[RPG] Are there any ways to raise a character’s saving throw DC past just ability score and proficiency bonus

difficulty-classdnd-5eoptimizationsaving-throwspellcasting

I know that there's Rod of the Pact Keeper for Warlocks specifically, and I know there are items that increase spell attack rolls. Are there any feats, items, or other options in any of the official books that could be used to raise the saving throw DC of a character or is Rod of the Pact Keeper the only item they made for that?

Best Answer

The only other official way to boost your spell DC (without just boosting your ability score) is the Robe of the Archmagi, a crazily powerful legendary item.

The Lore Mastery Arcane Tradition, from Unearthed Arcana, gains the Alchemical Casting ability at 6th level. Among other things, it allows them to sacrifice a 3rd-level spell slot while casting a spell to boost the DC of that spell by 2. Note that as Unearthed Arcana, this is not official, and this particular Unearthed Arcana is widely considered to be extremely overpowered. I don't recommend using it, but I wanted to have something in this answer other than the Robe of the Archmagi.