Isn't 'munchkin' sort of taken too? The impression I got from a little googling is that the word as used by RPG players is a derogatory term.

The core of the insult is in the framing of the behavior as a negative (and an assertion of higher status of the speaker). The actual descriptive element of the behavior is a pretty close match to what we are talking about. This is perhaps enough of a reason to discard the word and create a synonym that doesn't have the negative association.

The problem with the MIN-MAXing munchkin - or rather the thing that causes munchkin-callers to insult them is that they think Role Playing Games are about actually taking on the role and doing what the character should do. The whole @#%@# world is at stake so you learn what you need to about the physics and the current challenges. You work out the best way to eliminate the threat and if possible ensure a literal 'happily ever after' scenario. Then you gain the power necessary to ensure that your chance of success is maximised.

But the role of the character is not what (the name-caller implies) the point of the game is about. It is about out what the game master expects, working out your own status within the group and achieving a level of success that matches your station (and no higher). The incentive to the speaker is to secure their higher position in the hierarchy and maintain their own behavior as the accepted model of sophistication. Object level actions are to be deprecated in favor of the universal game of social politics.

Many of the same behaviours and judgments apply to life as well. Optimising for whatever your own preferences are as an alternative to doing what you think you are supposed to do. Optimising your behavior for status gain only if and when status gain is what you want or need.

I don't play roleplaying games myself. I much prefer cards, board games or games that are physical. Both the social aspect and the games themselves are for more fun and the roleplaying just slow, with the 'role' of an individual borderline insulting. If I want to socialise I'll socialise. If I want to hear someone else's story I'll read a book. If I want to play a roleplaying game I'll download one on the computer. If I want to guess the boss's password I'll get a job - and I damn well be being payed well for it.

I may be a little biased. The last time I did, in fact, play a group RPG one of my companions thought it was ok to steal something of mine. I gave her fair warning and plenty of chances to comply but I ended up having to fight both her and her and the two allies she recruited (while the other two in the group stayed out of it.) Once I defeated them I took my pick of their stuff by way of appropriate reprisal. It's exactly what the character I was roleplaying would have done and I wouldn't roleplay a pushover but at the same time the overall social experience isn't especially rewarding. I haven't once had to beat the crap through three of my friends in the real world, which suits me just fine! :)