Skills are special abilities which may be used by a player or a Skalari to gain an upper hand in battle. Many player skills are class-locked. The "skills" menu can be toggled using the K key, where you will see skills for your Circle and Major (once you pick one at Lv10).
Unlike Player Skills, most Skalari Skills, especially those used by bosses, are activated once the caster's health falls below a certain percentage.
Player Skills are locked to the class which they use. There are a minimum of 23 active skills available to the player, of which 15 are class specific, 4 are circle-specific and 2 are universal. The number of buff skills are also class specific - Heavy Launchers and Dual Gunners have two buffs, while Crashers, Strikers and Elementalists have five, and Priests have seven.
Most Skalari skills are limited to dungeon and field bosses, but certain Skalari may also possess a few.