Potions are consumables that grants an entity an effect. A player can brew potions using a Brewing Stand or obtain them as items through various other game mechanics.

Custom Potions

Just like items and blocks, potions need to be registered.

Creating the Potion

Let's start by declaring a field to store your Potion instance. We will be directly using a ModInitializer-implementing class to hold this.

public class FabricDocsReferencePotions implements ModInitializer {
	public static final Potion TATER_POTION =
			Registry.register(
					Registries.POTION,
					Identifier.of(FabricDocsReference.MOD_ID, "tater"),
					new Potion("tater",
							new StatusEffectInstance(
									FabricDocsReferenceEffects.TATER,
									3600,
									0)));

We pass an instance of StatusEffectInstance, which takes 3 parameters:

• RegistryEntry<StatusEffect> type - An effect. We use our custom effect here. Alternatively you can access vanilla effects through vanilla's StatusEffects class.
• int duration - Duration of the effect in game ticks.
• int amplifier - An amplifier for the effect. For example, Haste II would have an amplifier of 1.

INFO

To create your own potion effect, please see the Effects guide.

Registering the Potion

In our initializer, we will use the FabricBrewingRecipeRegistryBuilder.BUILD event to register our potion using the BrewingRecipeRegistry.registerPotionRecipe method.

@Override
public void onInitialize() {
	FabricBrewingRecipeRegistryBuilder.BUILD.register(builder -> {
		builder.registerPotionRecipe(
				// Input potion.
				Potions.WATER,
				// Ingredient
				Items.POTATO,
				// Output potion.
				Registries.POTION.getEntry(TATER_POTION)
		);
	});

registerPotionRecipe takes 3 parameters:

• RegistryEntry<Potion> input - The starting potion's registry entry. Usually this can be a Water Bottle or an Awkward Potion.
• Item item - The item which is the main ingredient of the potion.
• RegistryEntry<Potion> output - The resultant potion's registry entry.

Once registered, you can brew a Tater potion using a potato.