nago wrote:I imagine that formula would give extremely overpowered results (as far I know, base damage is multiplicative with weapon skill and fighting)
Maybe not quite so much as you think! In the current system, you get 1 point of additional base damage per 2.6 points of Str with a 15 base damage weapon. (On a quick blade, the rate is 1 per 7.8 Str; on a UC 27 troll, it's 1 per 1.08.)
So, the OP's proposal would be a big buff to low damage weapons, a moderate buff to high damage weapons, and a big nerf to (especially Tmut) unarmed. Since imo low damage weapons could use a buff and Tmut unarmed could use a nerf, I think it's worth considering!
edit:
nago wrote:But +1 to simplify it, maybe treating like 3 points = 1 slay or things like that
Maybe this is better, but the current rate is more like 1 to 1.5 Str per 1 slay for two-handers at high skills, so if you went that way you'd have to make skill increase damage more (maybe not such a bad thing!). On the whole though I really hope something along these lines gets traction. Better balance and simpler math are within reach!
edit 2:
Thinking about this a bit more, n Str = 1 slay wouldn't actually simplify anything. Any flat number you could give would either give overpowered results at low levels or underpowered results at high levels; to adjust for this, you'd have to add complexity somewhere else. That's the beauty of the OP's n Str = +1 base damage proposal, since that just flattens the impact of base weapon damage (subject, crucially, to the cap).