De Bellis Vietnam is a set of DBA-based quick and dirty rules for wargaming Vietnam.
Low Level Hell is a set of free wargames rules for helicopter actions in Vietnam.
Recon, The Role Playing Game Of The Vietnam War was published in 1982 by Role Playing Games, Inc.
Nam ’69 is a set of free wargames rules for company level rules in the Vietnam Conflict. In the game the players control American squads, while a referee controls the Communist forces.
Other game resources:
Dinky Dau is a set of free wargames rules for skirmishes games set in Vietnam.