Weapon Potency runes apply to spellcasting attack rolls and DCs.
Big boost to spellcasters, and brings their average chance of getting the enemy to fail/crit fail up from 40% to 50% for a big portion of their career. A bit powerful at the highest levels, with the +3 on top of Legendary, but honestly, when you're at level 19+, you can already rewrite reality. That, and I tweak up a few spellcaster enemy DCs to compensate at those levels, so they're equally scary, and it all works out.
Weapon Potency runes apply to spellcasting attack rolls and DCs.
Big boost to spellcasters, and brings their average chance of getting the enemy to fail/crit fail up from 40% to 50% for a big portion of their career. A bit powerful at the highest levels, with the +3 on top of Legendary, but honestly, when you're at level 19+, you can already rewrite reality. That, and I tweak up a few spellcaster enemy DCs to compensate at those levels, so they're equally scary, and it all works out.