Dice Rolls
D20 Tests
When the outcome of an action is uncertain, the game uses a d20 roll to determine success or failure. These rolls are called D20 tests, and they come in three kinds: ability checks, saving throws, and attack rolls.
- Roll 1d20. You always want to roll high. If the roll has Advantage or Disadvantage, you roll two d20s, but you use the number from only one of them – the higher one if you have Advantage or the lower one if you have Disadvantage.
- Add Modifiers. Add these modifiers to the number rolled on the d20.
- The Relevant Ability Modifier.
- Your Proficiency Bonus if Relevant. Each creature has a proficiency Bonus, a number added when making a D20 Test that uses something such as a skill, in which the creature has proficiency.
- Circumstantial Bonuses and Penalties. A class feature, a spell, or another rule might give you a bonus or penalty to the die roll.
- Compare the Total to a Target Number. If the total of the d20 and its modifiers equals or exceeds the target number, the D20 and its modifiers equals or exceeds the target number, the D20 Test succeeds. Otherwise, it fails. The Dungeon Master determines target numbers and tells players whether their rolls are successful. The target number for an ability check or a saving throw is called a Difficulty Class (DC). The target number for an attack roll is called an Armor Class (AC), which appears on a character sheet or in a stat block.
Ability Checks
An ability check represents a creature using talent and training to try to overcome a challenge, such as forcing open a stuck door, picking a lock, entertaining a crowd, or deciphering a cipher. the DM and the rules often call for an ability check when a creature attempts something other than an attack that has a chance of meaningful failure. When the outcome is uncertain and narratively interesting, the dice determine the result.
Ability Modifier
An ability check is named for the ability modifier it uses: a strength check, and intelligence check, and so on. Different ability checks are called for in different situations, depending on which ability is most relevant.
Strength – lift, push, pull, or break something
Dexterity – move nimbly, quickly, or quietly
Constitution – push your body beyond normal limits.
Intelligence – Reason or remember
Wisdom – notice things in the environment or in creatures behavior
Charisma – Influence, entertain, or deceive
Proficiency Bonus
Add your Proficiency Bonus to an ability check when the DM determines that a skill or tool proficiency is relevant to the check and you have that proficiency. For example, if a rule refers to a Strength (Acrobatics or Athletics) check, you can add your Proficiency Bonus to the ehck if you have proficiency in the Acrobatics or Athletics skill.
Difficulty Class
The Difficulty Class of an ability check represents the task’s difficulty. The more difficult the task, the higher its DC. The rules provide DCs for certain checks, but the DM ultimately sets them. The typical Difficulty Classes table presents a range of possible DCs for ability checks.
DC 5 = Very Easy
DC 10 = Easy
DC 15 = Medium
DC 20 = Hard
DC 25 = Very Hard
DC 30 = Nearly Impossible
Saving Throws
A saving throw – also called a save – represents an attempt to evade or resist a threat, such as a fiery explosion, a blast of poisonous gas, or a spell trying to invade your mind. You don’t normally choose to make a save; you must make one because your character or monster (if you’re the DM) is at risk. A save’s result is detailed in the effect that caused it. If you don’t want to resist the effect, you can choose to fail the save without rolling.
Saving Throw Examples
Strength – physically resist direct force
Dexterity – Dodge out of harm’s way
Constitution – Endure a toxic hazard
Intelligence – recognize an illusion as fake
Wisdom – resist a mental assault
Charisma – Assert your identity
Ability Modifier: Saving throws are named for the ability modifiers they use: a constitution saving throw, a wisdom saving throw, and so on. Different saving throws are used to resist different kinds of effects.
Proficiency Bonus: You add your proficiency bonus to your saving throw if you have a proficiency in that kind of save
Difficulty Class: The Difficulty Class for a saving throw is determined by the effect that causes it or by the DM. For example, if a spell forces you to make a save, the DC is determined by the caster’s spellcasting ability and Proficiency bonus. Monster abilities that call for saves specify the DC.
Attack Rolls
An attack roll determines whether an attack hits a target. An attack roll hits if the roll equals or exceeds the target’s armor class. Attack rolls usually occur in battle, but a DM could choose for them to occur in other situations, such as an archery competition.
Ability Modifier
Strength: Melee attack with a weapon or an unarmed strike
Dexterity: Ranged attack with a weapon
Varies: Spell attack (the ability used is determined by the spellcaster’s spellcasting feature.
Some features let you use different ability modifiers from those listed. For example, the Finesse property lets you use Strength or Dexterity with a weapon that has that property.
Proficiency Bonus: You add your proficiency bonus to your attack roll when you attack using a weapon you have proficiency with, as well as when you attack with a spell.
Armor Class: A creature’s armor class represents how well the creature avoids being wounded in combat. The AC of a character is determined at character creation, whereas the AC of a monster appears in its stat block.
AC is calculated at a base of 10+ dexterity modifier + armor (can be modified with magic items, spells, and more).
Rolling 20 or 1: If you roll a 20 on the d20 (called a natural 20) for an attack roll, the attack hits regardless of any modifiers or the target’s AC. This is called a critical hit. If you roll a 1 on the d20 (natural 1) for an attack roll, the attack misses regardless of any modifiers or the target’s ac.
Advantage/Disadvantage
Sometimes a d20 test is modified by Advantage or Disadvantage. Advantage reflects the positive circumstances surrounding a d20 roll, while disadvantage reflects negative circumstances. You usually acquire Advantage or Disadvantage through the use of special abilities and actions. The DM can also decide that circumstances grant Advantage or impose Disadvantage.
Roll Two D20’s: When a roll has either Advantage or Disadvantage, roll a second d20 when you make the roll. Use the higher of the two rolls if you have Advantage, and use the lower roll if you have disadvantage. For example, if you have Disadvantage and roll an 18 and a 3, use the 3. If you instead have Advantage and roll those numbers, use the 18.
They Don’t Stack: If multiple situations affect a roll and they all grant Advantage on it, you still roll only two d20s. Similarly, if multiple situations impose Disadvantage on a roll, you roll only two d20. If circumstances cause a roll to have both Advantage and Disadvantage, the roll has neither of them and you roll one d20. This is true even if multiple circumstances impose Disadvantage and only one grants Advantage or vice versa. In such a situation, you have neither Advantage nor Disadvantage.
Interactions with Rerolls: When you have Advantage or Disadvantage and something in the game lets you reroll or replace the d20, you can reroll or replace only one die, not both. You chose which one. For example, if you have Heroic Inspiration and roll a 3 and an 18 on an ability check that has Advantage or Disadvantage, you could expend your heroic inspiration to reroll one of those dice, not both of them.
Heroic Inspiration: Sometimes the DM or a rule gives you Heroic Inspiration. If you have Heroic Inspiration, you can expend it to reroll any die immediately after rolling it, and you must use the new roll. You can never have more than one instance of Heroic Inspiration. If you already have Heroic Inspiration and receive another one, you can give that to another player in your group who lacks it. Heroic Inspiration can be granted by the DM if you do something particularly heroic, in character, or entertaining. It is a reward for making the game fun for everyone playing. Human characters start the day each day with a heroic inspiration.
Proficiency
Characters and monsters are good at various things. Some are skilled with many weapons, while others can use only a few. Some are better at understanding people’s motives, and others are better at unlocking the secrets of the multiverse. All creatures have a Proficiency Bonus, which refelcts the impact that training has on the creature’s capabilities. A characters’s Proficiency Bonus increases as the character gains levels. A monster’s proficiency bonus is based on its challenge rating. The Proficiency Bonus table shows how hte bonus is determined.
The bonus is applied to a D20 test when the creature has proficiency in a skill, in a saving throw, or with an item that the creature uses to make the d20 test. The bonus is also used for spell attacks and for calculating the DC of saving throws for spells.
Bonus:
Level up to 4 = +2
5-8 = +3
9-12 = +4
13-16 = +5
17-20 = +6
21-24 = +7
25-28 = +8
29-30 = +9
Your proficiency Bonus can’t be added to a die roll or another number more than once. For example, if a rule allows you to make a Charisma (Deception or Persuasion) check, you add your Proficiency Bonus if you’re proficient in either skill, but you don’t add it twice if you’re proficient in both skills.
Occasionally, A Proficiency Bonus might be multiplied or divided (doubled or halved) before being added. Fore example, the Expertise feature doubles the Proficiency Bonus for certain ability checks. Whenever the bonus is used, it can be multiplied only once and divided only once.
Saving Throw Proficiencies
Proficiency in a saving throw lets a character add their Proficiency Bonus to saves that use a particular ability. Some monsters also have a saving throw proficiencies , as noted in their stat blocks. Each class gives proficiency in at least two saving throews, represeting that class’s training in evading or resisting certain threats.
Equipment Proficiencies
A character gains proficiency with various weaons and tools from their class and background. There are two categories of equipment proficiency.
Weapons: Any can wield a weapon, but proficiency makes you better at weilding it. If you have proficiency with a weapon, you add your Proficiency Bonus to attack rolls you make with it.
Tools: If you have proficiency with a tool, you cna add your Proficiency Bonus to any ability check you make that uses the tool. If you have Proficiency in the skill that’s also used with that check, you have Advantage on the check too. This means you can benefit from both skill and proficiency and tool proficiency on the same ability check.