 D6 Adventure is a generic role-playing game system based on a system named after what?
D6 Adventure: D6 Adventure is a generic role-playing game system based on the D6 System. D6 System: The D6 System is a role-playing game system published by West End Games (WEG) and licensees. D6 System:  The system is named after the 6-sided die, which is used in every roll required by the system.
6-sided die