* Reality may vary.

Event Probabilities (made up)
30%Kill a critter or group of critters, scaled to PC's level
30%Loot an item, 10% from NPCs, 90% from mobs
5%Kill an NPC
5%Cast a spell on a group of critters, spell and critters scaled to PC's level
5%Sell random equipment, scaled to PC's level - 5
5%Buy random equipment, scaled to PC's level
5%Starting quest
5%Finishing quest
7%Plot string
3%Loading message

Strings (almost) straight from pq.exe