Basic items can only go so far - eventually you will need an item that interacts with the world when it is used.

There are some key classes you must understand before taking a look at the vanilla item events.

InteractionResult

An InteractionResult tells the game the status of the event, whether it was passed/ignored, failed or successful.

A succesful interaction can also be used to transform the stack in hand.

ItemStack heldStack = user.getStackInHand(hand);
heldStack.decrement(1);
InteractionResult.SUCCESS.heldItemTransformedTo().success(heldStack);

Overridable Events

Luckily, the Item class has many methods that can be overriden to add extra functionality to your items.

INFO

A great example of these events being used can be found in the Playing SoundEvents page, which uses the useOn event to play a sound when the player right clicks a block.

Method	Information
hurtEnemy	Ran when the player hits an entity.
mineBlock	Ran when the player mines a block.
inventoryTick	Ran every tick whilst the item is in an inventory.
onCraftedPostProcess	Ran when the item is crafted.
useOn	Ran when the player right clicks a block with the item.
use	Ran when the player right clicks the item.

The use() Event

Let's say you want to make an item that summons a lightning bolt in front of the player - you would need to create a custom class.

public class LightningStick extends Item {
	public LightningStick(Properties settings) {
		super(settings);
	}

}

The use event is probably the most useful out of them all - you can use this event to spawn our lightning bolt, you should spawn it 10 blocks in front of the players facing direction.

@Override
public InteractionResult use(Level world, Player user, InteractionHand hand) {
	// Ensure we don't spawn the lightning only on the client.
	// This is to prevent desync.
	if (world.isClientSide()) {
		return InteractionResult.PASS;
	}

	BlockPos frontOfPlayer = user.blockPosition().relative(user.getDirection(), 10);

	// Spawn the lightning bolt.
	LightningBolt lightningBolt = new LightningBolt(EntityType.LIGHTNING_BOLT, world);
	lightningBolt.setPos(frontOfPlayer.getCenter());
	world.addFreshEntity(lightningBolt);

	return InteractionResult.SUCCESS;
}

As usual, you should register your item, add a model and texture.

As you can see, the lightning bolt should spawn 10 blocks in front of you - the player.