You know the type. You've set up a wicked cool dungeon for your crew to crawl through, dice are thrown for new PCs, equipment purchased, and you're all ready to hit the ground running. Then that guy pipes up: "Why would my puny wizard risk life and limb in a dank, smelly dungeon?" It never even occurs to most of these blackhearted jackanapes that coming up with a reasonable motivation is their own damn problem. Meanwhile everybody else at the table is smart enough to realize that scoring XPs, winning fabulous prizes, and killing orcs are their own rewards. Why is this stupid git harshing the buzz before the game even starts? Is he really that dumb?
Never again do you have to be caught unprepared for such shenanigans. Just instruct the ill-mannered fool to roll d12.
Random Dungeon Motivations
1) PC is obsessed with proving the existence of the Hollow World.
2) PC quests to retrieve bones of famous adventuring ancestor and re-inter them in family tomb.
3) PC has terrible but enticing dreams of sitting on the throne of a vast underworld kingdom.
4) PC owes d6 x 10,000gp to Jabba the Hutt.
5) PC seeks vengeance against the Troll King.
6) Family member of PC afflicted with disease that can only be cured with the waters from a sacred subterranean spring.
7) PC haunted by visions of a beautiful witch/drow/princess/goth chick living on an island at the center of a vast underground lake.
8) PC seeks one segment of the Rod of Seven Parts. Must obtain all seven to save homeland from foretold doom.
9) Evil duplicate of PC (twin? simulacrum? clone?) has fled into the dungeon. One or the other must die before both go mad.
10) PC's true love has been trapped in amber and is on display in the trophy room of Lord Utterdark.
11) PC's parents imprisoned. Corrupt official will release them in exchange for the Star Ruby of Umman-Gorash.
12) PC quests for legendary sword (fighter), archmage's spellbook (MU), or holy relic (cleric).