@Override public void onUpdate(BlockMaterial oldMaterial, Block block) { super.onUpdate(oldMaterial, block); if (!block.translate(BlockFace.BOTTOM).getMaterial().isPlacementObstacle()) { // turn this block into a mobile block Entity e = block .getWorld() .createAndSpawnEntity(block.getPosition(), FallingBlock.class, LoadOption.NO_LOAD); e.add(FallingBlock.class).setMaterial(this); block.setMaterial(VanillaMaterials.AIR); } }