Here are two prime examples, suitable for gaming inspiration:
Myrra is the fantasyland that rock musician Jim Rook, and his girlfriend Janet Jones, get transported to in Nightmaster, starting in Showcase #82 (May 1969). Rook is revealed to be the descendant of Nacht, an ancient warrior of Myrra, and the only one who can wield his ancestor's Sword of Night, and save the world from the evil Warlocks. Nightmaster was the of writer Denny O'Neil and artist Berni Wrightson. As some of the place names on the map might suggest (Duchy of Psychos, for instance) there was a bit of a late sixties camp element to Nightmaster's adventures, but not as much as some of the names might suggest. Nightmaster ran through just three issues of Showcase."I feel like a character from Howard or Tolkein. Pretty soon, though, I'm gonna wake up and find this is a spaced-out dream. And I'm gonna swear off reading sword-and-sorcery sagas!"-- Jim Rook, Showcase # 82 (1969).
"...On a nameless world in a forgotten time..." is a pretty typical beginning for these sorts of things, and that pretty much sums up Wulf the Barbarian. The series was from Atlas/Seaboard Comics (helmed by Stan Lee's brother Larry Lieber) and ran for four issues in 1975. Wulf is the son of royalty, orphaned when trolls in the service of an evil sorcerer, killed his parents. Wulf spends the next decade training as a warrior to reclaim his kingdom. As one might imagine, the road to reclaiming that throne is potholed with a number of fantastic obstacles. Wulf was written and drawn by Larry Hama, and inked by Klaus Janson for his first two outings, with multiple creators pitching in on the last two. This map is from Wulf the Barbarian #3.