TNT

TNT acts like a normal block in Creative, but in Survival it behaves like the Creeper's explosion. Upon being struck by the player, it will start smoking and flashing white. If there are no blocks to hold up the TNT block, activating it will make it affected by gravity and it will fall. After 4 seconds, it explodes, destroying a vast amount of blocks, mobs that are nearby, and even the player if they are not careful.

Removing TNT can be tricky, and varies by game. In Survival Test, hitting it two times would stop the countdown and cause the TNT to revert into a resource block which could then be picked up. In Beta, there is no way to pick up TNT after it has been placed, but it can still be safely removed from the world by placing water atop the TNT, thus immersing it in water. Once it has been completely immersed in water, detonate the TNT.

Setting TNT on fire activates it after a while. However, if the TNT falls in water, the explosion will not destroy any blocks at all but still cause damage. Water, stationary lava, obsidian and bedrock are indestructible to TNT explosion.

TNT in water might not be a good mob/player trap, because it will probably destroy any items dropped.

TNT blast will destroy surrounding blocks depending on blocks material. Explosion propagates farthest (loses power the least) through air. This is why an explosion in the open will create the largest destruction radius, but a TNT immediately enclosed in rock will destroy an exact 3x3x3 cube from its center. This feature can be used to confine an explosion differently to make shaped blasts, for example to blast long smooth hallways.

Since the Redstone update, TNT monster traps can now be created and used successfully, making TNT a valuable resource and a powerful defense. When exposed to a current, the TNT activates as if it had been activated by a player. Combine this with a Pressure Plate and you can create an automatic defense for your buildings (Although a one-time-use, as the TNT needs to be replaced).

For the TNT to receive the circuits signal, the redstone needs to be directed straight into it from at least one of four sides, from either the Layer the TNT is based on, or above or below one layer. Diagonally adjacent entry will not make a connection. Finally, Redstone running alongside TNT will also not work due to existing limitations, as it will not branch out into 'T' or 'X' junctions to connect successfully.

Primed TNT
WARNING! The following text contains extremely nerdy verbage. Please do not be offended if you do not understand any of the said text. If you wish to take the risk of brain explosion, however, read on.

A primed TNT is an entity in Minecraft world. It is spawned at the center (+0.5,+0.5,+0.5) of a destroyed TNT block, while itself is a cube with an edge length of 0.98. Its fuse lasts 80 ticks or a random number in [10, 30] if it's destroyed by an explosion.

Once spawned, the primed TNT is given a 0.2 vertical velocity, and a 0.02 horizontal velocity with a random direction in [0, 2π] degree. It was supposed to be random in all direction, but Notch mixed up degrees with radians, as a result the primed TNT will always start to move towards east and slightly north. If not colliding or interacting with anything except the ground, it will travel 0.166m horizontally on a flat ground before it stops and explodes.

Its position and movement is recalculated at every tick.
 * Gravity makes it accelerate vertically downwards with an acceleration of 0.04.
 * A movement of position is applied according to its velocity and collision.
 * Atmospheric drag makes it slow down by 2%.
 * If it is on the ground, its horizontal velocity decreases 30%, its vertical velocity 150%.

Finally after 80 ticks, the primed TNT explodes.

Mining
TNT-mining might be faster than mining by hand but is impractical - about 70% of the blocks are completely destroyed beyond recovery in the process. Nevertheless, TNT can be a part of efficient mining techniques - as the means of removing unneeded layers of blocks and exposing underlaying layers.

Trivia

 * A TNT block will not explode instantly when hit by other TNT explosion, instead it will be activated and pushed away by the blast. (TNT Cannons are built upon this effect). Though, in this case activation time would be shorter than if activated by normal means. This is why in TNT Cannons the projectile TNT is usually activated separately by normal means - to have control over, or to maximize the time before the projectile explodes.


 * Arrows attached to TNT will fall off when activated. This can be used to create arrow cannons.


 * A player or mob sitting in a minecart will take minimal damage from TNT, even when right next to the TNT. This can be used to make people/mob cannons.


 * When TNT is active, objects can go through the block; like water, mobs, and the player. This principle is also used for TNT Cannons.


 * Sand and Gravel blocks will react accordingly to a detonation, scattering from the point of origin.


 * The name "TNT" is technically incorrect. Visually, the block resembles a collection of sticks of dynamite, which is an entirely different explosive frequently confused with TNT. The crafting recipe for the TNT block references the manufacture of dynamite, which is made by stabilizing nitroglycerin with an absorbent material such as sawdust or earth. However, sulfur is not a component of either explosive, but it is in fact used in the making of gunpowder, which is yet another unrelated explosive.

TNT