "Name the book",
   "screen.rivencraft.book_binder.missing_panel": "Link Panel required as the first page",
@@ -67,6 +72,7 @@
   "message.rivencraft.linking_book.linked": "Linked",
   "message.rivencraft.linking_book.missing_dimension": "That dimension is unavailable",
   "message.rivencraft.linking_book.unsafe": "No safe destination was found near the link",
+  "message.rivencraft.linking_book.intra_required": "This book needs an Intra Linking panel for same-dimension travel",
   "message.rivencraft.descriptive_book.unwritten": "This Descriptive Book is unwritten",
   "message.rivencraft.descriptive_book.created": "Created Age: %s",
   "message.rivencraft.descriptive_book.unavailable": "That Age is unavailable",
@@ -243,6 +249,8 @@
   "jei.rivencraft.writing.link_panel_hand": "Hold paper and an Ink Vial in opposite hands; use the vial to make a Link Panel.",
   "jei.rivencraft.ink_mixer": "Ink Mixer",
   "jei.rivencraft.ink_mixer.usage": "Paper + ink makes a Link Panel. One vial fills 16 ink; each panel uses the configured ink cost. The empty vial returns as a glass bottle.",
+  "jei.rivencraft.ink_mixer.additive": "Click this additive into the ink basin: %s. Effects roll when the panel is taken.",
+  "jei.rivencraft.ink_mixer.effect": "%s %s%%",
   "jei.rivencraft.writing.copy": "At a Writing Desk, select a stored Page, add paper and ink, then take the copy. The source Page stays.",
   "jei.rivencraft.writing.bind": "At a Book Binder, name the Age and add a cover plus Link Panel. Optional symbol Pages follow the panel.",
   "jei.rivencraft.writing.linking_book": "Craft one Link Panel Page with leather to make an unwritten Linking Book. Open it to name and bind it.",