Yeah, thats a pretty easy houserule. It will definitely shift the balance of the game a bit, though (generally making Thieves and Pirates quite a bit weaker).Tegman said:True, after reading this, I'll update my house rule so a thief must successfully use Finesse (DV+DR) to be able to add his sneak attack damage to his attack.
In particular, I also think it will hurt Str-based characters who want to multiclass and get a level or two of Thief (such as Conan himself did). If you're not very good at finesse attacks (or you fight with a non-finesseable weapon) then you won't be able to use your sneak attack ability at all. Tegman, your original houserule didn't have this problem, so I think it was slighty better (but a bit more complex).
Things will also shift a bit so that now armour is a very viable defense against sneak attacks, instead of a high Initiative and Improved Uncanny Dodge being the best way to go. A little bonus for the heavily armoured, but slow, Soldier methinks.