Fallout Shelter SPECIAL

SPECIAL in Fallout Shelter works slightly differently than in other games as Skills do not exist in this game. Each SPECIAL attribute increases dweller efficiency in various rooms, during combat or when performing certain tasks.

Background
Keep in mind that although attributes can only be trained to a maximum of 10, they can still be increased to up to 17 through clothing bonuses. These additional points will not be visible on the dweller's SPECIAL bars but can be checked by tapping/clicking the bars, which brings up a more comprehensive menu that lists any and all bonuses.

Strength
Strength determines:
 * The speed of power production in the power generators and nuclear reactors
 * The speed of crafting in the Weapon workshops for 46 out of 175 weapons
 * Chances at successfully opening lockers in the wasteland

Dwellers can improve their Strength in the weight room.

Perception
Perception determines:
 * The speed of water production in the water treatment and water purification facilities
 * The speed of crafting in the weapon workshops for 55 out of 175 weapons.
 * The speed of the critical hit indicator during quests
 * Chances of finding locations in the wasteland
 * Makes critical hits more accurate. It does so by slowing down the speed at which the critical hit cursor moves in quests.

Dwellers can improve their Perception in the armory.

Endurance
Endurance increases the speed at which the Nuka-Cola bottler creates food and water. Endurance can also increase the speed of crafting in the weapon workshops for 18 out of 175 weapons. It is also the assigned skill for the storage rooms, although it will have no effect on those rooms.

Endurance determines how many hit points dwellers gain as they level up. Dwellers start with 105 health points. They seem to get 2.5 + (END * 0.5) health points each time they level up, so 17 points in Endurance will add 11 hit points per level compared to the minimum of 3 at END 1. This means that a level 50 dweller with 1 Endurance will have 252 hit points when at max level compared to 644 hit points, which a dweller whose endurance was maxed out at 17 from level 1 will have.

To achieve maximum health, a dweller must equip heavy wasteland gear (END +7) at level 1 while already having 10 points in Endurance themselves. At END 11 or more, the dweller becomes immune to the occasional radiation bursts they suffer while exploring the wasteland (note that this does not apply to real-time combat).

These hit points are not retroactive.

Dwellers can improve their Endurance in the fitness room.

Charisma
Charisma determines the effectiveness of radio studios and living rooms by increasing the likelihood of attracting new dwellers for the former and speeding up reproduction for the latter. Additionally, it reduces the time needed to wait for a change after using the barbershop.

It is also used during wasteland exploration to help explorers succeed in encounters with "civilized" persons or groups.

Dwellers can improve their Charisma in the lounge.

Intelligence
Intelligence determines the effectiveness of medbays and science labs. Intelligence also increases the speed of crafting in the Weapon workshops for 13 out of 175 weapons and for 18 outfits in the Outfit workshop.

In the wasteland, intelligent dwellers have better chances at succeeding in encounters with wounded civilized persons (such as injured sheriffs, wounded slaves, etc.), as well as dealing with certain enemy types. Dwellers with high Intelligence also have an increased chance of finding stimpaks and RadAway.

Dwellers can improve their Intelligence in the Classroom.

Agility
Agility determines the effectiveness of food production rooms (diner and garden).

In quests or in the wasteland, it determines how many shots dwellers can fire before the enemy does (effects how quickly a dweller fires their weapon) or how much damage the dweller can avoid when fleeing from hopeless battles.

Dwellers can improve their Agility in the Athletics room.

Luck
Luck determines if a production room also yields caps along with the normal room reward (or extra caps after a successful rush attempt). Luck also affects the chance of rush attempts succeeding.

In the wasteland, it increases the chances of finding items when dwellers go out on quests and explore locations in the wasteland. The higher the Luck, the better the items. During quest combat, it increases the speed at which the critical hit meter fills. In the wasteland, it increases the caps found.

Dwellers can improve their Luck in the Game room.