Critical (status)

Critical is a recurring status in the series that makes all of the target's hits deal double damage.

Final Fantasy VII
Cait Sith's Limit Break Lucky Girl allows all party members to deal critical hits every time they attack. The Lucky Girl is a possible combination in Cait Sith's Level 2 Limit Break, Slots, and is executed by lining up three heart symbols.

Crisis Core -Final Fantasy VII-
Critical status can be achieved in various means, either from the Lucky Stars Limit Break executed by lining up three Cissnei portraits during Modulation Phase, by rolling the combination of 6-6-6 in the Digital Mind Wave reels (without a Modulation Phase), or by equipping the Sniper Rifle or Genji Glove accessories.

Final Fantasy X
Rikku's mixes, Hero and Miracle Drink, give either one or all party members the critical status boosting the targets' critical hit rate.

Final Fantasy X-2
Lady Luck learns the ability Critical that makes all of the character's attacks deal critical damage every time. Lady Luck can learn the ability for 160 AP after learning Felicity.