What a level of skill means

I consider (under skills and powers style) that a base level of proficiency is equivalent to journeyman skill. A professional will have a higher level of skill In general, a character with a score of 6 is a journeyman, 10 is expert, 15 is highly skilled, 20 is sage-level, 25 is astonding, 30 is legendary.

Sub-skill concentration

A character may specialise in a particular proficiency, gaining +2 to a selected "sub-skill", and -2 to all others. This may be done twice per proficiency.

For example, Zim Skyfarer is an aeronautical gnomish engineer. After discussing the matter with the player, the DM decides that engineering is divided into civil, mechanical and aeronautical fields. Zim specialises in aeronautical engineering, gaining +2 to his score in this area. If he deals with civil or mechincal forms of engineering, is skill is two points worse than normal (4 points worse than his aeronautical). He he chose to, he could further specialise in the field of aeronautics, perhaps in passenger craft. This would -4 to civil or mechanical, +2 to aeronautical, and +4 to passenger aircraft.

Glenn Butcher / knight