Ragnarok (released in Europe as Valhalla) is a freeware Roguelike video game for MS-DOS, developed by Norsehelm Productions (Thomas F. Boyd and Rob Vawter) from 1992 to 1995.

[citation needed] Ragnarok is based on Norse mythology, with many of the gods, realms, items, and quests drawing directly from it, such as: Ragnarok has multiple features uncommon amongst roguelike games, such as a graphical interface, a historical or mythological setting, set quests, the ability to change classes, and the ability to permanently change one's race via polymorphing.

The review felt that Ragnarok may become "a genre-defining game" on a par with Dungeon Master, with a design "serious enough to be competitive with the more sophisticated kinds of play previously only possible in paper form."

The review noted that the game was unique in its "systemic" and "virtually complete" reliance on Norse mythology, and compared the gameplay to Rogue in its elegant simplicity and addictiveness.

[1] Computer Gaming World called Ragnarok "an exploration and item management exercise of the most mind-swamping sort" with a primitive interface and repetitive, number intensive gameplay, recommending it as "a diversion for only the most stalwart and easily amused adventurer.