Save scumming

"Save scumming" is an exploit which occurs in games that let the user save the game for later play. By creating a copy of a saved game, the player creates a state to which they can return to at any time.

The term "scumming" is derived from the process of repeated removing the "scum" or surface debris on a liquid in order to obtain a purified substance. Thus it is used to mean repeated activities in order to obtain the "good stuff". There are various forms of "scumming" possible within various roguelikes, some of which are trivial and some of which are quite cheesy and some of which are blatantly abusive of game mechanics. However, none of these activities is cheating, since the rules of the game allow them.

"Save scumming" or "save file scumming" is keeping a copy of the save file and restoring it in order to undo an undesired result inside the game and redo events in order to get a desired result. This goes outside the rules of the game and is clearly cheating. True "save file scumming" involves things like repeatedly killing a unique in Angband or one of its variants in order to get a great drop or redoing fights with a tough opponent until you come out with a minimum of expendible resources used up. Anything that you can "reroll" by redoing slightly differently can be scummed in this way.

"Save scumming" is also used, rather incorrectly (as this is not typically a "scumming" type activity -- but perhaps there is some hesitation to call cheating by its proper name) to using save file restoration to evade permadeath, a standard Roguelike game feature. This will let the player try something potentially dangerous with no risk. Stand and fight a dragon that can instakill you if it breathes in the first three rounds of combat -- if you die, just restore and try again. Play carelessly, do something stupid and die -- restore and avoid your mistake. While one can cheat death in a scummish manner, tediously trying over and over to get a series of lucky criticals to take out a tough monster, it is much more typically done to undo mistakes made during play in order to not restart with a new character.

Someone who choses to cheat at a single-player game is doing no harm, except perhaps to himself, so as long as you don't post a victory post with a character who used save file abuse or add it to a shared high score list, nobody much cares, except for the sake of the cheater. Generally speaking, lessons stick better when they have consequences. You become a better RL player by making mistakes, dying, and *not repeating the mistake*. Cheating your way around the consequences slows learning. On the other hand, in addition to playing technique, there is a learning curve for what items and monsters you encounter in a game and some have said that save file abusing their way to a first "victory" in order to preview the late game was helpful in eventually achieving a real win.

Counter-measures

• Do not let the player have control of the saved games (have the player connect to a games server, for example)

• Unless you require the player to play on a server you control, it is pretty much impossible to prevent save file abuse, so it is widely considered a waste of time to spend much effort on technological solutions. There is, however, a less coercive alternative: persuasion. A good, clear explanation of why you actually die when killed in the game ought to be in the basic game manual. Instead of trying to prevent a replacement savefile from being used, why not just detect it and issue a warning that doing so for reasons other than a game crash/power failure is cheating? If someone wants to cheat, you aren't going to stop him, but you can try to make him actually think about and decide if he really wants to.