Glitch

A glitch or bug is an unintended behavior of any video game that results from programming errors. Glitches range from characters falling through the floor to the game crashing. An example of a well-known glitch is the Minus World from Super Mario Bros.

When glitches occur, either something unusual happens (such as Mario being able to walk underwater, a glitch in Super Mario Sunshine and Super Mario 64 DS), or the screen freezes and sometimes some random pixels and object tiles appear. Some glitches are caused by damaged game media, even if there are no errors in the game's programming, or other direct interference with the game media, such as cartridge tilting in Super Mario 64. Some activate only when the player presses a certain sequence of button commands. Other glitches, such as the aforementioned Minus World, can actually create new levels occasionally made randomly and haphazardly, and others allow the player to guide their character offscreen. Sometimes glitches grant access to slapdash areas (sometimes composed of many garbled symbols) and unused parts of stages.

One type of programming error that can result in glitches across multiple games is an integer overflow or underflow, where an integer variable, instead of being stopped from increasing from its maximum value or decreasing from its minimum value, instead rolls over from its maximum to minimum or minimum to maximum value. Instances of an integer overflow or underflow causing a glitch are present in Paper Mario and Super Mario 64.

Trivia

 * Glitches have been parodied and even used in the plot of Super Mario games. Examples of this include TEC-XX, who had the "glitch" of falling in love with Princess Peach in Paper Mario: The Thousand-Year Door; Fracktail of Super Paper Mario, who shouts many lines of dialogue spoofing glitches and errors; and the game bugs in WarioWare: Get It Together!, which glitch up WarioWare, Inc.'s latest game and pull the characters into the game.