How Spell DC Really Works in Pathfinder RPG

Tabletop Games are one step above playground games. The thing that separates them is the big book of R-U-L-E-S that gives us some structure for our game.

There is one rule though that is more squirrely than most, but is important if we don’t want a game to turn into “I got you!” “Nuh-uh, I got you first!”

Spell Difficulty Class, Spell DC, or a spell saving throw, is a method of gauging how difficult a spell’s effects are to actually resist. 

What is Spell DC in Pathfinder?

A Spell DC is something intrinsic to every spell in the game. 99 percent of the time though it is the number a target of a spell must meet with a saving throw in order to avoid, negate, or resist some or all of a spell’s specific effects.

How Do I Calculate Spell DC?

We must use MATH! The Best Arithromancers in the Labs have been at work on this relatively simple formula to Find the Spell DC:

10 + spell level + your caster ability modifier

We start out with the flat 10, followed by the level of the spell in question(0 t0 9 on the Vancian Magic Scale), then Caster Ability Modifier. 

The Caster Ability Modifier is dependent on the Spell Casting Class:

Bards, Paladins, and Sorcerers use Charisma

Clerics, Druids, and Rangers use Wisdom

Wizards are the odd men out and use Intelligence.

Let’s look at some examples!

Example 1

Fae’bel Silverclaw is a Bard, and she is currently desperately attempting to get her husband, fellow adventurer Arisada, to keep from spilling the beans about the treasure horde they got from a dragon fight.

She decides to use the 1st-level Bard Spell Aphasia to tie his tongue. She has a 14 Charisma score, so her Caster Ability Modifier is a +2.

Let’s look at the spell Aphasia

“You render the target unable to understand any language, including spoken language, written language, sign language, gestures attempting to mimic a crude language, or even truespeech and telepathy. The affected creature is unable to communicate, use command words, cast spells with verbal components, or use any other abilities that requires language.

At the end of each of its turns, the subject can attempt a new saving throw to end the effect.”

A Will Save is the required saving throw for Aphasia. In this case Fae’s Spell DC is 13. 10 + 1 (spell level) + 2 (her charisma modifier). So therefore her husband now has to make a will save against a DC 13 to be able to talk!

Example 2

Stephen is a Cleric locked in a pitched battle with a Demon, but he has a trick up his sleeve. He’s prepped Dismissal:

“This spell forces an extraplanar creature back to its proper plane if it fails a Will save. If the spell is successful, the creature is instantly whisked away, but there is a 20% chance of actually sending the subject to a plane other than its own.”

Stephen has a Wisdom of 16, meaning his caster ability modifier is a +3. Dismissal is also a level 4 Cleric Spell. 10 + 4 (spell level) + 3 (his wisdom modifier).

This makes his Spell DC 17. That Demon better hope he can beat a DC 17 will save, or he is going packing right back home.

3) Amie Gilrose is a Wizard in a tavern with her young friends and her friends are getting into all kinds of shenanigans. Amie wants to crash for the night, but Dana is still drinking. There is only one thing that can solve this: Amie has a Sleep spell:

“A sleep spell causes a magical slumber to come upon 4 HD of creatures. Creatures with the fewest HD are affected first. Among creatures with equal HD, those who are closest to the spell’s point of origin are affected first. HD that are not sufficient to affect a creature are wasted.

Sleeping creatures are helpless. Slapping or wounding awakens an affected creature, but normal noise does not. Awakening a creature is a standard action (an application of the aid another action). Sleep does not target unconscious creatures, constructs, or undead creatures.”

Amie’s Intelligence is a 12, so her Caster Ability Modifier is a +1 and Sleep is a level 1 spell. All together now! 10+ 1 (spell level) + 1 (her intelligence modifier). Therefore Amie’s target, Dana, has to roll above a 12 on her will save to not fall asleep. It’s low, but then again Dana has been drinking all night.

Increasing Your Spell DC

When you choose a caster class, you have stepped into the Magical Arms race. You may be able to cast some high level magic, but if you don’t have a high enough Spell DC, all you will do is annoy your targets instead of making them evaporate in a puff of smoke.

Ability Scores

The first and most common way to do this is to directly increase your Caster Ability Modifier by bumping that ability score.

Every 4 levels you get a +1 to an Ability Score of your choice. As a Caster, it is always more efficient to level your Caster Ability. 

Other methods might come in handy for a direct increase. Wondrous Items like the Headband of Alluring Charisma, Headband of Inspired Wisdom, or Headband of Vast Intelligence. Each one can increase your Ability score ranging from +2 to a whopping +6. 

That would increase poor Amie’s 12 Intelligence to an 18! Making her Caster Ability Modifier a +4 instead of a +1.

The Arithromancy Labs tell me this makes Amie’s Sleep Spell DC 15 rather than a 12.


Pathfinder has options for the discerning character in the form of traits. These are special parts of character creation that make a character different and unique! The DM is the final arbiter of what is available for a player.

The whole list of Traits can be daunting, but we can narrow down the search to a handful of examples. This is not an exhaustive list, but some good examples of what to look for to give your character an extra edge.

Balancer’s Banishing Benefit(s): As long as you remain neutral, whenever you cast a spell that would send an outsider with the chaotic, evil, good, or lawful subtype back to its home plane, the spell’s saving throw DC increases by 1.

DomineeringBenefit(s): Choose one 1st-level enchantment spell you are capable of casting. The DC of that spell increases by 1.

Overwhelming Beauty Benefit(s): The DC of your mind-affecting effects increases by 1 against creatures that have at least one of the same subtypes as you.


There are more than a few races that have traits which can affect the Spell DC directly!

Elves have the alternate trait called Dreamspeaker:
Dreamspeaker: A few elves have the ability to tap into the power of sleep, dreams, and prescient reverie. Elves with this racial trait add +1 to the saving throw DCs of spells of the divination school and sleep effects they cast.

In addition, elves with Charisma scores of 15 or higher may use dream once per day as a spell-like ability (caster level is equal to the elf’s character level). This racial trait replaces elven immunities.

Elves aren’t the only ones though, another good example are Gnomes who have Gnome Magic: Gnomes add +1 to the DC of any saving throws against illusion spells that they cast. Gnomes with Charisma scores of 11 or higher also gain the following spell-like abilities: 1/day—dancing lights, ghost sound, prestidigitation, and speak with animals.

The caster level for these effects is equal to the gnome’s level. The DC for these spells is equal to 10 + the spell’s level + the gnome’s Charisma modifier.

Class Abilities:
Some Classes have their own method of boosting Spell DC believe it or not! Let’s look at the Sorcerer Bloodline ability as an example.

The Fey Bloodline – Whenever you cast a spell of the compulsion subschool, increase the spell’s DC by +2.

The Infernal Bloodline – Whenever you cast a spell of the charm subschool, increase the spell’s DC by +2.


To add to the above, there is the ultimate in character customization: FEATS!

Spell Focus Benefit: Add +1 to the Difficulty Class for all saving throws against spells from the school of magic you select. Special: You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new school of magic.

The Greater version even stacks for a total of +2 for whichever school you pick.

There is also Elemental Focus and its Greater version which add a +1 for a specific energy type, making your fireballs spicier!

Final Analysis

When it comes down to it, Spell DCs are another dimension of making your character effective and also fun to play. The options for increasing Spell DC offer more opportunities for excellent Role Play and more interesting and varied combat.

Enjoy and Good Pathfinding!