What is spell save dc?

Spell save DC is a mechanic in Dungeons and Dragons (D&D) that represents the difficulty for creatures to resist your spells. It is determined by the caster's level and spellcasting ability modifier.

When a spell requires a target to make a saving throw, the target must roll a d20 and add their relevant saving throw modifier. If the total is equal to or higher than the caster's spell save DC, the target successfully resists the spell and takes less or no damage, or avoids being affected by the spell's effects altogether.

The spell save DC of a spellcaster is calculated as follows:

Spell save DC = 8 + spellcasting ability modifier + proficiency bonus

The higher the spell save DC, the more likely it is that creatures will fail their saving throws against the spellcaster's spells. Players and dungeon masters can use the spell save DC to determine the outcome of spell effects during gameplay.