[Sir Michael]

I thought according to official D&D rules you could backstab with any legal thief weapon. Even though it's called backstab, the whole idea is that by having a good knowledge of an opponent's anatomy, a thief can pick the most vulnerable spot where they are unaware and so could act to avoid all or part of the strike (hence the "back" part), and do a lot more damage potentially than a normal blow. Why not use a club or staff? It seems like you could easily kill someone by whacking them really hard in just the right spot.