Guide:Can You Repair a Badly Damaged Weapon in Tears of the Kingdom?

Yes, you can repair a badly damaged weapon in Tears of the Kingdom by feeding it to a Rock Octorok. They will spit it out, repaired and with an upgraded weapon bonus. This also works with bows and shields.

Limits are that each Rock Octorok will only repair one weapon, bow or shield per Blood Moon cycle, and some items cannot be repaired - amiibo weapons, wooden items and Magic Rods, Scepters & Staves. Items which cannot be repaired, or when a Rock Octorok has already repaired an item in the same blood moon cycle, will simply be spat straight back out at Link, unchanged.

It is advisable to disable any Sage's Vow avatars while attempting to feed a weapon to a Rock Octorok, as they may kill the Rock Octorok before it has gone to work.