Counterspell Hacks for More Interesting Worldbuilding

A few ideas for hacking Counterspell in D&D. I can imagine more extreme alterations and I'm sure there are games that have experimented more broadly, but I'm keeping this post relatively close to the rules as written.

You Can Counter Any Spell You Know

D&D has occasionally tried to model knowledge of the spell as part of the countering process, but it usually just adds another annoying ability check to a process that is already disrupting the normal flow of gameplay. Instead, just say that no roll is required if you know the spell that you're trying to counter. You just counter it automatically.

This more closely models a lot of Appendix N fiction that inspired D&D. If you try to attack a wizard with a spell they have already mastered, they’re going to laugh in your face. This gives wizards a much more concrete reason to hoard knowledge and keep spells to themselves, to ensure that they are the only ones who know a particularly useful spell. 

This also incentivizes PCs to learn about their opponents before fighting them. Knowing a wizard’s spell list in advance is a big part of fighting them; by avoiding casting spells they know and prioritizing spells they don’t. 

Many D&D systems offer spell research systems, but my experience is that few players take an interest in them. The official spells in the book are too enticing, and the idea of creating new spells is too open-ended and abstract for a lot of players.

But what if we're using this option? And the PC is trying to fight an evil wizard who knows most of the same spells as them? Suddenly, coming up with their own new spells is a much more appealing option for prevailing. 

You Can Counter a Spell of a Lower Level

D&D 5E.2014 already partially models this idea by allowing Counterspell to automatically counter spells of the same level or lower, plus a roll when Counterspell is used to counter a higher-level spell. We could simply remove the option to roll and say that Counterspell either works automatically, or not at all. In other words, Counterspell cast normally can counter a first- through third-level spell. Want to counter a higher-level spell? You have to use a slot of that level or higher to do so.

This obviously nerfs Counterspell, but I don’t have a problem with that. It’s already one of the most powerful spells in the game. What’s good for the magic goose is also good for the gandermancer, so this change would also help players frustrated at seeing their high-level spells counter-spammed by enemy wizards.

You just know this guy is going to Counterspell you. From Ena: Dream BBQ

You Can Counter a Spell of the Opposing School

I’ve written before that the schools of magic are an underutilized source of worldbuilding in D&D. What if those rivalries define what a wizard can counter? This gives some mechanical teeth to an interesting worldbuilding feature.

If limiting Counterspell to only these rivalries makes the spell too niche, we could simply say that on top of the normal language of Counterspell, countering a rival school's spell counts as if it was done with a slot two levels higher than what was actually used.

Combine All Three

You could create a system where the baseline is that a third-level slot can counter a first level spell, but if the caster knows the spell, that reduces the cost by one, so that they could use a second-level slot. Same thing if they are a member of an opposed school. But countering a spell of one’s own school would add a level, making it more difficult. 

I don’t really recommend this, because it’s crossing the line from “reasonable homebrew” to “oops this is a new magic system.” But go where your heart takes you, wizard.