Jury Rigging

 is a perk in Fallout: New Vegas and has not appeared in any other of the games in the Fallout series

Effects
"You possess the amazing ability to repair any item using a roughly similar item. Fix a trail carbine with a hunting rifle, a plasma defender with a laser pistol, or even power armor with metal armor. How does it work? Nobody knows…except you."

The perk basically allows you to repair items based on category, instead of type. For example, you can repair the rare Ranger Sequoia with the common .357 magnum revolver. Same goes for armor and clothing as well. Essentially, this perk is very useful by allowing you to use more common items to repair other, more uncommon items.

Many consider the greatest asset of this perk to be the ability to repair and maintain rare and hard to obtain items using simple mundane ones. Ranger Veteran Armor can be repaired using any medium-class armor, and guns that use similar ammunition types can repair each other (such as the Assault Carbine and the Light Machine Gun). However some weapons can be repaired beyond just their own gun and ammo type, hunting rifles for instance, can be used to repair lever-action shotguns and hunting shotguns.

Word of warning though, that once this perk is taken, unique and modded weapons WILL show up on your repair screen just like they did in Fallout 3, since these unique (or modded) items are nonetheless in the same category as their base items. As such, you are advised to be cautious as to what you're trying to repair, with which item as ingredient.

So far, there are at least 10 categories of weapons that the perk will enable repairing each other within category; Unarmed, One handed melee, Two handed melee, One handed guns, Automatic Rifles, Manual loading rifles / Shotguns, 2 lines of Energy weapons, Heavy weapons, Explosive throwers. Likewise, clothings can be used to repair each other within their category (Light, Medium, Heavy). Headwears are even less restricted; entire headwears - including apparels like eyeglasses - can be used to repair each other.

Short list of items that can be repaired with other, similar items, includes, but is not limited to:

Weapons:

Ripper - Hatchet (One handed melee)

Chainsaw - Baseball Bat (Two handed melee)

Laser RCW - Plasma Rifle (Energy Weapons)

Trail Carbine - Hunting Rifle (Manual loading rifles / Shotguns)

Plasma Defender - Laser Pistol (Energy Weapons)

Ranger Sequoia - .357 Magnum Revolver (One handed guns)

Sniper Rifle - .22 silenced SMG (Automatic Rifles)

10mm SMG - Sawed-off shotgun (One handed guns)

Hunting Shotgun - Vermint Rifle (Manual loading rifles / Shotguns)

Armor:

Power Armor - Metal Armor (Heavy Armor)

Combat Armor Helmet reinforced MkII - Sunglasses (Headwear)