You are wearing armor parts which combined give you 200 defense and 20% bludgeoning resistance.Monsters do 'monster' damage (only witcher gear provides a percent-resistance against this).Humans and non-humans (elves, dwarfs.) do 'slashing', 'piercing' or 'bludgeoning' damage, depending on their weapon.
I recorded the numbers in a spreadsheet and came to the following conclusions: Because sadly nobody felt like answering this question despite the 100 point bounty I had to torture Geralt in the name of science and let some low-level nekars beat him up in various stages of undress.
