In Service of Mrs. Jones
Almost everything in the game is rated according to what’s called “The Ladder” (see below).
To give an example of how you might think of using the ladder, most people are between Good (+ 3) and Average (+ 1) at the things they do for a living. PCs are what we might call “exceptional”. They push the boundaries of what normal people can do, and tend to be Great (+ 4) or Superb (+ 5) at whatever their central focus is. It is completely possible for you to be an Epic (+ 7) lunch lady or Legendary (+ 8) cop, but that doesn’t come until higher levels.
So when you make a roll to jump over a log using your Athletics skill, if you’re a Fair athlete, you start with + 2 from Athletics and roll to see what your total is.