Video game glitches are software errors that either were not caught during the quality assurance testing of the game, or were considered too minor to correct before the game was released.  Glitches can range from a minor distortion to a major malfunction in the game.  Some glitches work in the player’s favor like a cheat code to make the game easier, such as unlimited ammunition or additional lives.  Some glitches are simply amusing or unusual, such as a color variant or character spasm.  Glitches differ from actual cheat codes in that they were never intended to be a part of the game and were not set up deliberately by the designers.

Most glitches are found by accident.  Many times players are doing a "I wonder what would happen if I" scenario, and stumble upon a glitch.  Once a glitch is found, most players will share it with their friends and on websites devoted to glitches.  Many times, when players start new games, they will search on the internet for glitches and cheat codes to make the games more fun or more or less challenging.  Player etiquette gives the original finder the proper credit for discovering the glitch and sharing it with other players.

One famous glitch was in the game World of Warcraft.  This glitch was so famous that it actually was named: Corrupted Blood.  Corrupted Blood ended up being a plague that infected pets, who then passed it on to the owners, spreading the original curse throughout the game to anyone who came in contact with it, forcing players to spread apart and avoid major cities.  The Center for Disease Control actually used statistics from this glitch in their research on epidemics.