I would point out that there's no RAW methods of losing a limb (it only happens due to plot device) so you won't introduce any balance issues by making it possible to restore limbs with a lower level spell, such as Greater Restoration, it just limits your ability to use lost limbs as plot devices in the future.
It should be fairly easy to get the gnomes in Gnomengarde to construct him something. Fibblestib and Dabbledaub could tinker up a hand if they can tinker up a Sanity Ray. (He’d just be extra susceptible to the Heat Metal spell for as long as he uses the metal hand.) In exchange for the hand, they could require the party to clear the Tower of Storms location. A nasty half-orc priest of Talos (Moesko) stole their enlarging ray. “We were testing it out on boulders near the road. He happened by, and when he found out what we had, he cast a Thunderwave. While we were on the ground he took the ray and ran off.” They want the party to track him down and get the ray back. They know there’s a temple to Talos on the coast. Try looking there. Moesko used the ray to enlarge the grean glowing heart-beacon in the Tower. It can be recovered in the room where the party finds and fights him. If they bring the ray back, they’ll build him a custom hand as an even trade.
So, all you need to invent to get yourself out of this is an Enlarging Ray that can be found and returned from a location that needed a better adventure hook to be used anyway.
Wondrous Item, common (requires attunement by a creature missing some or all of a limb)
This artificial limb replaces a hand, arm, foot, leg, or similar appendage that was lost or removed. While the prosthetic is attached and attuned to you, it functions identically to the body part it is replacing. You can detach or reattach it as an action, and it can’t be removed by anyone else.
If you have multiple prosthetic limbs, they count as a single magic item with regard to the number of magic items you can attune to.
Does he have to get HIS hand back? The first thing I think of is The Hand of Vecna. Which you should NOT give him but you could whip up some kind of magical hand to give him that is much less powerful hand. They are in a dungeon and open up a tomb but all that’s in it is a perfectly preserved hand.
The Helping Hand: lets you cast the guidance cantrip once per day (or maybe at will) But the downside is it’s like a bugbear hand or something that doesn’t match his body at all.
I would point out that there's no RAW methods of losing a limb (it only happens due to plot device) so you won't introduce any balance issues by making it possible to restore limbs with a lower level spell, such as Greater Restoration, it just limits your ability to use lost limbs as plot devices in the future.
Those are all very good ideas! I thought about the gnomes being able to make him a new one, but that’s a much better quest than what I was thinking. And my party hasn’t gone to the tower of storms yet, so that works really well. All of those options would be a nice solution.
And now that I think about it, I could present him multiple options, maybe through rumors of different people/places that could help, and then let him choose how to proceed.
I would point out that there's no RAW methods of losing a limb (it only happens due to plot device) so you won't introduce any balance issues by making it possible to restore limbs with a lower level spell, such as Greater Restoration, it just limits your ability to use lost limbs as plot devices in the future.
Those are all very good ideas! I thought about the gnomes being able to make him a new one, but that’s a much better quest than what I was thinking. And my party hasn’t gone to the tower of storms yet, so that works really well. All of those options would be a nice solution.
And now that I think about it, I could present him multiple options, maybe through rumors of different people/places that could help, and then let him choose how to proceed.
And an excellent reason for handing out GM's Inspiration (considering it a flaw) whenever his lack of a hand causes him problems (e.g. climbing).