Glitching

Glitching is an activity in which a person finds and exploits flaws or glitches in video games to achieve something that was not intended by the game designers. Gamers who engage in this practice are known as glitchers. Glitches can help or disable the player.

"Glitching" is also used to describe the state of a video game undergoing a glitch. The frequency in which a game undergoes glitching is often used by reviewers when examining the overall gameplay, or specific game aspects such as graphics. Some games such as Metroid have lower review scores today because in retrospect, the game may be very prone to glitches and be below what would be acceptable today.

Video game glitches that go "out of bounds" are mostly performed by either moving through walls or corners or jumping to places in the map that do not have invisible walls. For example, in Tony Hawk's Underground 2, in the L.A. level there is a glitch that can allow players to leave the provided play area and pass through the background. Another example of this is a glitch on the Nürburgring track in Gran Turismo 5 where if the player squeezes through any gap between the walls, the car can drive through the scenery and under the paved course and can finish a lap or the race faster than usual by driving directly under the finish line in the direction of the race's path. Another example in the Need for Speed series is Need for Speed: World. In Rockport there is a spot where you can glitch in Point Camden near Bay Bridge.

In "out of bounds" areas, many maps have hollow objects that the player can move through freely. These objects usually are in the distance and are for decoration. The floor or terrain can also be hollow. The floor can appear the same as a normal floor, but moving over it will cause the player to fall as if it does not exist. Depending on the game, after falling a certain distance the player will freeze, die, respawn on the map again or just keep falling. Two good examples are the Nintendo 64 games The Legend of Zelda: Ocarina of Time and The Legend of Zelda: Majora's Mask. In the former, there is a section of "wall" at the entrance to the water temple that will allow players to fall through the ground. Eventually players respawn rather than the game crashing. In the latter, there is a 3-day cycle (after which the moon will fall) that can be surpassed by going to the observatory and looking out the telescope on the last minutes of the final day. If you look out the telescope while the timer is counting down and exit the telescope when the timer hits 0, (if you're lucky) the timer will be gone and you can continue the game without it. The glitch is removed when you play the Song of Time.

...
Wikipedia