Talk:Gilgamesh/@comment-2602:306:83F6:2A90:5C53:1395:B9D2:52DA-20171121024350/@comment-28173716-20171121170157

It's the later. Check the post below for full Dmg calculating method.

http://blogs.nrvnqsr.com/entry.php/3309-How-is-damage-calculated

The rule when calculate dmg is: All buffs are multiplicative, except the same type of buffs (they are additive).

Note: Attack buffs on your team and Defence debuffs on enemies are considered as the same type of buffs, so they are additive. For example, your servant has 10% atk buff attacking an enemy with 10% def debuff will give the same result as the said servant has 20% atk buff instead of having 21% (1.1*1.1=1.21)