D&D 5e Advantage & Disadvantage Roller

Roll two d20s, keep the higher (advantage) or lower (disadvantage), add a modifier. Crits and fumbles are flagged on the kept die.

Advantage Disadvantage

Roll

Modifier

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click Roll

How does advantage work?

When you have advantage on a d20 roll, you roll 2d20 and use the higher result. With disadvantage, you use the lower. Add your modifier to the chosen die — that's your final result. In dice notation: 2d20kh1 (advantage) or 2d20kl1 (disadvantage).

When do you have advantage?

• Help action. An ally uses their action to assist your next ability check or attack within 1 round.
• Hidden / unseen attacker. Attacking a target that can't see you grants advantage on the attack roll.
• Prone target (melee). Melee attacks against a prone creature have advantage; ranged attacks against a prone target have disadvantage.
• Restrained target. Attack rolls against a restrained creature have advantage.
• Class & race features. Lucky halfling, Reckless Attack barbarian, Pack Tactics, etc.
• Spells. Faerie Fire, Bless's bigger sibling Bane (gives disadvantage to the target), Foresight, etc.

Do advantage and disadvantage stack?

No. RAW (Player's Handbook p. 173): "If circumstances cause a roll to have both advantage and disadvantage, you are considered to have neither of them, and you roll one d20." It doesn't matter how many sources of each you have — even three advantages and one disadvantage cancel out to a flat roll.

Math: how much does advantage actually help?

Roll-with-advantage doesn't just shift the average — it changes the shape of the distribution. The average d20 roll is 10.5; with advantage it rises to about 13.825, and with disadvantage falls to about 7.175. Advantage is roughly equivalent to a +5 bonus when you need to roll a 10–11, but its value drops at the extremes (it's worth less than +5 against very easy or very hard DCs).

Want a full dice roller?

The main app handles arbitrary formulas — attack + damage in one chain, save-or-suck spells, sneak attack, fireball — with history, saved formulas, and the same crit/fumble highlights you see here.

Open the full dice roller →