This information pertains to an older version of the mod. This information was changed in version 1.5.0.
When applied to a player, that player can create boulders from the ground by right clicking on a block made of rock, dirt, sand or clay material (such as Dirt, Sand or Cobblestone) with an empty hand. Holding right click before releasing will create a bigger boulder.
Boulders float in the space they were created, and can be send as projectiles by hitting them. Boulders disappear after 1 minute, or 3 seconds after being launched. On impact, they deal between 6 () and 20 () damage depending on their size to what they hit. Boulders below the maximum size also disappear on the first mob hit.
The player is also able to stand on a created boulder, and can move with it by sending it while standing on it.