Armsthrift (武器節約 Buki setsuyaku lit. Weapon Saver in the Japanese version, Parcimonie in the French version, Accortezza in the Italian version, Ahorro in the Spanish version) is a skill in Fire Emblem Awakening, which, when activated, will not reduce a weapon's durability.
Armsthrift is learned by Mercenaries at Level 1. When the user attacks or retaliates, this skill has a chance to activate. The activation percentage is double that character's luck stat (including bonuses from a weapon, pair up, tonic or rally) thus, if the character's luck is 50 or higher, the weapons they wield will never degrade.
While it is possible to reach 50 or higher Luck without Limit Breaker, Limit Breaker will allow the user to have 50 or more Luck without needing any boosts. Armsthrift goes well with Regalia weapons like Forseti or forged weapons (e.g a forged Brave Sword).
Armsthrift has no effect on staves and weapons that can be "used"; e.g using the Gradivus' healing effect will still cause the weapon to degrade.