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
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$Properties#of, and it can be customized by calling its methods. For instance:
strength- The hardness controls the time it takes to break the block. It is an arbitrary value. For reference, stone has a hardness of 1.5, and dirt 0.5. If the block should be unbreakable a hardness of -1.0 should be used, see the definition of
Blocks#BEDROCKas an example. The resistance controls the explosion resistance of the block. For reference, stone has a resistance of 6.0, and dirt 0.5.
sound- Controls the sound the block makes when it is punched, broken, or placed. Requires a
SoundTypeargument, see the sounds page for more details.
lightLevel- Controls the light emission of the block. Takes a function with a
BlockStateparameter that returns a value from zero to fifteen.
friction- Controls how slippery the block is. For reference, ice has a slipperiness of 0.98.
All these methods are chainable which means you can call them in series. See the
Blocks class for examples of this.
Blocks have no setter for their
CreativeModeTab. This is now handled by the
CreativeModeTabEvent$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.
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.
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
Item, there exists the class
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
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
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
For information about block properties, such as those used for vanilla blocks like fences, walls, and many more, see the section on blockstates.