Ancestry powers can grant an "ancestry bonus" to an attribute (such as Strength). These follow special rules:

• When adding an ancestry bonus to an ability score, if the bonus plus the base score (plus any other ancestry bonus) is 16 or less, add the full bonus. For example: base 10, ancestry +4, result is 14.
• When the result would exceed 16, add a maximum of +2 per ancestry power. For example, adding three different ancestry powers that each grant +4 to Charisma, with a base of 16, would result in 20 Charisma (16 +2 +2 +2).