TNT is an explosive block with a default effective radius of three blocks, (3m^3). To detonate TNT the player must first find the TNT Detonator Relic. Once placed, a TNT block should detonate immediately, if the game is busy the explosion can be delayed. In this case the block will emit sparks until detonation. It is also possible to stop a tnt explosion by placing a block over it. TNT is found on the 2nd Block Wheel.
This block is useful for clearing large expanses of land in a short amount of time, but it is advised you take care when using it (see: "Help! I blew my Workshop up!").
The radius of the TNT explosion can be changed with Console Commands up to a maximum radius of 32, this is done using the command, "SetTNT [#] Confirm." Warning: with larger sized TNT the game is prone to slowing down due to the amount of blocks being removed.
Clients in a game are unable to use TNT. This measure is to prevent griefing, though it has been hinted at by DjArcas that it may be possible to allow certain players access to TNT in the future through player permissions in the future.
TNT was released on April 8, 2011, with the release of the game.