House of Boom
Steve places a giant Piston in front of himself, which then extends outwards to hit any opponents in range. The first victim caught is taken into a cutscene where they are thrown into the House of Boom, a structure filled with TNT and Mobs. Creepers and Zombies attack the victim, producing an explosion. Steve enters the frame and eats a victory steak, after which the victim is launched. Any other opponents struck by the Piston will take knockback from it.
In Minecraft, pistons are crafted with three planks of wood, four cobblestones, one iron ingot, and one redstone. They can push other blocks, mobs, and players around when given a pulse through a redstone circuit. The giant piston Steve summons in Smash does not naturally occur in Minecraft, and exists solely for the purposes of the Final Smash.
While the House of Boom does not naturally appear in Minecraft, it bears a strong resemblance to both strongholds and jungle temples, structures that naturally generate in the Overworld. The former serve as the only entrances to the End dimension, where the fight against the Ender Dragon takes place (although unlike the House of Boom, strongholds are found underground rather than on the surface) and the latter contain chests guarded by traps. There are also structures in Minecraft that contain harmful traps, such as desert pyramids, structures which contain rooms with chests filled with valuable loot and a pressure plate that can activate TNT hidden underneath, should an unsuspecting player fall onto it.
Masahiro Sakurai stated that the Final Smash was inspired by seeing players create buildings filled with traps to harm their opponents. The first-person perspective seen just before the explosion resembles Minecraft's default camera mode, with the irregular movement characteristic of a computer mouse.