Primary Ability

PCs choose one Ability Score to be their Primary Ability as part of their Background.

You add the result of your Expertise Die to Checks (d20 rolls) made with your primary ability.

Expertise Die

Your expertise die progresses as you Level according to this table:

Level	Die	Optional Static Bonus Rule
0	None	+0
1-4	d4	+2
5-9	d6	+3
10+	d8	+4

The result of the expertise die does not impact if a roll is a Critical Success or Critical Failure.

Minor Boons

If beneficial circumstances arise for a Check using a PC's primary ability, but not enough for d20 Advantage, the GM may grant the PC Advantage on their Expertise Die.