Glitch

Glitches are the term for when something strange happens in a Mario game, as well as any other game. Two examples of glitches are Dark World and Minus World.

When glitches happen, either something weird will happen (such as Mario being able to walk underwater a glitch in Super Mario Sunshine) or the screen will freeze and sometimes some random pixels appear on screen. Some glitches are caused by damaged games. Some only activate when the player presses a certain sequence of input commands (pressing buttons). Also, as seen in Super Mario 64, if a person is to tilt the game console itself, Mario's limbs will be dislocated and become really weird, although players can still play in that position. Other glitches, such as the aforementioned Minus World, can actually create new levels occasionally made randomly and haphazardly, and others allow players to guide their character off-screen, sometimes granting them access to other glitch-like areas and unused parts of stages. (An example of such a glitch is one found in Super Mario Land 2: Six Golden Coins; this glitch is executed in a Tree Zone stage and lets Mario bump his way to a set of garbled symbols on the bottom of a level, most of which act as Brick Blocks despite their graphics.)

Trivia

 * Glitches have been parodied and even used in the plot of 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, and Fracktail of Super Paper Mario, who shouts many lines of dialogue spoofing glitches and errors.