Blocks

Blocks are, obviously, essential to the Minecraft world. They make up all of the terrain, structures, and machines. Chances are if you are interested in making a mod, then you will want to add some blocks. This page will guide you through the creation of blocks, and some of the things you can do with them.

Creating a Block

Basic Blocks

For simple blocks, which need no special functionality (think cobblestone, wooden planks, etc.), a custom class is not necessary. You can create a block by instantiating the Block class with a BlockBehaviour$Properties object. This BlockBehaviour$Properties object can be made using BlockBehaviour$Properties#of, and it can be customized by calling its methods. For instance:

• strength - The hardness controls the time it takes to break the block. It is an arbitrary value. For reference, stone has a hardness of 1.5, and dirt 0.5. If the block should be unbreakable a hardness of -1.0 should be used, see the definition of Blocks#BEDROCK as an example. The resistance controls the explosion resistance of the block. For reference, stone has a resistance of 6.0, and dirt 0.5.
• sound - Controls the sound the block makes when it is punched, broken, or placed. Requires a SoundType argument, see the sounds page for more details.
• lightLevel - Controls the light emission of the block. Takes a function with a BlockState parameter that returns a value from zero to fifteen.
• friction - Controls how slippery the block is. For reference, ice has a slipperiness of 0.98.

All these methods are chainable which means you can call them in series. See the Blocks class for examples of this.

note

Blocks have no setter for their CreativeModeTab. This is now handled by the CreativeModeTabEvent$BuildContents if the block has an associated item (e.g. BlockItem). Furthermore, there is no setter for translation key as it is now generated from the registry name.

Advanced Blocks

Of course, the above only allows for extremely basic blocks. If you want to add functionality, like player interaction, a custom class is required. However, the Block class has many methods and unfortunately not every single one can be documented here. See the rest of the pages in this section for things you can do with blocks.

Registering a Block

Blocks must be registered to function.

caution

A block in the level and a "block" in an inventory are very different things. A block in the level is represented by an BlockState, and its behavior defined by an instance of Block. Meanwhile, an item in an inventory is an ItemStack, controlled by an Item. As a bridge between the different worlds of Block and Item, there exists the class BlockItem. BlockItem is a subclass of Item that has a field block that holds a reference to the Block it represents. BlockItem defines some of the behavior of a "block" as an item, like how a right click places the block. It's possible to have a Block without an BlockItem. (E.g. minecraft:water exists a block, but not an item. It is therefore impossible to hold it in an inventory as one.)

When a block is registered, only a block is registered. The block does not automatically have an BlockItem. To create a basic BlockItem for a block, one should set the registry name of the BlockItem to that of its Block. Custom subclasses of BlockItem may be used as well. Once an BlockItem has been registered for a block, Block#asItem can be used to retrieve it. Block#asItem will return Items#AIR if there is no BlockItem for the Block, so if you are not certain that there is an BlockItem for the Block you are using, check for if Block#asItem returns Items#AIR.

Optionally Registering Blocks

In the past there have been several mods that have allowed users to disable blocks/items in a configuration file. However, you shouldn't do this. There is no limit on the amount of blocks that can be register, so register all blocks in your mod! If you want a block to be disabled through a configuration file, you should disable the crafting recipe. If you would like to disable the block in the creative tab, use a FeatureFlag when building the contents within CreativeModeTabEvent$BuildContents.

Further Reading

For information about block properties, such as those used for vanilla blocks like fences, walls, and many more, see the section on blockstates.