Battle Scarred Veterans Go Hiking

The PCs are normal people - well, slightly subnormal, though not as low as LARPers. The GM's job is to put sub-normal characters into stressful situations until the GM feels better about what the players did to him/her in their last D&D game. That should teach them to be rules lawyers! Simple rules, d100 system, much flexibility on the part of the GM is required.