Found in an ancient and forgotten facility where the doors know you’re there and slide open on their own, perhaps behind one that had to be pried open by the barbarian. Or maybe its captured from a bounty hunter who came from the stars for the party’s heads.
A jet pack is a technological source of flight and understanding it can be handled using the suggested rules on Page 268 of the DMG (4 checks), but consider having abysmal failures result in 2d6 falling damage from attempting the fly using it.
This particular design has been thought out to keep the user’s hands free during flight, using sophisticated leg controls that become second nature with use (apply your Proficiency bonus after 2 hours of use without Piloting proficiency). A character using a jetpack expends their movement to make a Dexterity (Piloting) check. The maneuver they are attempting determines the DC:
- DC 0: Hover in place.
- DC 4: Up to 40 feet in a straight line OR 90 degree rotation in place.
- DC 8: Up to 80 feet in a straight line OR 40 feet with a single turn OR 180 degree rotation in place.
- DC 12: Up to 120 feet in a straight line or 80 feet with a single turn or 40 feet with two turns.
Failure results in plummeting toward the ground by the number of feet you attempted to move, minimum 40 feet, taking appropriate falling damage if a surface intervenes as if having fallen the full distance even if the surface came sooner.
The jet pack’s fuel tanks can hold up to 30 minutes of flight fuel which you might be able to refuel in the facility where it was found. Alternatively, a creation spell cast by someone who has succeeded on 4 checks to understand the fuel can create appropriate fuel lasting 1 day (Vegetable Matter) if unused.
I couldn’t believe a jet pack was pictured in the DMG but not described at all. Alas, such technology did not find a place in Sentient Skies.