In role-playing games, focusing on rules details and exploiting them despite how they ruin the game for other players.
In the extreme, taking inky delight in using the rules to ruin the game.
“But the rules say my hafling can throw 10 shuriken, and gets +1 damage with thrown objects, so it MUST mean +10 total.” | “That’s munchkinness. Should an ogre scream like a sissy ‘OMFG! It’s a hafling! Run!’?”