Questions about Cheat Codes

[inlayterms]

As most of you are aware, a lot of games have "cheat codes" that allow different "perks" such as invincibility, unlimited ammo, one-shot kills, etc.

I know a lot of gamers are against cheats but, notwithstanding whether or not they are fair, I was wondering "how do cheat codes come to be?" Specifically, are they incorporated into the programming by the developers? Are they leaked to the public by the developers or are gamers left to "decode" the cheats? Or are they simply "accidental" results of the programming?

While I don't have any answer to these questions, I speculate that, sometimes, cheats are incorporated into the programming by the developers after the game has been completed in order to make the game more "playable", especially on higher difficulty levels.

Take Dead Space, for example. One of the available cheats allows you to refill the statis meter when the game is paused. I think that the cheat was put in because, on the impossible difficulty level, the game would be, well, impossible to beat and the developers had to put the cheat in there to make the game playable, rather than going through the extra process of putting more statis tanks in the game.

Does anyone have any knowledge, or thoughts, they can add?