The Wunderwaffe DG-2 is an intricate, arcane firearm crafted with advanced alchemical and magical technology. It has a sleek, metallic finish adorned with glowing runes and a distinct, eerie humming sound when charged. It also has three holes on the side to add the ammunition into.

Special Properties:

• Charge Mechanism: The DG-2 has a rechargeable power source. After every 3 shots, the weapon must be recharged for 1 minute, during which it cannot be used. If the DG-2 is fired without fully charging, it only deals 1d10 lightning damage instead of 2d10, and the recharging phase resets with every non-fully charged shot.

• Chain Reaction: On a hit, if the attack roll is a natural 20, the target takes an additional 2d10 lightning damage and must succeed on a DC 15 Constitution saving throw or be stunned until the end of its next turn.

• Overload: As a bonus action, you can overload the weapon, firing a powerful burst. This attack targets all creatures in a 15-foot cone. Each creature must make a DC 15 Dexterity saving throw, taking 4d10 lightning damage on a failed save or half as much damage on a successful one. After using this feature, the weapon must be recharged for 5 minutes.

Ammunition:

The Wunderwaffe DG-2 uses special magical cartridges, which can be crafted with alchemical components worth 25 gp each. A successful Intelligence (Arcana) check (DC 15) can create 1d4 rounds of ammunition during a long rest.

It’s up to you to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

Notes: Spellcaster or Artificer, Range, Two-Handed, Ammunition (Firearms), Reload, Slow