Acid Bomb

As an action, a character can throw a glass vial with acidic mist at a point up to 60 feet away.

Each creature within 15 feet of an exploding Acid Bomb must make a DC 15 Dexterity saving throw, taking 4d6 acid damage on a failed save, or half as much damage on a successful one.
On a failed save, the creatures AC and attack rolls with physical weapons are reduced by 3 for 1d4 rounds.
Switching to another weapon or changing armor lifts that condition.
Natural Armor and Spells like Shield or Mage Armor are unaffected by this effect.