A set bonus is some type ability, attribute, power or spell bonus that gets added when a character has some specified number of items from a set (usually armor) equipped.
Sets can have multiple set bonuses depending on the minimum number of items in the set to activate the bonus (i.e. (2) Set: bonus, (4) Set: bonus).
- Patch 7.0.3 (2016-07-19): Set bonuses for item sets from expansions prior to Warlords of Draenor have been deactivated, though the text describing their former function still remains.
- Legacy sets will show a teal text with "Legacy Set: Bonus is inactive"