DnD Advantage and Disadvantage Rules

The advantage and disadvantage system is one of the most frequently applied mechanics in Dungeons & Dragons 5th Edition, governing how favorable or unfavorable circumstances translate into modified die rolls. This page covers the precise definition of the mechanic, the procedural steps for applying it, the conditions and situations that commonly trigger it, and the rules for resolving conflicts when both states are present simultaneously. The mechanic appears across attack rolls, saving throws, and ability checks, making it one of the broadest-reaching rules in the system.

Definition and scope

Advantage and disadvantage are binary mechanical states that modify how a d20 is rolled. Under the rules published in the Player's Handbook and reproduced in the D&D Basic Rules (Wizards of the Coast / D&D Beyond), advantage means rolling 2 twenty-sided dice and using the higher result; disadvantage means rolling 2 twenty-sided dice and using the lower result. Neither state produces a numerical bonus or penalty to the roll itself — the modifier applied to the d20 remains unchanged. Only the selection method changes.

The mechanic applies to 3 categories of d20 roll: ability checks, attack rolls, and saving throws. It does not apply to damage rolls, hit dice, or any other non-d20 mechanic. Percentage dice, d6 initiative variants, and other dice types are entirely outside the scope of advantage and disadvantage.

This mechanic integrates with the broader structure of play described in the conceptual overview of how DnD works, where the Dungeon Master interprets fictional circumstances and translates them into mechanical outcomes.

How it works

The procedural sequence for applying advantage or disadvantage is as follows:

  1. Identify the roll type. Confirm that the roll is an ability check, attack roll, or saving throw — the only 3 categories where this mechanic is valid.
  2. Determine the state. The DM or the triggering rule identifies whether the character has advantage, disadvantage, or both.
  3. Roll 2d20. Both dice are physically or digitally rolled at the same time.
  4. Select the applicable die. With advantage, take the higher value. With disadvantage, take the lower value.
  5. Apply modifiers normally. Add the relevant ability modifier, proficiency bonus, or any other applicable bonus to the selected die result, not to both.

The key mechanical distinction from flat bonuses is statistical rather than arithmetic. A +5 bonus to a roll adds exactly 5 to every result. Advantage, by contrast, produces an average effective bonus of approximately +3.3 to +5 depending on the underlying target number — an effect that is larger than +5 when the threshold sits near the middle of the range and smaller when the threshold is very high or very low. This probabilistic relationship is documented extensively in statistical analyses of the 5th Edition rules system.

When rolling with disadvantage and a feature like the Lucky feat allows a third die to be added, the player rolls 3 dice and still takes the lowest, because the disadvantage condition governs the selection rule, not the number of dice.

Common scenarios

The following situations represent the most frequently encountered triggers for advantage and disadvantage in standard play, as documented in the Player's Handbook and the D&D Basic Rules:

Advantage triggers:
- Attacking a prone target from within 5 feet
- Attacking an unseen or hidden target when the attacker can't be seen either (when the attacker is hidden)
- Assisting an ally via the Help action (grants advantage on their next ability check or attack roll)
- Certain class features, such as the Rogue's Sneak Attack prerequisite condition
- Spells and conditions, including Faerie Fire and the Frightened condition in some applications
- Flanking under the optional variant rule

Disadvantage triggers:
- Attacking a prone target from more than 5 feet away
- Making a ranged attack while within 5 feet of a hostile creature (see combat rules)
- Attacking while exhausted at level 3 or higher
- Attacking while restrained, blinded, or poisoned
- Casting a spell requiring a ranged attack roll while in melee range without the Crossbow Expert feat
- Operating in heavily obscured areas or total darkness

Decision boundaries

The most operationally significant rule governing advantage and disadvantage is the cancellation rule: if a character has both advantage and disadvantage on the same roll — regardless of how many sources grant each — the roll is made normally with a single d20. Three sources of advantage and one source of disadvantage still cancel to a straight roll. The number of stacked sources is irrelevant; only the presence or absence of each state matters.

This binary cancellation model contrasts with systems that stack modifiers numerically. In 5th Edition, there is no mechanical benefit to accumulating multiple sources of the same state. Advantage from a spell, a class feature, and a terrain effect simultaneously still produces exactly one roll of 2d20-take-highest.

A related boundary governs interaction with the Elven Accuracy racial feature (found in Xanathar's Guide to Everything). Characters with this feature who have advantage on an attack roll using Dexterity, Intelligence, Wisdom, or Charisma roll 3 dice and take the highest — but only when the advantage has not been canceled by a simultaneous source of disadvantage. The full rules index at dndrules.com covers additional edge cases across class features and optional mechanics.

Dungeon Masters applying difficulty class rules should note that advantage and disadvantage are alternatives to — not stackable with — adjustments to the DC itself. The Dungeon Master's Guide recommends against combining both methods for the same roll, as doing so double-penalizes or double-rewards the same fictional circumstance.

References

Explore This Site

Tools & Calculators Chinese Zodiac Calculator FAQ DnD: Frequently Asked Questions Overview DnD: What It Is and Why It Matters