I had this idea today to make stress, at least partly drive progression. My thinking went thusly. The stress rules in 3e are really transformative to the game but it seems hard to get the players to use it. The idea that a player doesn’t have to fail a roll unless they want to (or are exhausted) is really crucial.
Doing things like lifting weights makes you tired, you’ve stressed your muscles out. So really, taking stress should offer some growth. Only, if you go too far, you’ll injure yourself. There should be a sweet spot in stress that would give growth, but the players shouldn’t go nuts taking stress.
There are three kinds of stress, Physical, Functional and Mental. If hitting a sweet spot gave an experience point apiece, it would seem an acceptable amount. But what is that sweet spot? My first thought is something equal to the attribute, but that may be too high. Maybe something up to the lowest attribute in the stress class but going higher than the lowest attribute negates the bonus. That would allow the player to take one stress and get an experience point, which seems too easy.
If I really wanted to be exact, it would hurt the player to go over the lowest attribute, signifying that they injured themselves. Only, that doesn’t seem like players would really enjoy that.
But this could replace the Active Participant experience criteria. It would go from something subjective that the GM decides, to something the players could prove.