Repair

Repair is a Fallout, Fallout 2, Fallout Tactics, and Fallout 3 skill. In Van Buren it was renamed to Mechanics.

The practical application of the Science skill. The fixing of broken equipment, machinery and electronics.

Fallout, Fallout 2 and Fallout Tactics
Initial Level: Starting Repair skill is equal to 20% + (1% x Intelligence). Average characters will have a 25% skill.

Fallout 3
Initial Level: Starting Repair skill is equal to 2 + (2 x Intelligence) + Luck/2 (rounded up). Average starting characters (Int 6, Lck 5) will have a Repair skill of 17%.

Repair can be used to fix damaged equipment, this is done by having 2 of the same armor or weapon, the user sacrifices parts from one item to bring up the condition of the other. Repair is also the skill used to make Custom equipment.

As the Repair skill improves two noticeable effects occur. First, the condition of the equipment can be brought up to the Repair skill - a 70 Repair skill allows items to be repaired up to 70%. The second benefit is that repairs become more efficient. This has a dramatic effect later in the game, as some weapons can more than double in damage when repaired to maximum condition. In other words...
 * Damage will increase as the repair state increases. Higher repair doesn't increase damage by itself, but it allows you to more fully-repair weapons, and that is what increases their damage.
 * The higher your repair skill, the more repair bang you'll get from the items you use as spare parts. For example, you have one Minigun at 60% and you have another Minigun that's at 10%.  With a low Repair skill, you might get a 5% improvement out of the 10% Minigun.  With high Repair, that 10% Minigun will yield a 15%-20% improvement.

It is useful to get this skill to at least 50, making it capable of replacing some of the early repair merchants for common weapons.

Repair is also used to disarm traps (non-explosive traps like tripwires and pressure plates).

In addition to assigning Skill Points at Level up, Repair can be permanently raised by taking the Gun Nut Perk, finding the Repair Bobblehead (behind an Average lock in Evan King's house in Arefu), or reading Dean's Electronics. Repair can be temporarily raised by wearing a Vault 101 Utility Jumpsuit (+5) or by taking Mentats (only works if Intelligence is not already at 10).

Repair in Quests

 * A Repair skill of 30 is necessary to fix the water valves in Megaton, which is necessary for the quest Walter gives you (to fix the valves) and the only way you can turn in Scrap Metal to him for caps and exp.
 * Repair is needed to repair the elevator in the Statesman Hotel, which provides an expedited route through the quest.