Saving throws

For a comprehensive summary of the mechanics behind all rolls and modifiers, see Die Rolls.

A Saving Throw, also called a save, is a D20 roll the game makes for a creature to decide whether it can save itself against a special kind of threat, such as a spell, poison, trap, and so on. Each save has a Difficulty Class (DC) which must be reached or exceeded for the save to be successful.

Modifiers

Each Saving Throw is related to a specific Ability Score. (Depending on the ability, the Saving Throw can be referred to as a Strength Save, Dexterity Save, Constitution Save, and so on.) The type of save determines the Modifiers the creature uses. In addition to its Ability Score Modifier, the creature can also add its Proficiency Bonus to the result if it has Proficiency in the corresponding type of Saving Throw. This means the formula is:

Result =  d20 + Ability Score Modifier + (optional) Proficiency Bonus

Ability Score Modifier

Following is the Ability Score Modifier table based on the value of the Ability Score being used for the save:

Ability Score Modifier depending on the value of the Ability Score used

Score	Modifier
1	-5
2-3	-4
4-5	-3
6-7	-2
8-9	-1
10-11	+0
12-13	+1
14-15	+2
16-17	+3
18-19	+4
20-21	+5
22-23	+6
24-25	+7
26-27	+8
28-29	+9
30	+10

Proficiency Bonus

As explained above, a creature needs Proficiency in the corresponding type of Saving Throw for its Proficiency Bonus to apply. Each Class provides a creature Proficiency in two types of Saving Throw:

Saving Throw Proficiencies granted by each Class

Barbarian	Bard	Cleric	Druid	Fighter	Monk
Strength Constitution	Dexterity Charisma	Wisdom Charisma	Intelligence Wisdom	Strength Constitution	Strength Dexterity
Paladin	Ranger	Rogue	Sorcerer	Warlock	Wizard
Wisdom Charisma	Strength Dexterity	Dexterity Intelligence	Constitution Charisma	Wisdom Charisma	Intelligence Wisdom

Following is the table of Proficiency Bonus values, by Level of the creature making the save:

Proficiency Bonus by Level

Level	Proficiency Bonus
1 to 4	+ 2
5 to 8	+ 3
9 to 12	+ 4
13 to 16	+ 5
17 to 20	+ 6

The Difficulty Class of Saving Throws

If a creature casts a spell that forces another to make a save, the DC is determined according to the properties of the spell caster, using the following formula:

Difficulty Class = 8 + Ability Score Modifier + Proficiency Bonus

The Ability Score used to determine the Modifier depends on the class of the caster, and is the same as the one used for the Attack Roll:

Table of classes by which Ability Score they use for spells

Intelligence	Wisdom	Charisma
Wizard Arcane Trickster (Rogue) Eldritch Knight (Fighter)	Cleric Druid Ranger	Bard Paladin Sorcerer Warlock

The Proficiency needed to gain the Proficiency Bonus is spell casting. All creatures capable of casting spells through their Class, Subclass, or Feats, have this proficiency. However, if a creature that can't normally cast spells uses a Scroll or other item to cast one, it will lack the Proficiency Bonus. (TODO: Verify that this is actually implemented in BG3! It's been verified for Attack Rolls, but not the Difficulty Class of Saving Throws imposed on others.)

In case of threats that don't originate from a spell caster, such as a trap that just sprung or a poisonous apple you just ate, the game sets the DC based on how serious the threat is supposed to be. For example, a rather ineffective trap could have a DC of just 5, whereas a very powerful one could have a DC of 15. A slightly spoiled tart could impose a Constitution Save of DC 5, whereas a potent venom from a snake could impose a DC 15 Constitution Save on the hapless victim.

Effects of a successful Saving Throw

Making a successful Saving Throw could mean avoiding negative effects entirely, or it could merely mean reducing the damage taken, usually by half. Depending on the threat, there could also be other rules that determine what happens on a failed or successful save.