Pathfinder's Rise of the Rolemaster
Rolemaster Basics and Definitions
A characters realm is basically where the character’s specialization and development options are focused. There are 3 realms of power, Channeling, Essence, and Mentalism, as well as the realm of Arms. The realms of power are all spellcasting realms and each draws power for their spells from a different source, with attendant pros and cons. Those specializing in one of the realms of power generally are less competent in the realm of Arms, which is the realm of the mundane physical world.
There are certain Professions that split their specialization between two different realms, with an attendant penalty to their mastery of either realm. Professions that specialize in two realms of power are called hybrids while professions that mix a realm of power with the realm of Arms are called semis, terms that are short for hybrid-casters and semi-casters, respectively; the remaining terms in the casting hierarchy would be pure casters and non-casters.
Skills are the core of the Rolemaster system. Basically everything a character does will be governed by their proficiency in a skill. Any character can learn any skill regardless of Profession and their proficiency in a given skill is largely a matter of natural aptitude and how much effort the character puts into developing that skill (as reflected by Development Points).
Skill Rolls are how success or failure is determined for basically everything a character does.
Stats are the base mental and physical attributes of a character.