Luck

Luck is one of the seven primary statistics in the SPECIAL 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's Adytum can increase Luck permanently by one point via the mysteries of the Tarot. Due to a bug, acquiring a second point is possible.

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.
 * The Hubologists' zeta scans stop the decrease in Luck from the pariah dog's company, subsequently killing the dog will restore the player character's Luck as if it had remained decreased, resulting in a net gain in Luck.

Ways to increase Luck in Fallout Tactics

 * Taking the Gain Luck perk for a permanent increase of 1 Luck.
 * Consuming Voodoo will increase Luck by 3 points for 20 minutes.

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 the 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 4
500px Luck determines the recharge rate of the Critical Hit meter. It can indirectly improve how much caps and ammo one finds through one of two associated Luck perks (see below). It can also give the player a chance to not catch a disease from a molerat bite in Vault 81. Luck can affect the chances of quickly receiving a perfectly preserved pie from the Port-A-Diner (the lower your luck stat, the longer it can take).

Here is a table that shows how many hits one needs to refill the critical meter for different luck values. This does not include the effects of perks or legendary prefixes.

Using a Lucky weapon with the Isodoped companion perk active (250 rads), at 14 Luck you will fill the critical meter in two shots. Without a Lucky weapon you will fill it in two shots at 24 Luck.

Ways to increase Luck

 * Permanent
 * Level (+1)
 * Luck bobblehead (+1)
 * You're SPECIAL! book (+1)
 * Temporary
 * Armor and clothing
 * Greaser jacket and jeans, Atom Cats jacket and jeans, DB Tech varsity uniform, and Mark 4 synth left leg (+2)
 * Undershirt & jeans, battered fedora, chef hat, crumpled fedora, dirty fedora, gray knit cap, Triggerman bowler, yellow slicker hat, Nuka-World geyser shirt & jeans, Bottle and Cappy shirt & jeans, Bottle shirt & jeans, Cappy shirt & jeans, and Nuka-World shirt & jeans (+1)
 * Legendary armor effects
 * Lucky (+2)
 * Unyielding (+3 Health<25%)
 * Chems
 * Day Tripper (+3)
 * X-Cell (+2)
 * Perks
 * Party Girl Party Boy - +3 Luck at rank 3 when drinking alcohol.
 * Magazine
 * Live & Love #5 - +1 Luck when drinking alcohol while having a companion.
 * Settlement objects
 * Slot Machine (+1)
 * Grenades
 * Lucky Rabbit's Foot (+3)

Ways to decrease Luck

 * Temporary
 * Day Tripper addiction (-1)
 * X-Cell Addiction (-2 all stats)
 * Tattered rags (-1)

Fallout 76
Modifies: Looted item condition, recharge rate of critical hits

As with other Fallout 76 SPECIAL attributes, Luck has a maximum of 15 but there are only 49 points split between the 7 attributes

Every time a V.A.T.S. attack is successful, the critical bar increases by an amount dependent on Luck. Once the critical bar fills completely (when the value of the bar equals 100), a critical attack may be executed in V.A.T.S. At a Luck of 1, the critical gain per successful attack (also known as the recharge rate) is 6.5 - this translates to a critical attack being available every 16 successful attacks. Each addition level of luck increases the critical gain by 1.5. At the maximum Luck of 15, the critical gain per successful attack is 27.5 - this translates to a critical attack being available every 4 successful attacks.

Ways to increase Luck
Note that all stat boosts in Fallout 76 are temporary.
 * Bobblehead: Luck (+2 for 1 hour or 2 hours with Curator)
 * Armor and clothing:
 * "Vault suit" underarmor with a treated lining mod (+1)
 * "Casual" or "Vault suit" underarmor with a resistant lining mod (+1)
 * "Casual" underarmor with a protective lining mod (+1)
 * "Vault suit" underarmor with a protective lining mod (+2)
 * "Casual" or "Raider" underarmor with a shielded lining mod (+1)
 * "Vault suit" underarmor with a shielded lining mod (+2)
 * Legendary Effects:
 * Luck (+1)
 * Magazines:
 * Live and Love 5 (+2 while under the influence of alcohol)
 * Mutations:
 * Herd Mentality (+2 if grouped, -2 if solo)
 * Perks:
 * Happy-Go-Lucky (+2 or +3 while under the influence of alcohol)
 * Consumables:
 * Food:
 * Appalachili (+2)
 * Awesome opossum bacon (+2)
 * Chally's feed (+1)
 * Charred scorchbeast liver (+3)
 * Chew stick (+1)
 * Iguana on a stick (+1)
 * Scorchbeast mixed meat stew (+1)
 * Seared venison with berries (+3)
 * Seasoned rabbit skewers (Fallout 76) (+1)
 * Chems:
 * Day Tripper (+3)
 * X-Cell (+2)
 * CAMP items:
 * Fortune teller machine (+2)
 * West Virginia Slot Machine (+2)

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 and the chance of getting caps when harvesting power/food/water from a room.

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

By equipping outfits that raises Luck.
 * Temporary

Fallout: The Board Game
Unlike other games, Luck is not treated as a variable ranging from 1 to 10, but instead as a token that can be obtained at the start or when leveling up. A player character with the Luck token gets free rerolls during certain tests, as well as during fights if equipped with a Luck-based weapon.

The Vault Dweller player character always begins the game with Luck. Any player character wearing the singed duster gains one hit during a Luck test. During any Luck test or fight, Day Tripper can be used to gain one free hit. While not a Luck-based weapon, if a player character goes into a fight with the Fat Man, they must succeed at a Luck test or be unable to perform any rerolls during the fight.

Perks

 * Fortune Finder
 * Grim Reaper Sprint

Weapons

 * Plasma gun
 * Super sledge