Minecraft wiki entry for Defense, associated text: To make a landmine, you need to dig a two-block deep hole. At the bottom of this hole, place a single block of TNT. Next, place any block on top of the TNT. Lastly, place a pressure plate on top of the block that was placed on the TNT. Once an entity steps on the plate, the TNT will explode, thus causing damage to the entity and the terrain.