Runic Ammunition

Weapon (a bolt, arrow, or piece of sling ammunition), rare

Runic ammunition resembles normal bolts, arrows, or stones that are etched with runes and are magically discordant to spellcasters. Creatures concentrating on a spell when they're hit by a piece of runic ammunition make the resulting Constitution saving throw to maintain concentration with disadvantage.

You have a +1 bonus to attack and damage rolls made with this piece of magic ammunition. Once it hits a target, the ammunition is no longer magical.

The arrow pierced the wizard and emitted a flash of runes and inexplicable glyphs, shredding through their arcane defenses and disrupting the spell they had woven. The wizard's expression darkened in frustration as they turned their attention to the archer, who was already nocking another arrow to their string.