I am programming a browser game that is based on Urban Dead (open PvP zombie apocalypse) and Nexus Wars (exploration, open PvP, biblical good vs evil).

Mine will be open PvP + exploration, set in a fantasy world with heavy magic (spells, magical items, potions etc). Like Urban Dead and Nexus Wars, the focus is on players exploring the game world for interesting bits of lore, and finding other players to kill. In fact, killing other players is the primary way to gain EXP and level up.

Initially, I had a "tournament" backstory like Quake/Unreal but that does not work well with exploration. In Urban Dead, you are exploring a post apocalyptic city. In Nexus Wars, you are exploring the afterlife. It isn't so interesting to be exploring a tournament arena.

So, can you guys recommend a backstory that works with my game?