Advantage and Disadvantage in 5e: How It Changes Your Odds

How does advantage work in 5e?

When you have advantage on a d20 roll, you roll two d20s and use the higher number. When you have disadvantage, you roll two d20s and use the lower. You then add your modifiers to that one die as usual. You can try it on the d20 roller by rolling two dice at once.

Advantage and disadvantage apply to d20 rolls: attack rolls, ability checks and saving throws. The 2024 rules group these three together under the name "D20 Tests", but the mechanic is the same as in 2014. They never apply to damage rolls.

In dice notation, advantage is 2d20kh1 (keep highest) and disadvantage is 2d20kl1 (keep lowest). The dice notation guide explains those codes.

Does advantage stack in 5e?

No. These rules are the same in the 2014 and 2024 Player's Handbooks:

• No stacking: three sources of advantage still mean rolling just two d20s.
• They cancel: if you have at least one source of advantage and at least one of disadvantage, you have neither and roll one d20.
• Count doesn't matter: four reasons for advantage and one for disadvantage still cancel completely.

This makes advantage simple to track, but it also means a single bad circumstance can wipe out every benefit you lined up. It's worth checking for disadvantage before you spend resources to get advantage.

What gives you advantage?

• Unseen attacker: attacking a creature that can't see you.
• Prone target: melee attacks against a prone creature within 5 feet (ranged attacks against it have disadvantage instead).
• Help: an ally takes the Help action to assist your check or attack.
• Class features and spells: for example the Barbarian's Reckless Attack, or the light from Guiding Bolt on the next attack against its target.

What gives you disadvantage?

• Unseen target: attacking a creature you can't see.
• Ranged attack up close: making a ranged attack while an enemy is within 5 feet of you.
• Conditions: being poisoned, frightened (while the source is in sight), restrained or prone (on your own attacks) all impose disadvantage on certain rolls.

Did Inspiration change in 2024?

Yes. In the 2014 rules, spending Inspiration gives you advantage on one roll. In the 2024 rules it became Heroic Inspiration, which lets you reroll one die instead of granting advantage.

How much does advantage change your odds?

The chance of failing with advantage is the chance that both dice fail, so it is the normal failure chance squared. With disadvantage you need both dice to succeed, so it is the normal success chance squared.

For example, if you need an 11 or higher, a normal roll succeeds 50% of the time. With advantage you fail only if both dice miss: 0.5 × 0.5 = 25%, so you succeed 75% of the time. With disadvantage you need both to hit: 25%.

The table shows the d20 number you need (after subtracting your modifier) and the exact chance to succeed. Each +1 bonus on a d20 is worth 5%, so the last column converts the change into an equivalent flat bonus.

These numbers ignore the automatic hit on a natural 20 and automatic miss on a natural 1 for attacks. That rule only matters when you need a 21 or more, or a 1 or less, after modifiers.

Is advantage worth +5?

Only near the middle. The common rule of thumb says advantage is worth about +5 and disadvantage about −5, and the table shows that's right when you need roughly 9 to 13. The further the target is from the middle, the less it helps:

• Need 11: 50% becomes 75%, the full +5.
• Need 6 or 16: a 18.75 point swing, worth about +3.75.
• Need 4 or 18: worth about +2.55.
• Need 2 or 20: worth under +1.

Averaged over every possible target, the gain is 16.63 percentage points, which equals about +3.3. You can see the same figure another way: the average result on a single d20 is 10.5, the average of the higher of two d20s is 13.83, and the average of the lower is 7.18. That is a shift of about 3.3 in either direction. So "about +3 overall, up to +5 near the middle" is the most accurate summary.

Why does advantage help less at the extremes?

If you need a 2, you already succeed 95% of the time, so there is little room to improve. If you need a 20, both dice have only a 5% chance each, so even two tries rarely get there. Advantage does the most when your odds are close to a coin flip.

How does advantage affect critical hits and natural 1s?

Advantage nearly doubles your chance of a critical hit, from 1 in 20 to almost 1 in 10, and makes a natural 1 a 1 in 400 event. That's why features that grant advantage pair so well with extra crit damage, such as a Rogue's Sneak Attack dice or a Paladin's smite. See natural 20 odds and critical hits in 5e for more.

Is disadvantage as bad as advantage is good?

Yes, exactly. For any target, the success chance gained by advantage equals the success chance lost by disadvantage. If you need an 8, advantage adds 22.75 points (65% to 87.75%) and disadvantage removes 22.75 points (65% to 42.25%). The two are mirror images, which is also why one of each cancels out so neatly.

FAQ

Does advantage stack in 5e?

No. No matter how many things give you advantage, you roll only two d20s and keep the higher. The same is true of disadvantage.

What happens if you have advantage and disadvantage at the same time?

They cancel out and you roll a single d20, even if you have several sources of one and only one source of the other.

How much is advantage worth in 5e?

It depends on the number you need. It is worth about +5 when you need an 11, close to +3.3 averaged across all targets, and only about +1 when you need a 2 or a 20.

What are the odds of a critical hit with advantage?

9.75%, nearly double the normal 5%. With disadvantage the chance of a natural 20 drops to 0.25%, or 1 in 400.

Is advantage the same as rolling 2d20 and adding them?

No. You roll two d20s but keep only the higher one. In dice notation that is 2d20kh1, while disadvantage is 2d20kl1.

Related

• Roll a d20
• Odds of Rolling a Natural 20 (and with Advantage)
• Critical Hits in 5e: How Crit Damage Works
• Dice Notation Guide: What 2d6+3 Means and How to Read Any Roll