In revisiting my thoughts on skills for B&BM this is how I (currently) am going to play test them. There are 3 basic skill levels: Untrained, Trained and Expert. In a nutshell:
Untrained-Anyone can try any skill but they start with a base of 4 dice in the attempt. So Jimmy the Knucklehead tries to throw a knife for the first time ever--4/DX in the attempt.
Trained-this is a skill you have "bought" and become trained in you roll 3 dice when attempting to use this skill. Jimmy the Knucklehead is a trained to pick lock, he rolls 3/DX.
Expert-this is a skill you "bought" twice to gain superior training and to become an expert in it. The base test is still a 3 dice test like a trained skill but you add a fourth "expert" die to the attempt. For the test only use the 3 lowest dice rolled as a sum, the player dismisses the highest die rolled of the 4 and does not count it in the attempt.
Jimmy the Knucklehead tries to charm the ladies, and everyone knows Jimmy is an expert in sweet talking the ladies! So he roll 3/IQ+1 Expert die getting a result of 3,3,4,5. The highest die rolled (5) is ignored and Jimmy's total is (3+3+4) a 10! Too bad Jimmy's IQ is 8...what a knucklehead
Note, The referee, based on difficulty, may still add a die or DRM to any attempt made.