1UP: "Glitches happen. No matter how hard a developer tries or how much QA testing a game goes through, occasionally a bad bit of code will cause conflicts in some unforeseen way. Most of the time these are minor annoyances, and in our modern age such issues often get patched before they impact too many people. Once in a while, though, they turn out to be hilarious, beneficial, or even a vital part of a game's legacy. We've thought up a few of our favorites."