Ability

Ability is the atomic unit of anything a character can do — a spell, a physical combat technique, a gathering action (e.g. netting salmon, harpooning), or a utility action (Jump, Blink). Abilities are what get bound to keybinds/hotbar slots.

Mastery

Each ability tracks its own mastery, which grows from use and increases that ability's power and/or reduces its cost. Mastery is per-ability, not shared with other abilities — improving Jump does not improve Blink, even though both are "utility."

This is the same mastery mechanic Pneuma already uses for spells, generalized to apply to every ability in the game, combat and non-combat alike.

Elemental tagging

Some abilities are tagged with an element (fire, water, air, earth). Using a tagged ability contributes to that element's Affinity and can benefit from it. Most abilities have no elemental tag at all (e.g. Thieving abilities) and never interact with affinity.

Grouping

Abilities are grouped bottom-up into Skills. The grouping is discovered by looking at the actual list of abilities that exist, rather than designed as a fixed taxonomy up front.