Critical hit

A critical hit is when an attack deals three times the normal damage (not to be confused with Weapon effectiveness).

Description
A unit's critical hit rate at any given time is most directly influenced by the equipped weapon's "crt" stat. Most weapons raise the chance of scoring a critical hit by only a small amount; however, certain weapons and spells (e.g.: Killer Lance, Killing Edge, Killer Axe, and Luna) have a higher chance of landing a critical hit than most weapons. Even then, the critical hit rate is usually around 35 percent, depending on the class and level of the unit wielding the weapon.

However, there is a possibility that the Critical hit rate can be up to 80% without the use of hacks, depending on the weapon itself, the user and their level, and the Luck between two units. For example, if you use a Swordmaster, with an Iron Sword, the average critical activation rate can go from 10-45. If you give the Swordmaster a Killing Edge, the critical hit rate drastically rises to 45-66. Giving the Swordmaster a Shamshir would increase the rate to 71 or even more.

In most games in the series, when a critical hit activates, the critical-inducing unit performs a flashy set of movements unique to its class. For the most part, melee weapon units spin their weapons rapidly when performing a critical hit; some sword-wielding classes, such as the Swordmaster or Myrmidon, move fast enough to make it appear that they are in more than one place at once and that they disappear momentarily. Magic-using units have a tendency to visibly summon or charge more energy in some ways, such as the Druid tendency to be ringed by their power. In the Tellius series there are two animations for a critical hit: one for a killing blow and the other if it simply causes damage. Also, the airborne units have a Critical Hit animation for battles against ground units and another one against airborne units. In Awakening, when a unit activates a critical, a small cut-in appears of the character (Except for Einherjar characters) along with a critical quote. They will have a specialized attack only for criticals and their weapons will have a pink streak when they attack. Criticals can activate for attacking skills such as Luna, but the attacking animation for that attack skill will prioritize over the critical animation unless the user has activated Ignis.

Factors

 * Class Critical Bonus: Some promoted classes, notably the Swordmaster and Berserker, have a "class critical bonus", which represents a base critical hit rate a member of the class will almost always have in battle. In Fire Emblem: Radiant Dawn, there were five levels of Class Critical Bonuses (Critical +5, Critical +10, Critical +15, Critical +20, Critical +25), represented as skills permanently attached to the Sniper, Marksman, Reaver, Halberdier, Sentinel, Assassin, Myrmidon, Swordmaster and Trueblade classes.
 * Skills: Some skills increase critical hit rate under certain circumstances. For example, the Wrath skill boosts the critical hit rate when the user's HP is at 1/3 or less.
 * Pursuit Critical Coefficient in Fire Emblem: Thracia 776 a limit is placed on critical rate during the first Double Attack hit and then multiplies it during the second hit.
 * Dual Support in Fire Emblem: Awakening boosts the critical activation rate depending on the support rank level that the attacking unit has with their Pair Up partner and any adjacent allies. Critical activation is boosted by 10 at level 4, 15 at level 8, and 20 at level 12.

Critical hit rate calculation
Unit's skill/2 + 5% (If S-rank in Rekka no Ken and The Sacred Stones) + the weapon critical chance + the support bonus (if any) + the class critical bonus (if any) + character's skills (if any) - the enemy's Luck.
 * To calculate a Silencer percent chance of an Assassin, you must halve his Critical Hit percentage (except in Radiant Dawn, where it is half the skill stat).

Hence, it is possible in Fire Emblem: Rekka no Ken for Swordmasters to gain a Critical Hit rate of 100% or more; when it exceeds 100 percent, only the last two digits will be shown. In Fire Emblem: The Sacred Stones the unique Super Trainee classes also can get 100% Critical.

However, the unit must also be able to hit the opponent first. That is, the hit percentage is taken into consideration before the critical percentage. So if a unit has a low chance to hit, but a very high chance to use a critical, (like from the use of the Gamble skill) the unit may miss altogether.
 * While it may be true that the unit must be able to hit the target to get a critical hit in most Fire Emblem games, it is notable that in at least the United States version of Fire Emblem: Rekka no Ken, it is possible to get a critical hit when your hit rate is 0%, making enemy swordmasters, snipers and especially berserkers particularly deadly against units whose survival rely on evasion, as the critical% completely ignores the target's speed.

Critical hits can be completely negated by a unit carrying an Iron Rune (or Hoplon Guard) or with the skill Fortune.

Super Smash Bros. Brawl
Critical Hit (必殺の一撃 Hissatsu no Ichigeki lit. Sure-Killing Blow) is the name of Marth's Final Smash in Brawl. Critical Hit is an extremely fast and powerful Final Smash. After raising his sword, Marth quickly rushes forward, instantly blowing away any enemy that he connects with. A Health Meter appears, graphically similar to the ones in Ankoku Ryū to Hikari no Tsurugi, which rapidly depletes to 0, but is purely for aesthetics. It is arguably one of the most powerful Final Smashes in the game, not just for the 60% damage if it connects, but for the knockback effect, able to KO Bowser, the heaviest character in the game, even when he is at 0% from the opposite edge of a medium sized stage. It can also be launched in the air and he will still propel him straight forward. However on smaller stages, Marth can actually launch himself offscreen using this move and suicide KO himself. Another down side is the long start up time which gives opponents time to telegraph the move and avoid accordingly.