Skills

A skill is a specialized collection of abilities that characters develop through use.

Leveling
Skills earn experience points (XP) whenever you perform one of their abilities. 100XP are required to earn the first level in a skill, with a 2% increase for each level. Leveling up your skills unlocks new abilities, archetypes and levels up your attributes.

Experience requirements for the first 10 levels of a skill.

Aptitude
Aptitude represents a character's natural ability with a skill based on core attributes. Each skill has a primary & secondary Attribute that add together to yield its Aptitude. For example, the Swords skill has Dexterity as its primary and Strength as its secondary. If a character's Dexterity is 90 and Strength is 77, the Aptitude will be 128 (90 + 77/2, rounded down).

$$\color{white}Aptitude = PrimaryAttribute + SecondaryAttribute/2$$

Proficiency
Proficiency is the sum of a skill's level and aptitude. Whenever an Ability is invoked, the proficiency of its parent skill is used to determine how well the character will perform. In combat, the attacker initiates with an offensive ability and the defender automatically invokes a defensive ability. Each combatant rolls a D20, the results of which are added to the proficiencies of their abilities' skills, and those totals determine the success of the attack.

$$\color{white}Proficiency = Aptitude + Level$$

Domains
Every skill belongs to a group of related skills called a Domain that also serve as the primary character Archetypes. Combat Skills are grouped into four domains: Warrior, Rogue, Cleric & Mage, while Artisan Skills are grouped into the Builder, Pioneer & Scholar domains. Archetypes, which unlock with Skill Points (SP). When a skill levels up, 2SP are delivered to its Primary Attribute and 1SP to its Secondary Attribute and Domain. For every 20SP, an attribute levels up and domains unlock at 300SP.