BRP core rule is "roll under your skill on d100" for everything, including combat. Roll under your 80% Rapier, and you hit (unless they roll defense and foul your blow with their cape, rolling under their 75% Cloak&Dagger); roll under your 60% "Heiroglyphics" to be able to translate the words on the tomb door: etc...CoC/BRP is a pretty heavy ruleset right? I don't need a lot of physical combat rules. I imagine combat to be extremely deadly, like even in a duel if two people manage to injure one another, they are both likely to die.
Look to the Hit Location or Major/Minor Wound options to make combat more deadly. 1d8+1 is often incapacitating to a 4-point abdomen, for example!