Nightspike

Weapon (light crossbow), uncommon

This light crossbow uses blowgun needles for ammunition, instead of traditional crossbow bolts. This weapon uses 2d6 for its damage dice, instead of its normal damage die (you still add your Dexterity modifier to the damage rolls).

If a ranged attack with this weapon reduces a creature to 0 hit points, you can choose to knock it out. When you do, the creature falls unconscious and is stable.

Whenever you hit a creature with a ranged attack with the weapon and roll the same number on both of the weapon's damage dice, the target must also make a DC 13 Constitution saving throw. The target automatically succeeds on this saving throw if it is immune to poison.

On a failed save, the creature becomes indifferent about anything it was hostile toward until the end of its next turn, at which point it must then make another DC 13 Constitution saving throw. On a failed save, the creature falls asleep, becoming unconscious for 1 minute. The sleeping creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. The effect ends early if the creature takes any damage.