Boulder

The Boulder is a placeable 2x2 block. Whenever one is unsupported or you use a pickaxe on it, it will roll and deal massive damage. If a rolling boulder hits a wall, it will break and give no drop.

Boulder traps occur naturally in caves (in worlds generated after the 1.1 patch). These consist of a single boulder in the ceiling, supported by several Active Stone Blocks and Wired to Pressure Plates. If the player mines the Active Stone Blocks, or if a player or Enemy walks onto the Pressure Plate, the boulder will fall and deal massive damage in the range of 60 to 150.

Boulders can also be crafted and placed by the player to damage Enemies (and other players in PvP). Crafted Boulders can also damage the player who placed them.

Boulders do not collide with Wood Platforms, and do activate Pressure Plates. At full tilt, boulders roll faster than a player with Well Fed buff, Werewolf buff, full Shadow Armor, a Quick Aglet, a Quick Anklet of the Wind, and 3 other Quick reforged accessories, or Quick Hermes/Spectre Boots when the player is running full tilt with the Hermes Boots, meaning that the boulder cannot be avoided by running in almost any circumstances.