Thanks for your time!
The idea is for an an ability for an NPC monster. It’s based on the arcane trickster, but is specifically trained to fight magic users. I’m calling it an arcane hunter, and thinking of making it CR 6-7. However, it could also be a magic item, or a class ability.
For the most part, it’ll have rogue abilities, arcane trickster spellcasting, expertise in arcana and stealth, and two attacks with a rapier.
The ability is called “overcharge spell”: Whenever a spell is cast within 60 feet of the arcane hunter, it can use its reaction to push a bit of extra magic energy into it. This leads to one of four results, based on a d4 roll:
1 - the energy of the spell explodes, the caster and everyone within 5 feet rolls a constitution save. On a failure, take 1d10 force damage per the spell slot of the cast spell. On a success, half damage.
2 - the arcane hunter takes control of the spell energy, directing the spell at whoever they choose, within 20 feet of the caster. (I particularly like this one, because it can be either meaningless or really bad depending on the DM’s timing with the ability).
3 - the spell energy collapses in on itself and has no effect, as if targeted by a counterspell.
4 - the spell functions as normal, but more powerful, as if cast at one spell slot higher.
Recharge on 5-6.
I also asked the blog homebrew-a-la-traumaverse for feedback, and they made the excellent suggestion to have the ability function similar to counterspell. That is, for spells up to 3rd level, the ability functions normally, but for 4th level or higher, the caster of the spell rolls an spellcasting ability check against the arcane hunter’s spell save dc to have their spell function normally. She also suggested I have a successful check makes the spell upcast, but I think I’ll have it only happen if the caster rolls 5 above the spell save dc (which will be 14, I believe).
Hiya! First of all, I'd like to mention that this is a very cool idea and I'm all for it! I definitely think we don't have enough counters to casters in D&D as is (except for counterspell, and maybe confusion effects, which suck for everyone), so I definitely find this a very unique and useful idea.
I like homebrew-a-la-traumaverse's idea of making it similar to counterspell, that fits very well with this idea. However, maybe that makes it a little too similar to counterspell/dispel magic? I definitely think an ability check/saving throw needs to be implemented to make this fair to everyone, though. Instead of making the caster save against the hunter, you could also implement a contested spell ability check, and if the hunter rolls higher than the caster, the hunter's effect takes place.
I'd suggest creating an additional effect on a natural 20 for the hunter (or in case of a contested spell ability check, a natural 1 on the caster's part), like getting to choose one target that the full spell's power is aimed at. It's similar to a roll of 2 on the dice, but I would suggest changing that effect to anyone within 20 feet of the original target, and the natural 20 effect to be anyone within the spell's range, regardless of the original target, if that makes sense. It creates some extra freedom for the hunter to really aim for the PCs who like staying at the back of a fight/out of the way of the other PCs.
Alternatively, you could choose for the hunter to be allowed to pick one of the four effects instead of rolling for it if they roll a natural 20! That has the same effect as above :)
As a fifth and sixth effect, you could implement the following:
5. If the hunter is the target of the spell, it has effect as normal, and the hunter absorbs some of that spell's power. Until the end of the caster's next turn, the hunter has advantage on saving throws to resist the caster's spells (or advantage on all saving throws against spell effects, if you want to beef the hunter up a little).
6. The caster must succeed on a Wisdom saving throw (the DC equals 10 + the spell's level). On a failed save, the caster can't cast that spell again until the end of its next turn.
These are just suggestions! Do with them as you wish, and definitely don't feel obliged to implement any of these suggestions. I hope this was helpful to you :) I'd love to see the finished product, if you're willing to share. Happy brewing!
