Stacking

Stacking rules control how bonuses and penalties are added together. For simplicity, the game distinguishes two source categories of bonuses: passive and active.

Most passive bonuses come from equipped items (including weapons and shields) and passive abilities. If an effect has no duration and does not need to be turned on or off, it generally is considered a passive bonus. All passive bonuses stack with each other.

Active bonuses come from spells, items, and abilities that must be activated. This includes modal abilities that are toggled on the action bar, such as weapon modals, paladin auras, and a fighter stances. Active bonuses use the highest bonus to a statistic and suppress all equal or lower bonuses.

E.g., if a wizard spell grants +3 to Deflection and a paladin's aura grants +5, the highest active bonus is +5, with the +3 being suppressed. If the same wizard spell also granted a bonus to Dexterity, it would apply unless it was also trumped by a superior Dexterity bonus from another active/modal source.