Slayer is a first-person dungeon crawler based on Advanced Dungeons & Dragons. Create a custom character or choose one of a number of prebuilt characters then delve into a randomly generated dungeon. The game was followed up by Deathkeep.

Though this came out before DeathKeep it's a much better game. There is a surprising amount of customization for a dungeon run, from custom or preset characters to a number of dungeon options to tailor difficulty. Gameplay feels like a fantasy themed Doom/Wolf3D with real time combat. The in game map is very useful showing the location of enemies and items. The last level of each dungeon is one of a handful of bosses. If you're going to play one of the Dungeons & Dragons action RPGs on 3DO then this would be the one to go with.