Video games have a starred history of being susceptible to cheating. After all, any man-made form of content contains within it the seeds of its own dissolution. Video games, in particular, are themselves vulnerable to geing "gamed" by the very nature of their makeup: computer code. No code can ever be completely foolproof. If one person can create it, another can figure out how it was done, then learn how it can be taken apart. This concept gave rise to the tiny industry behind products like the Game Shark, which let players input codes to unlock special features in games, like unlimited lives, invincibility, and in some cases, hidden levels and special screens.

Some of these special powers and tricks were simply a matter of changing certain values around -- mathematical constructs that defined how a character would move, or how a weapon should behave. Other tricks were just palette swaps, giving your favorite characters a new wardrobe, or changing the colors of every onscreen element to their negative values.

Of more interest, however, were the little in-game hacks that could be exploited by those with the skill and perseverance to discover them. Pac-man, for instance, contained a few such weird glitches. For example, there was a way of influencing the ghosts' behavior by positioning Pac-man in distinct ways with regard to their locations in the maze to such an extent that Pac-man could pass directly through them. Another great exploit was getting one of the ghosts to stay in his pen after being eaten while blue, which effectively left the player to contend with only three enemies that level instead of four.

You might not think of these kinds of behaviors as cheating, necessarily. After all, if the underlying code allows for these phenomena to occur, then taking advantage of them isn't really cheating, is it? That depends ultimately on how you look at the act of playing a video game. Is the game a challenge to the player from the developers, saying in essence, "This is the goal, and these are the rules. Try to win, given the restraints." If that's your take on things, then anything outside of strict adherence to presented gameplay is cheating.

But if you consider playing a video game to be a complete experience in and of itself, regardless of developer intent, then you're going to want to wring every last bit of content out of your game, purposeful or not. That can hardly be called cheating, especially when you've bought a game to bring home -- it's just added value. But there's yet another type of cheating to consider.