Most skills in RF Online are not exclusive to one particular class, and most skills can be learned by all classes. Certain classes, however, may be more adept at using some skills than others - that is, certain classes have access to higher level skill tiers – Basic, Expert, and Elite. Some skills are also race dependant. Some skills even require the character to wield a certain type of weapon. Most combat skills are learned automatically as characters level up. Force skills, however, must be purchased and then activated.
Each skill in RF Online has PT, which gains experience the more that the character uses it, and as skills level, their effects may evolve and grow stronger. Each skill also has seven levels of PT, when it reaches maximum level it also has maximum strength and can’t gain any PT anymore; the skill is considered "grand mastered (GM)".
Skill tiers on Close Combat, Long Range, and Force are progressive; you can only unlock new tiers by levelling the preceding skills. Basic skill tiers are the first skills that you can access, by levelling its PT to 30 you can unlock the Expert skill tiers, and by levelling both PT to 50 you can unlock the last tier – Elite skills.