Dice rolls: Difference between revisions

[[File:Deception.png|thumb|A Deception check]]

'''Dice rolls''' are a central game mechanic in ''Baldur's Gate 3''. Dice are rolled to determine the outcome of variety of situations, such as whether or not a character will succeed at using a particular skill, or if an attack will land and how much damage it will do.

Dice are notated with a ''d'' followed by the number of sides on that specific die: {{hlist|

The number of dice rolled is notated by with a number placed immediately before the ''d,'' and any applicable modifiers are given as an addition (if it is a bonus) or subtraction (if is a penalty) after the dice notation. When a single twenty sided die (d20) is rolled with no modifiers, it is notated as {{InfoBlob|1d20}}. When two six-sided dice (d6) are rolled with a modifier of +2, the roll is notated as {{InfoBlob|2d6+2}}.

The range of potential results is usually given in parentheses. For example, a single dart from a {{SAI|Magic Missile|h=20px}} 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.  

A number of modifiers are potentially added to dice rolls. These modifiers can be either bonuses which are {{em|added}} to the result – or penalties, which are subtracted from the results.

Whenever a creature attempts an action that has a chance of failure, they roll a twenty-sided die (d20) against a target number to determine whether the attempt was a success or a failure, and add any applicable modifiers. If the result is equal to or exceeds the target number, the attempt was successful. If the result was lower than the target number, or if the creature rolled a 1, the attempt failed.

; Attack rolls : When a creature attacks a target, they make an attack roll against the target's AC to determine whether the attack is a hit or a miss. If the attack is a hit, it generally deals damage, and the attacker rolls 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 spell attack rolls.

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.

A [[List of sources of advantage|number of situations and conditions]] give creatures advantage or disadvantage on d20 rolls. A creature that makes a roll with advantage rolls two d20 dice separately, and uses the higher of the two results. If they have disadvantage, they choose the lower of the two.

: A contest is a special type of ability check in which two creatures both roll an ability check to oppose each other, and one wins over the other. The creatures don't necessarily roll the same type of check.

:: An example of this is the {{SAI|Shove}} action. The creature attempting the Shove rolls Athletics, and the defending creature rolls either Athletics or Acrobatics (the game chooses the Skill with the highest bonus) to contest the Shove. If the attacker's roll is higher than the defender's, the Shove succeeds; otherwise, it fails.

All classes give save proficiency with two abilities. Though when multiclassing, only the {{em|first}} class taken gives its save proficiencies. An additional save proficiency can be gained by taking the [[Resilient]] feat.

: Certain [[conditions]] and [[List of Equipment that Affect Spell DC|equipment]] worn by the caster can also affect their Spell Save DC.

; Weapon save DC: Most weapons allow proficient users to perform special "weapon actions", which are typically limited to once per short rest (e.g. [[Backbreaker]]). These actions often include the chance to inflict a condition on the target, and these conditions require the target to attempt a Save to avoid them. Each weapon action can grant its own inherent bonus to DC that isn't listed anywhere, but is frequently +2. The Difficulty Class of saves allowed by weapon actions is calculated as follows:  

Death saving throws are a special type of saving throw made by playable characters and companions after they have been {{cond|Downed}}. Death saves are made once per turn while the character remains Downed, and when the character takes damage while Downed. Three successful saves will let a creature stabilize, no longer needing to make death saves to survive, and three failures will lead to the creature becoming {{cond|Dead}}.  

When a creature rolls a natural 20 on an attack roll, the attack is a ''critical hit.'' Critical hits automatically land regardless of the target's AC, and the attacker also rolls twice the normal number of dice to determine damage dealt, including additional dice such as those from smites or combat maneuvers. Modifiers and bonuses – including the creature's relevant ability score modifier and proficiency bonus – are not doubled.

 

Some [[feats]], [[Classes|class features]], and [[items]] [[Critical Hit threshold reduction|reduce]] the critical hit threshold by 1, allowing the creature to land critical hits by rolling either 19 or 20 on attack rolls. Multiple sources of this effect stack, allowing the critical hit threshold to go even lower than 19. See [[list of sources of critical hit threshold reduction]].

Some conditions, such as {{cond|Sleeping}} and {{cond|Paralysed}}, automatically turn all incoming attacks into critical hits.

The AC bonus from Dexterity is typically capped at +2 when wearing [[Armour#Medium armour|medium armour {{note|The [[Medium Armour Master]] feat increases the cap from +2 to +3.}}{{note|A few rare armours have an "Exotic Material" trait that allow the wearer to get the full Dexterity bonus to AC. These include [[Yuan-Ti Scale Mail]], [[Unwanted Masterwork Scalemail]], [[Sharpened Snare Cuirass]], and [[Armour of Agility]].}}]], and is reduced to zero when wearing [[Armour#Heavy armour|heavy armour]].

Other bonuses include things like the [[Fighting style|Defense]] fighting style, which grants +1 AC while wearing armor, and the [[Cloak of Protection]].

: {{InfoBlob|10 + Constitution modifier† + Dexterity modifier + shield bonus + other bonuses and penalties}}

: {{InfoBlob|10 + Wisdom modifier† + Dexterity modifier + other bonuses and penalties}}

* When making weapon attacks, the attacking creature usually adds the ability score modifier that they added to the attack roll.

Proficiency bonuses are {{em|not}} added to damage rolls unless the attack being used (e.g. [[Shadowsoaked Blow]]) says so.

; Healing : [[Healing]] restores a target's [[hit points]] in a similar manner 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 {{DamageText|2d4+2|Healing}}. There are many magic items, class features, and other effects which also provide bonuses to healing, for example the {{Class|Life Domain}}'s {{SAI|Disciple of Life}} feature.

When the Karmic Dice option is enabled (it is by default), the game will avoid streaks of very low or very high rolls.

Notice how often the 5 appears in the possibilities for the '''total value''' (4 out of 16 possibilities) vs. how often the 8 appears (1 out of 16).  This means a 2d4 roll has a 25% chance of resulting in 5 points of damage, but only a 6.125% chance of resulting in 8 points of damage.  Meanwhile, the 1d8 roll actually has a higher chance of resulting in the maximum damage value of 8, since 1 out of 8 possibilities (12.5%) result in an 8. However, the average roll of 2d4 is 5 damage, while the average roll of 1d8 is only 4.5. Therefore, 2d4 is generally more consistent in damage output and will result in higher rolls in the long run.  

|9||60% ||84%|| 42.25%

==== Effects of advantange on the average of dice rolls ====

When we apply this expression to a d20, the results is that having advantage is equivalent to an average bonus of +3.325.

Because of symmetry, having disadvantage instead of advantage means we can simply make the permutation of {{math|\{1, \dots, n\} \to \{n, \dots, 1\} }} for the values of dice rolls and all the calculations will remain the same. Therefore the size of the bonus of advantage is equal to the size of the penalty of disadvantage.

==== Effects of advantage on criticals ====

Having advantage or disadvantage can drastically increase or reduce the chance of critical successes and Failures. For example, when rolling with advantage, the only way to get a Critical Failure is to roll {{em|two}} 1s at the same time. The odds of this result is {{math|1=1/20 \cdot 1/20 = 1/400}} (or 0.25%). Conversely, rolling a Critical Success is far more likely - out of the 400 possible dice roll outcomes,  39 will result in a 20 (rolling 20 on the first die and 1, 2, 3, ... 20 on the second die, plus rolling 20 on the second die and 1, 2, 3, ... 20 on the first die, minus one so that the result of two 20s is not doubly-counted). The odds of this result is {{math|39/400}} (or 9.75%). The opposite is true for rolling with Disadvantage: a Critical Success has a 0.25% chance and a Critical Failure has a 9.75% chance.