Fallout Shelter SPECIAL

Overview
Unlike in other Fallout games, the SPECIAL statistics are not associated with any skills or perks, but merely dictate the efficiency in regards to operating rooms, exploring, and questing. The statistic bar of a dweller (accessible by tapping the dweller) only goes up to 10, but the game will recognize statistics that go beyond 10 through the use of different clothing; through this method, the maximum a SPECIAL statistic can be is 17.

Strength
Strength is primarily used to increase the speed and efficiency at which dwellers produce power in rooms, and can be increased by assigning a dweller to a weight room. When exploring, a higher Strength improves a dweller's chance of breaking open locked containers and doors, as well as increases damage dealt to enemies.

Perception
Perception is primarily used to increase the speed and efficiency at which dwellers produce water in rooms, and can be increased by assigning a dweller to an armory. When exploring, a higher Perception improves a dweller's chance of finding better and rarer items, as well as uncovering random encounter locations. When on a quest, Perception also slows down the rate at which the critical hit meter will oscillate, giving a better chance at achieving a higher damage multiplier.

Endurance
Endurance is primarily used to increase the speed and efficiency at which water and food are produced at a Nuka-Cola bottler room, and can be increased in a fitness room. The statistic also determines a dweller's happiness when they are placed in a storage room, although it does not increase the amount of storage space provided.

Endurance is also responsible to increasing a dweller's hit points each time they level up; these hit points are not retroactively applied should a dweller get a higher Endurance. Furthermore, Endurance determines how much damage a dweller takes when exploring as well as their resistance to accumulating radiation. Should a dweller's Endurance be 11 or higher, the amount of radiation accumulated will actually become negative and not affect the dweller.

Charisma
Charisma is primarily used to increase the speed at which dwellers reproduce in living quarters and attract new vault dwellers with radio studios; it can be increased at a lounge. When exploring, Charisma increases the chances of meeting friendly wastelanders who can give dwellers supplies.

Intelligence
Intelligence is primarily used to increase the speed at which stimpaks and RadAway are produced by medbays and science labs, respectively. It can be trained in a classroom. When exploring, Intelligence increases the chances of a dweller being able to help other wastelanders (such as wounded slaves, etc.) as well as deal with certain enemies quicker (such as shooting for a mirelurk's face).

Agility
Agility is primarily used to increase the speed and efficiency at which dwellers produce food in rooms, and can be increased in an athletics room. When questing and exploring, Agility determines how quickly a dweller returns fire when in combat and when they should run (resulting in less damage) should an enemy in the wasteland be too tough for them.

Luck
Luck is primarily used in determine the success rate of rushing the production of a room; furthermore, Luck plays a role in randomly receiving caps after collecting resources, and receiving extra caps after a successful rush attempt. Luck can be increased in a game room.

When exploring, Luck increases the number of caps dwellers find in the wasteland, as well as increasing the rate at which they find caps in the first place; it also increases their chances of finding rare items. During quests, Luck determines how quickly the critical hit gauge increases.