Mastery

 Mastery of a specific weapon, craft, skill, etc. It will allow you to become better in said area. When you master something, you go +1 in rank in said area.

Mastery rankings;

Foolish; -3 rolls

Foolish; unknowing the said area.

Untrained; -2 rolls

Untrained; knows what it is but no real knowledge in this field.

Simple training; -1 rolls

Simple training; some basic knowledge but not much, some simple training excercises

Trained; 0

Trained; fair enough been training a couple months by now.

Advance; +1 rolls.

Advance; better than the average

Journeyman; +2 rolls

Journeyman; beyond others this could be considered a part of your life.

Expert; +3 rolls

Expert; a cut above the rest you've poured your blood, sweat and tears into this!

Master; +4 rolls

Master; you could teach the most foolish fool in your field.

Master +1; +5 rolls

Master +1; you question your full knowledge and know there is so much more to learn.

Etc.

You can focus on more niche areas to master; you don't have to master the broad skill such as cooking; you could focus on cooking meat and master cooking meat and gain +1 modifier in the said area you're more niche in, however, outside the niche area, you don't gain a bonus too.

Your number of mastery is based on your WIS score.

Your mastery cannot go beyond your player level.