So I have a Radiant Silvermail that gives me Damage Bonus v. Undead Medium along with a Skolver Cap with Damage Bonus Increase Medium, and the sword in my first slot states both Damage Increase Medium and Damage Bonus v. Undead Very High. So in terms of attacking undead, am I correct in assuming that only the Damage Bonus v. Undead Very High applies, or do they both stack?
Question on Damage Bonus Increase
Lemme show you how this works in terms of numbers:
Low = 1
Med = 2
High = 3
Very High = 4
Ultra = 5
Maximum! = 6
Skolver = +2 Everything
Silvermail = +2 Undead
Damage bonus from armor: +2 Everything, +4 Undead (Undead is added to Everything when fighting that Monster Family)
Ergo, damage bonus from armor = Med vs. Everything, Very High vs. Undead
If Sword Damage is what you're looking for, you'd want to go with Skolver Coat instead of Silvermail. That'll give you +4 to Everything instead of just Undead.
Does that explain it for you?
There now, this could be solved trough a quick look at the wiki...
If you open your character tab and hover over your weapon icon on the bottom, it tells you. Only one line of bonus applies. There might be an extra line, damage vs family, if you happen to have family damage bonus. In which case, your bonus family damage will be added to damage bonus and counted as a separate line.
This is explained at the wiki page "Abilities".
the indicators on the bottom show your bonuses after they are already stacked.
So your sword has medium + medium vs. undead which makes it very high on undead, medium on everything else.