A recurring gag around my game tables is that as we’re about to engage the enemy, open a scary door or do something else risky/stupid, someone says “save the game”.
There are very few systems where this is actually an option.
I’ve seen the occasional retcon of a TPK or some other major turning point by group agreement, but I rarely see it suggested by the rules themselves. Marvel Super Heroes SAGA has an optional “What If?” rule to change things, to pick one example I can think of.
Would you limit the number of saves? I tend to save a lot if I have the option to in computer games. I wouldn’t overdo it in an RPG, because there’s a lot more to remember and no system doing it automatically.
Alternatively, what if it’s something the characters can do?
Edge Of Tomorrow (which is a lot of fun) got me thinking about this. The main character gains the ability to reset back to when he woke up that morning - by dying. Like an alien invasion Groundhog Day, not unlike Source Code. This allows him to learn to avoid a variety of unpleasant deaths, although if it were up to him he would have chosen a different “save point”.
The indie console game Braid does something similar, making going back over events a key part of gameplay.
See also Prince Of Persia: The Sands Of Time for a deliberately limited version where the time warp only goes back a few “rounds” and runs out eventually. A PC might bend the game but probably not totally break it.
And there are enough Groundhog Day episodes of genre TV series that it’s on many lists of staple story ideas and has its own TV Tropes page. Buffy and Angel both did as part of a larger threat in one episode each, so I left it out of The Watch House.
Edge Of Tomorrow involves time travel, so that genre is the natural place to include this kind of thing.
TimeWatch is built around time travel tricks like coming back to save yourself in a fight, so establishing a save point seems to fit as well. A time effect with a “dead man switch” set to go off it certain criteria are not met?
Other kinds of save point includes backup bodies (often seen in transhuman SF games and vital in Paranoia) as an in-universe explanation of multiple lives, although that just lets you come back from death rather than restoring the things that lead to it.