All Actions Require AC
Normal attacks, artes, and continuous quick-steps all require 1 AC. (Note that the first quick-step is free, but each subsequent one costs AC. Also Linked Artes do not consume AC.) AC immediately refills to its max when you stop taking any actions, and you can guard or free run while it regenerates. AC does not refill while in mid-air or you’re being attacked. All characters begin with 3 AC. Weapons, skills, and accessories can all be used to increase max AC.
Using AC Bonuses
Fulfilling certain conditions in battle can temporarily increase your AC. Earning critical hits, the skill Momentary Gain, and the skill Power Charge can each increase your AC by 3 each. However, AC earned from bonuses does not replenish automatically like your standard AC.