A Diabloesque hack and slash adventure game with RPG elements in a 3D world.

Quoted from http://www.microsoft.com/games/dungeonsiege/:

"Dungeon Siege combines the immersive elements of a role-playing game with over-the-top intensity and non-stop action. Dungeon Siege plunges you into a continuous 3D fantasy world where you face off against an army of evil that has been unleashed."