Minus World

The Minus World is a glitch found in Super Mario Bros. It is an underwater level that has no end, meaning that once there, Mario or Luigi is doomed to die by either running out of time or by being killed by enemies. The level got its name because, when in the Minus World, the top screen says that Mario is in World 0-1, effectively World -1 (or Minus World).

To get to the Minus World, Mario must go to World 1-2 and stand on the pipe that leads to the flagpole at the end of the level. Mario should break two blocks, leaving the one to the far right. Now, Mario should move to the far left end of the pipe, facing left, and jump into the air. Mario should then move right while in midair. When Mario comes back down, he should move through the wall and appear in a warp room (if everything was done correctly). Once the worlds in the room appear, Mario should enter the pipe to the far left, and the plumber will find himself in the Minus World.