Tutorials/Falling blocks

FallingSand has two important NBT Tag fields that change the appearance, movement, and lifetime of the entity.

Most notable of the is BlockID. Using a BlockID for FallingSand in /summon grants the player the ability to, for example, create a falling bedrock block. ('/summon FallingSand ~ ~ ~ {BlockID:7}'). Note that even though as of 1.8 Minecraft has moved to item ID's of 'minecraft:stone' etc., the BlockID still uses the number format.

The other important tag is Time. Time stands for the time (in ticks) for how long the FallingSand has existed. If 0, the entity despawns, if 1 or greater, will continue ticking up, until it reaches a maximum lifetime. This means if the player wants to have a falling bedrock block that does not despawn immediately, then they should put that in the NBT tags ('/summon FallingSand ~ ~ ~ {Block:"minecraft:bedrock",Time:1}'). When the maximum lifetime is achieved, the FallingSand will despawn and (unless the data tag '{DropItem:0}' is set) drop the block as an item. In normal conditions the maximum lifetime will not be reached, but using a command that would make a FallingSand ride another entity, would stop it from falling, and therefore from becoming a normal block. If this is done, the Time will be ticking up until the maximum lifetime is reached.