There's plenty of physical fitness programs, such as Hundred Pushups that already effectively give you a leveling system AND an actual training program. I've found them quite useful, although I dropped them as soon as I stopped gaining levels easily.
It doesn't seem like it would be significantly harder to come up with alternatives: A NaNoWriMo training program where you produce 50 words/day for a week, then 100, until you're doing a novel in a month, for example.
I don't see any reason to have "generic" levels which combine physical fitness, problem solving, and socialization, though. There's so much variation even within each of those domains that I'd feel silly even assigning myself a "socialization" score to begin with (I'm horrible at pointless cold approaches, but have absolutely no issues if I genuinely need information from a stranger, for example)
I like the idea of "generic" levels because I'd like other people's appraisals of what they think are standard skills of human competence. (For example, it took me a while to realize that fitness is a standard domain of human competence, and that I was being silly by defining myself as "just not into exercise.")
I just got this random idea that people who want to become better at life could benefit from a common scale of "leveling". No, I don't mean vague Lesswrongey things like "changing your mind". I mean a set of concrete criteria like "you qualify for level 2 if you can do 5 pull-ups, have solved 30 Project Euler problems, and did 10 cold approaches". Obviously there would be separate ladders for different character classes, but not too many. Also obviously, my example was a bit too high for level 2. So I guess I really want to ask some meta questions here:
1) Do you think agreeing on a common leveling scale would be a good thing for a substantial subset of LW users? Would you feel good about leveling up and telling other people about it on LW?
2) Is there some good way to determine leveling criteria that are neither too high nor too low? Maybe make an intermediate scale of "experience points"?