Mage-Catcher Explosives (Patreon)

Wondrous item, rare

These eight-sided explosives come in a red linen bag. When found, there are 1d3 + 1 explosives in the bag.

You can use an action to throw up to 4 bombs at a point that you can see within 30 feet of you. For each bomb you throw, roll a d8; on a 1, the bomb does nothing. On any other result, the bomb explodes upon impact. If at least 1 bomb explodes, it creates a 10-foot-radius field of magical instability that's centered on the point. Any spell of 3rd level or lower within that area immediately ends.

If multiple bombs explode, the field remains for a number of rounds equal to the amount of bombs that exploded after the first; the field then vanishes at the end of your turn on that round. During that time, any spell of 3rd level or lower that enters the field's area automatically ends.

A creature with the Antimagic Susceptibility trait that's in the field when it appears, starts its turn there, or enters the area for the first time on its turn must succeed on a DC 15 Constitution saving throw or fall unconscious for 1 minute.

Each bomb that explodes is destroyed, unless you roll an 8 on its d8. If you do, the bomb explodes but isn't destroyed, allowing it to be used again at another time.

"Blasted wizards are always making something explode, one way or another. At least these things keep the explosions on our side for once."