Luck

Luck is one of the seven primary statistics in the SPECIAL character system.

Fallout, Fallout 2, Fallout Tactics
In Fallout, Luck primarily affects the chances with the virtual dice of the game: a high Luck increases the likelihood to succeed a roll, while the opposite is also true. Luck also affects the chance to score a critical hit on a target, with the standard being that the Critical Chance is equal to the subject's Luck (keep in mind, standard means without perks, traits, or aimed shots). It also determines the initial level of the Gambling skill.

Ways to increase Luck in Fallout

 * Chuck in the Boneyard - Adytum can increase Luck permanently by one point via the mysteries of the Tarot.

Ways to increase Luck in Fallout 2

 * The Hubologists can be visited to gain a Luck bonus. Only one bonus can be gained, though they have two bases, one in the NCR and one in San Francisco. The NCR bonus can either boost Luck by 2 or reduce it by one, and the San Francisco base can either boost Luck and Intelligence by 1, or reduce Luck by 1.
 * Taking the Gain Luck perk for an increase of 1 Luck.
 * With the Hubologist zeta scans, it will stop the decrease in Luck from the Pariah Dog's company. Subsequently killing the pariah dog will then restore Luck as if it had been decreased, resulting in a gain in Luck.

Fallout 3
Modifies: All Skills and Critical Chance. Unlike other S.P.E.C.I.A.L. scores, Luck has no specific skills associated with it. Instead, every two points of Luck adds one point to all skills. Having a high Luck will also improve your Critical Chance with all weapons.

Ways to increase Luck

 * Permanent
 * Bobblehead - Luck (+1)
 * Intense Training perk (+1)
 * No Weaknesses perk (will raise base to 5, if below 5)
 * Almost Perfect perk (will raise base to 9, if below 9)
 * Temporary
 * The Lucky 8-ball increases Luck by 1 as long as it is in the player's inventory.
 * Armor and clothing
 * Modified utility jumpsuit, naughty nightwear, Ranger battle armor (+1)
 * Lucky shades, Three Dog's headwear (+1)
 * Ashur's power armor, tribal power armor (+1)

Fallout: New Vegas
Luck functions in the same manner as Fallout 3. It raises the value of every skill (see chart at bottom of page) and affects Critical Chance. It also improves the odds of winning at any casino game; the higher the Luck, the more likely favorable outcomes on bets will be. If having won a casino bet through the influence of Luck, the "You feel lucky" message is displayed. A Luck of 6 will begin to influence Roulette and Slot machines, though rarely. A Luck of 7 is required to win with any regularity or to begin to influence Blackjack outcomes.

Ways to increase Luck

 * Permanent
 * Luck Implant available at the New Vegas medical clinic (+1)
 * Intense Training perk (+1)
 * Completing the quest The Apocalypse or The End will allow raising any one primary statistic by 1.
 * Temporary
 * Armor and clothing.
 * Naughty nightwear (+1)
 * Lucky shades (+1) (Added to the game after the 1.2 patch.)
 * "Blackjack" variant of the Courier duster (+1)
 * Perks
 * Meat of Champions perk (+1 for 60 seconds after eating a corpse.)
 * Just Lucky I'm Alive (+4 after finishing a fight with less than 25% health)
 * Traits
 * Claustrophobia (+1 while outdoors, but -1 indoors)
 * Early Bird (+2 between 6am and 12pm, but -1 between 6pm and 6am)

Fallout 4
Modifies: Critical Hit, Critical Meter, Chance to find Caps/Ammo

Ways to Increase Luck

 * Permanent
 * Level (+1)
 * Luck bobblehead (+1)
 * You're SPECIAL! book (+1)
 * Temporary
 * Armor and clothing
 * Greaser jacket and jeans, DB tech varsity uniform, Mark 4 synth left leg (+2)
 * Undershirt & jeans, Battered fedora, Crumpled fedora, Dirty fedora, Gray knit cap, Triggerman bowler, Tattered rags, Yellow slicker hat (+1)
 * Legendary armor effects
 * Lucky (+2)
 * Chems
 * Day Tripper (+3)
 * X-cell (+2)

Luck and critical meter
Here is a table that shows you how many hits you need to refill your critical meter for different luck values. (perks and lagendary prefixes are not calculated)

Fallout Shelter
Modifies: Increases the chance of a Rush being successful, the amount of power/food/water obtained from rooms, the chance of finding items when exploring, the chance of getting caps when harvesting power/food/water from a room, and the amount of caps obtained when leveling up a dweller.

Ways to increase Luck
By training Luck in game room.
 * Permanent

By equipping outfits that raises Luck.
 * Temporary