GURPS

GURPS is a role-playing game by Steve Jackson games, well-known for having a robust library of material, complex rules encapsulating many tactical choices and an intimidating array of options for character creation and play.

GNS[1]: Strongly Simulationist
Genre: Varies
Setup: Substantial
Play Style: Strict
Players: 2+ including GM
Mechanics: d6's only; frequent rolls
Typical Session Length: 4+ hrs.