Magic Mishap Items (5e)

From the introduction: Not every magic item is the pride and joy of the artificer who crafted it. Of course, some magic items aren’t made intentionally to begin with. These are the weapons bathed in the blood of elder dragon’s last heartbeat, staves held by mad wizards when they perform the ritual to attempt to achieve godhood, cloaks caught in the explosion when a crashing spaceship hits a medieval school of alchemy, or rings struck by a bolt of pure chaos when the wildmage breaks the lich’s soulvault. Often these accidental magic items take well-recognized and familiar forms—swords of dragonslaying and staves of might—but sometimes weirder items result from such accidental imbuements.