How-to: Add Custom Items

Library of Exile does not mandate a specific item registration pattern, but it provides RelicItem as a base class for relic items and integrates with Forge's DeferredRegister through OrderedModConstructor.

---

Register a basic item

// In your OrderedModConstructor subclass:
public static final DeferredRegister<Item> ITEMS =
    DeferredRegister.create(ForgeRegistries.ITEMS, "my_mod");

public static final RegistryObject<Item> MY_ITEM =
    ITEMS.register("my_item", () -> new Item(new Item.Properties()));

@Override
public void registerDeferredContainers(IEventBus bus) {
    ITEMS.register(bus);
}

---

Register a RelicItem

RelicItem is a minimal single-stack item intended to hold relic capability data:

public static final RegistryObject<Item> AMULET =
    ITEMS.register("amulet", RelicItem::new);

To link it to the relic system, create a matching RelicType JSON — see Add Relics.

---

Register a custom RelicItem subclass

If you need tooltips, special right-click behaviour, or other item logic:

public class RingItem extends RelicItem {

    @Override
    public void appendHoverText(ItemStack stack, @Nullable Level level,
                                List<Component> tooltip, TooltipFlag flag) {
        super.appendHoverText(stack, level, tooltip, flag);
        tooltip.add(Component.literal("A powerful ring").withStyle(ChatFormatting.GOLD));
    }
}

// Registration:
public static final RegistryObject<Item> RING =
    ITEMS.register("ring", RingItem::new);

---

Register a BlockItem

For items that place blocks, register both the block and the item:

public static final DeferredRegister<Block> BLOCKS =
    DeferredRegister.create(ForgeRegistries.BLOCKS, "my_mod");

public static final RegistryObject<Block> MY_BLOCK =
    BLOCKS.register("my_block", () -> new Block(BlockBehaviour.Properties.of()));

public static final RegistryObject<Item> MY_BLOCK_ITEM =
    ITEMS.register("my_block", () -> new BlockItem(MY_BLOCK.get(), new Item.Properties()));

Register both DeferredRegister instances in registerDeferredContainers:

@Override
public void registerDeferredContainers(IEventBus bus) {
    ITEMS.register(bus);
    BLOCKS.register(bus);
}

---

Provide item models and textures

Library of Exile does not handle model generation. Add your own JSON model files under:

src/main/resources/assets/my_mod/models/item/my_item.json
src/main/resources/assets/my_mod/textures/item/my_item.png

A standard generated model:

{
  "parent": "item/generated",
  "textures": {
    "layer0": "my_mod:item/my_item"
  }
}

---

Provide item language entries

// src/main/resources/assets/my_mod/lang/en_us.json
{
  "item.my_mod.my_item": "My Item"
}

---

Notes

• RelicItem calls stacksTo(1) in its constructor — relic items are always non-stackable.
• Items registered with Forge's DeferredRegister are available after FMLCommonSetupEvent. Do not try to resolve RegistryObject.get() before that point.
• ExileKeyHolder.createItems() is an internal helper used by the library's own content. Prefer plain DeferredRegister for your own mod's items to keep the code straightforward.