Initiative and weapon speed factor
Roll d6+damage dice of the used weapon. Okey, from now on scoring lower in initiative rolls means better.
No level drains instead ability drain.
So in most of the osr games demi-humans have restrictions on leveling in some classes. In the Barbaric Frontier it's the opposite. Humans can level up to 10th level in every class, while the demi-humans can level up to 15th level.
Dwarves can reach 15th level due to their long lifespan and anatomical superiority over humans. Elves also can reach 15th level due to their long lifespan and greater than human wisdom. Only halflings are the exception in this case - they can reach 12th level.