Dice rolls
Dice rolls are an important mechanic in Baldur's Gate 3 which determine the outcome of many different situations. For example, determining whether a character will succeed or not at using a particular skill, or if an attack will land and how much damage it will do.
Overview
Whenever a creature attempts something that requires them to roll dice, the game automatically rolls either a single 20-sided die or one or multiple four, six, eight, ten or twelve-sided dice, each die notated with a d followed by the number of sides on that specific die:
d4
d6
d8
d10
d12
d20
The number of dice rolled is notated by with a number placed immediately before the d – when a single twenty sided die (d20) is rolled with no modifiers, it is abbreviated as 1d20, when two six-sided dice (d6) are rolled with a modifier of +2, the roll is abbreviated as 2d6+2.
Any applicable modifiers are then added to the final sum and results of the roll:
- Most rolls have an associated ability, and add a creature's respective ability score modifier to the result of the roll.
- Some rolls allow a creature to add its proficiency bonus to the results of the roll.
- Some equipment, spells, conditions, potions and class features can add a modifier to specific types of rolls.
- Certain environmental effects or circumstances add a modifier to specific types of rolls.
Modifiers may be negative, in which case they may be referred to as penalties.
The range of results is usually given in parentheses. For example, a single dart from a 
spell does 1d4+1 (2-5) Force damage, meaning it rolls 1d4 and adds 1 to the result, giving a possible total of between 2 and 5 points of damage.
d20 rolls
Ability checks, attack rolls and saving throws all require a d20 to be rolled against a target number in order to determine success; attack rolls are rolled against the target's Armour Class (AC), and ability checks and saving throws are rolled against a target Difficulty Class (DC).
If the final result of the roll, after any applicable modifiers are added, is equal to or exceeds the targwt mumber, the attempt was successful.
d20 mechanics
A number of unique mechanics apply to d20 rolls.
Difficulty Class
Difficulty Class (or DC) is a number rolled against when making ability checks on or saving throws. It represents how difficult a task is to accomplish.
The number is determined by the the task attempted, or in the case of saves, the spell, condition or action that has to be overcome.
Danger DC
In scenarios such as traps, the game chooses an appropriate Difficulty Class, depending on how serious the danger is. This includes single-use items such as elemental arrows or throwables.
Spell DC
For the Difficulty class of a spells that can be saved against is determined through the following formula:
Weapon action DC
The Difficulty Class of saves allowed by weapon actions is calculated as follows:
Each weapon action can grant its own inherent bonus DC that isn't listed anywhere, but most frequently it's +2.
Hybrid DC
Certain weapon actions, notably Concussive Smash, instead use allow the acting creatures to either use their spallcaster DC or weapon Action DC with a +2 bonus, whichever is higher.
Natural 1s and 20s
Rolling a 1 or 20 on a d20 roll is referred to as a natural 1 or natural 20. When making an attack roll or ability check, rolling a natural 1 is always an automatic failure, while a natural 20 is always an automatic success, regardless of the the final result after modifiers are applied. Saving throws attempted during dialogue and death saving throws can also roll roll natural 1s and 20s.
Advantage and disadvantage
A creature may have 
advantage or 
disadvantage on a d20 roll. A creature with either advantage or disadvantage rolls twice (depicted in the game as two dice rolled simultaneously) and uses the higher result if they have advantage, or the lower result for disadvantage.
Creatures receive no additional benefit or penalty from having multiple sources of advantage or disadvantage on a dice roll, and still only roll twice. Likesise, creatures that have both advantage and disadvantage on a roll only roll a single die, even if they have multiple sources of either.
Attack rolls
A creature that attacks a target makes an attack roll against the target's AC to determine whether they hit or miss them. If the attack is a hit, it generally deals damage, and the attacker may roll for damage.
Creatures generally make their attacks with their equipped weapon (including unarmed), but some spells – such as a warlock's Eldritch Blast – require the caster to make a spell attacks.
Attack roll modifiers
All attack rolls are made with an associated ability, and creatures add their corresponding ability score modifier to the results of their attack rolls:
- Attacks made with melee weapons, including thrown weapons, generally add the attacking creature's Strength modifier, unless they have the Finesse property, in which case they add either the attacker's Strength or Dexterity modifier, whichever is higher.
- Attacks made with ranged weapons add the creature's Dexterity modifier.
- Spell attacks add the caster's spellcasting ability modifier, generally determined by their class.
Some class features and spells allow a creature to add alternative or additional ability score modifiers to their attack rolls, such as Shillelagh, which allows the caster to add their spellcasting modifier to instead add their attack and damage rolls.
Creatures also add their proficiency bonus to the attack rolls of their spell attacks, as well as to any attack rolls they make with weapons that they are proficient with.
Critical hits
A natural 20 on an attack roll is a critical hit. In addition to being an automatic hit, the creature rolls twice the normal number of dice to determine damage, including additional dice such as those from smites or combat manoeuvres. "Flat" damage bonuses that add a fixed number are not doubled by a critical hit; this includes ability score modifiers, weapon enhancement bonuses and features and abilities like 
.
Some equipment, feats and class features (notably the Champion Fighter's 
) allow a creature to score a critical hit on natural rolls of 19 or 20, or even 18 to 20. The benefits are the same as for a regular critical hit.
Saving throws
Traps, spells, conditions and other sources of harm may allow a creature a chance to avoid or reduce their effect, known as a saving throw or save. This is a d20 roll, with the relevant Ability and Difficulty Class (DC) determined by the source of the effect. If the final result of the roll equals or exceeds the DC, the save is successful.
A creature can be proficient in saving throws on a per-ability basis. Player characters are proficient in two saving throws, based on their class. Proficency adds a creature's proficiency bonus to the saving throw.
Traps, dialogue events and other sources of danger controlled by the game have a DC defined by the game, depending on how serious the danger is. Spells and weapon actions use specific formulas to determine the DC:
- Spell saves have a DC determined by the creature's spellcasting Ability modifier:
- Weapon actions saves have a DC determined by the higher of a creature's Dexterity or Strength, plus an inherent bonus for that specific action:
Unlike attacks, saving throws are not guaranteed to fail or succeed when the d20 result is either a natural 1 or 20 respectively, however when saving throws are used during dialogue they will guarantee failure or success when a 1 or 20 is rolled.
Successful saves
A successful save can mean completely avoiding negative effects, reducing the damage received (usually by half), or both. For example, successfully saving against a spike trap could mean that a creature takes no damage at all, because it successfully evaded the spikes. On the other hand, if it's caught in the area of effect of a 
, then a successful save will merely halve the damage. Saving against 
both halves the damage taken, and prevents a creature from being pushed by the spell.
Some effects don't allow a saving throw, for example the spell 
.
Death saves
When a player character is 
Downed, they make a special Death Saving Throw each turn to determine if they slip closer to death. Death saves are not associated with an Ability Score and so don't add any modifiers or the proficiency bonus. They only benefit from bonuses that apply to all saving throws (such as 
) or specifically to death saves.
Death saves are a success on a result of 10 or higher, and otherwise a failure. A character dies when three failures are accumulated, or becomes Stable (they no longer make death saves) when three successes are accumulated, whichever happens first.
Ability checks
An ability check is an attempt to succeed at a specific task, and is rolled against a Difficulty Class (DC) set by the game for that task. If the final result of the roll equals or exceeds the DC, the attempt is successful.
Ability checks can be triggered by player actions or dialogue choices, or they may be automatic, rolled by the game in the background in response to a trigger in the environment.
Most ability checks have an associated skill. These rolls are often referred to as "skill checks" by the community, although they are not referred to as such in-game. If a creature is proficient with an ability check's associated skill, they may add their proficiency bonus to the results of the roll, in addition to the relevant ability score modifier. Characters with Expertise in a skill add double their proficiency bonus (shown in the interface as separate Proficiency and Expertise bonuses).
Some ability checks are based only on the base Ability Score. A common example is exerting willpower to use the Tadpole's influence on other characters during dialogue. Checks like this have no applicable proficiency, and never add a proficiency bonus.
Other d20 rolls
When a Wild Magic (sorcerer) sorcerer casts a leveled spell, a d20 is rolled to determine if they will trigger a Wild Magic Surge. A surge is triggered only when the outcome is 20. The resulting effect, and Wild Magic Barbarian surge effects for Rage: Wild Magic, are also determined with dice rolls.
Other rolls
Rolls made to determine damage, healing or turn order (initiative) are made with d4, d6, d8, d10 and d12 dice.
Damage rolls
Damage rolls are used in the calculation of damage dealt by weapons, spells and certain special abilities. They use one or more d4s, d6s, d8s, d10s or d12s, adding any relevant modifiers to the result.
Damage rolls always have an associated damage type. For example, a dagger typically deals 1d4
Piercing damage.
Damage rolled after a successful attack with a weapon typically adds the same ability score modifier as the attack roll, but some equipment, spells and class features bypass this.
Damage rolled after a successful attack with a spell generally does not add a modifier, but might depending on the spell, the caster's class, and certain class features. For example, the Warlock's 
invocation allows the warlock to add its Charisma modifier to the damage rolls of the 
cantrip.
Magic items, especially weapons, frequently add bonuses to damage, either as additional dice or flat modifiers. Many class features, feats and other effects can increase damage as well, and some (such as 
) can reduce damage as well.
Healing rolls
Healing restores a target's hit points but otherwise works similarly to damage rolls. Healing rolls may also add modifiers, but there's no general rule for this; any bonuses are determined by the source of the healing. For example, a Potion of Healing restores 2d4+2
hit points. There are many magic items, class features and other effects which also provide bonuses to healing, for example the Life Domain Cleric's 
feature.
Rolling for initiative
When combat starts, all combatants roll for initiative to determine the turn order. This is a d4 roll (a significant departure from the tabletop rules), and adds a creature's Dexterity modifier. Proficiency does not apply, but some items, class features and other special abilities may provide bonuses.
Creatures with the highest rolls act first. Allied player-controlled characters next to each other in the Initiative order effectively act simultaneously; the player can switch between them to coordinate their actions, and the game waits until all such characters have ended their turns to move on to the next non-player creature.
Karmic Dice
When the Karmic Dice option is enabled (it is by default), the game will avoid streaks of very low or very high rolls.
However, Karmic Dice influences all rolls – including those of enemies – and the results always skew toward a positive result for the dice roller. In short, the Karmic Dice setting makes combat encounters quicker and deadlier for both you and your enemies, as attacks are more likely to hit and do higher damage.
Karmic Dice was previously referred to as "Loaded Dice".
