How do resistances add up

Grim Dawn Modding - Tutorials and Help
1

I was checking Darius Cronley’s data (banditleader_darius.dbr) and saw he has 15% Pierce resistance (character bio > natural resistance) but he also has the skill darius_passiveproperties.dbr which also has 15% Pierce resistance

The wiki page for him says he has 15% pierce, so do they not add or is the wiki wrong?

2

They probably stack, we had a lot of misinformation in the wiki it turns out. I’d love to publish a list of all boss resists and damage types, but it would be a lot of information to gather and I’m distracted.