Attribute - base score. Used in all cases, sometimes modified by presence of character's profession(s) in relation to the skill check being attempted.

Profession/History - very general; wide variety of skills for a specific application. E.G. clockmaker, brewer, knight, footsoldier;
- each is expressed as a MULTIPLE (or divisor)
- by default, any given profession starts as a x1 multiplier; however even a x1 profession is better than “untrained”, because untrained skills may have a penalty, e.g. untrained swimming may use x10% Strength but minimal profession (Olympic swimmer) uses x100% Strength
- points added to a profession increase the multiple; as a result, a set of skills are increased more than by placing points into an attribute, but the set of these skills is not as wide as those affected by an attribute

Specializations -
- work exactly like Professions, but apply only to a SPECIFIC skill and have an additional perk, which is:
- when used in a combo (i.e. skill stacking), still use x1x(Specialization Multiplier) to determine probability of success, but use x2x(Specialization Multiplier) to determine whether the skill stacking continues despite failure; in other words, the specialization is the same for determining success, but doubled for skill stacking