Even though the programmers or creators of video games may refer to glitches as errors, for those that just can't seem to figure a certain part of a game out, or just can't get through that last level, they are a savior. The word, "glitch," among gamers, has practically become synonymous with the word, "cheat." Even with this being the case, not all glitches are good. Often times they lead to games freezing or other annoying effects.

A lot of the time glitches are just something to go back and mess with. Most of them will not really help with completing a game or freeze the game altogether. They may just be an interesting graphic or something equally as pointless yet amusing. For example in the Pokemon GameBoy games there is a cheat that can be used where your character can stand on a tree. It doesn't really help you but it is kind of funny to look at.

As for the glitches in Quake 2, they just make the game more fun. The double jump and the rocket jump were not intended to be in the game but they are and the glitch is so easy to use (unlike many that are so hard to activate that they hardly even matter) that it is hardly even regarded as a glitch.

If the programmer forgot to include a special case, or maybe just as importantly if the game tester failed to test specific cases, then it can be simpler to complete a game. Whether it is advantageous to do so with a glitch or to beat a game straight up is for the gamer to decide.