If you’re relatively new to Dungeons & Dragon Fifth Edition, you may have heard the terms "advantage" and "disadvantage" thrown around.
They’re fairly easy concepts on their own. But, as with a lot of aspects of any roleplaying game, they come with their own set of complications and uses.
So, I’m going to go over what 5e’s advantage system is, a few examples of how and when you’d get it, and some of the math behind why you want it.
To start, let’s go over what advantage in 5e is.What is Advantage and Disadvantage in DnD 5e?
Advantage is a mechanic in 5e that let’s you roll 2 20-sided die and use the higher of the two.
Page 173 of the Player’s Handbook, or the Using Ability Scores page on DnD Beyond, explains advantage and disadvantage as follows:
"Sometimes a special ability or spell tells you that you have advantage or disadvantage on an ability check, a saving throw, or an attack roll. When that happens, you 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."
Basically, 5e’s advantage and disadvantage rules either help you make or fail a roll. And, if you want to get spicy with it, having advantage helps significantly when you’re trying to roll for critical hits in 5e. We’ll get to the math later on.
Whether that roll happens out while you’re adventuring or you’re attempting one of the many actions in DnD’s combat, as long as you’re rolling a d20, you might be able to make your roll with advantage (or disadvantage).
What if a Creature Has Advantage & Disadvantage?
This often happens over the course of a 5e game.
Something happens and your character gains both advantage and disadvantage. This can happen because of DnD 5e’s heavily obscured rules, because everyone’s fighting with the blinded condition, or any of a myriad of niche situations unique to your game.
The important thing to remember is if you have both advantage and disadvantage on any roll, you roll as if you had neither. Or, often called a "straight roll."
But, what if you have multiple instances of advantage and only one instance of disadvantage?
Doesn’t matter.
Again, page 173 of the PHB explicitly states this.
"If circumstances cause a roll to have both advantage and disadvantage, you are considered to have 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."
Jeremy Crawford, Lead Rules Designer at Wizards of the Coast, also confirmed this on Twitter stating:
"Advantage and disadvantage cancel each other regardless of the number of things that give either of them to you. Either you have advantage/disadvantage or you don’t. Instances of them don’t stack up."
So, no amount of sources granting you advantage can cancel out one instance of disadvantage.
How to Get Advantage in 5e
Now, the question on everyone’s mind is how do I get advantage? Because why wouldn’t you want to make a roll with advantage at any opportunity possible?
Well, here’s the thing; getting advantage can be a little fuzzy.
Sure, there are mechanical ways to get advantage in 5e (like the optional flanking rule or attack a creature with the blinded condition). But, there are also a myriad of ways that result from good roleplay or just because your DM likes the way you think.
Here’s a list of some of the most common ways to gain advantage and impose disadvantage in DnD:
- Using the Help action grants advantage to another creature for their next ability check
- The Help action can also give advantage on an attack roll to another creature within 5 ft. of you
- Taking the Dodge action imposes disadvantage on all attacks against you until the start of your next turn
- The Dodge action also gives you advantage on all Dexterity saving throws until the start of your next turn
- Attacking a creature that hasn’t seen you yet gives you advantage on the attack
- You have disadvantage on attacks against targets you can’t see
- The various conditions grant or impose advantage and disadvantage (such as prone granting advantage on attacks against you for creatures within 5 ft. of you)
- The optional Flanking rule in the Dungeon Master’s Guide gives you advantage on attack rolls if a friendly, non-incapacitated creature is on the opposite side of an enemy you’re targeting
- Level 1 Exhaustion imposes disadvantage on all ability checks and Level 3 Exhaustion does the same on all attack and saving throw rolls
And honestly, the list goes on. Interestingly, the Lucky feat doesn’t grant advantage, it just lets you roll 2d20 and you pick which one you want.
Remember; this isn’t an exhaustive list. Nor can an exhaustive list every truly be made. Because, yes, there are a finite number of mechanical ways to get advantage or disadvantage in DnD 5e. But, if you do something cool or downright stupid, your DM might give you advantage or disadvantage based on the situation.
But, if you’re looking for a fairly decent list of ways to get advantage, this Reddit post has a pretty robust number of ways.
DnD 5e Advantage Probability
Alright. Here’s the section for the stats nerds.
Probability has never been my strongest field. So, I’m gonna simplify things as much as possible because that’s the only way I understand it.
First off, let’s look at a d20.
With 20 different options, the chance of rolling any one of those numbers is 5%. So, all things being equal, you have a 50% chance of rolling 1-10 or 11-20. Easy enough, right?
Well, the simple act of adding another d20 with advantage skews the whole thing upward.
According to this post on Probabilities for Advantage and Disadvantage the chances of you rolling an 11 or higher (base 50%) increases to 75%. Now, that number skews larger or smaller depending on which direction you go (for example, the odds of rolling higher than a 16 with advantage is a difference of 18.7%). But, you can see how having advantage is…well, a huge advantage.
On the flip side, disadvantage is equally great. And, when I say "great", I mean horrible.
To the same degree that advantage gives you a 25% increase to rolling an 11 or higher, disadvantage decreases the chance by an equal measure. That’s right, you have a roughly 25% chance of rolling an 11 or higher with disadvantage.
Now, that all bars any bonuses from your ability scores and/or various proficiencies. These numbers come from a flat, boring, unmodified d20 roll.
There’s some advice I’ve seen on various posts around the community stating that advantage and disadvantage are equivalent to a +/-5 to any roll. This is because if each number on a d20 equals 5% and rolling an 11 with advantage should happen about 75% of the time (instead of the base 50%), the easy math is there.
5% = 1 number on a d20. So, 25% (the increase in probability) = 5 numbers. Which means you’re basically increasing your roll by 5, right?
Ehhhhhhhh, kinda. It…doesn’t quite work that way.
The Columbia post above illustrates 5e’s advantage and disadvantage curves. Too far in either direction (lower numbers vs higher) shrinks the benefit or detriment granted. For example, rolling a 17 or higher on a flat die roll has a 20% chance of success. But, with advantage, that increases to roughly 36%…which is about the equivalent of a +3 (36 – 20 = 16, 16 / 5 = ~3).
Am I saying you shouldn’t use the +/-5 and meticulously assign modifiers based on the advantage/disadvantage curve?
Absolutely not. The flat modifier works for how its intended. Now, I don’t advocate using it over the advantage/disadvantage system. I’d recommend sticking with the system as is. But, for passive skills (usually passive Perception), its works fine.
That about covers advantage in DnD 5e.
It boils down to you get to roll 2 d20 for an ability check, attack, or saving throw and either choosing the better or worse between them. There’re loads of ways to get advantage in 5e. And, the math behind the system shows exactly how much advantage helps and disadvantage hurts your chances of succeeding any given roll.
One final tip for Dungeon Masters; don’t skimp on either of them.
If a player wants to do something thematic and cool, give them advantage on their roll. Or, if you want to demonstrate the difficulty of a situation (a wide chasm to jump or a disagreeable noble to persuade), have them roll with disadvantage. It’s a tool that helps demonstrate the likelihood of success. So, use it.
Calculating your positive outcome is difficult, but calculating a negative outcome is easy. 5% flat only applies on the outer cases, your middle case, (50% hit chance) has an increase of 25%, your upper and lower quarter case (75% hit and 25% chance) has an increase of 18.75%.
The average increase is in fact 16.6625%, so whoever is saying 5% flat is clueless.
Note that bless averages to 12.5% so advantage is actually better (and advantage increases crit and decreases critical fail, which bless does not affect), though getting advantage should normally not be guaranteed whereas bless is.
Additionally, note that Advantage stacks with bless
Scorching ray, which most people would consider pretty bad because of the hit chance, can actually be a strong spell when cast with advantage. The hit chance is often somewhere between 40% and 60% so your hit would increase 24% at least which proportionally to the original hit chance, is an insane increase.
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As for calculating the chances, here’s an example on how to do it:
Chance to make a crit = 0.05, so the chance to NOT make a crit is 0.95 (the negative outcome)
Chance to miss two crits = 0.95 * 0.95 = 0.9025
Chance to hit a crit with advantage then is = 1 – 0.9025 = 0.0975 (or in other words your chance of landing a crit nearly doubled)
To validate if you did it right, with advantage you know your chances IMPROVE, so the chance should be higher than the single roll.
When looking at a critical fail, the positive result is rolling a 2 to a 20, the negative is rolling a 1. So my negative result chance is 0.05
Chance of doing that twice = 0.05 * 0.05 = 0.0025
My chance to hit is 1-0.0025 = 0.9975 (or in other words, it becomes REALLY hard to make a critical fail)
Again, the math should be to my “advantage” so I know the number should reduce, so I know this is correct.
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I’ve made a simulation with 50000 rolls and the results are:
Advantage % increase: 16.79% (equal to a bit more than +3 dice roll)
Disadvantage % decrease: 16.69% (equal to a bit more than -3 dice roll)
(I’d say that’s close enough to our theoretical 16.6625%)
Bless increase % on average roll: 12.59% (equal to a +2.5 dice roll)
Advantage increase % with bless included: 29.38% (equal to a bit less than +6 dice roll)
disadvantage decrease % with bless included: 4.33% (equal to a bit less than -1 dice roll)
Your link to the Reddit post is severely outdated. There are several other ways of granting advantage that are not listed there.
It is, but it does include a good number of ways of gaining advantage still. I’m working on a comprehensive list of ways to gain advantage and impose or suffer disadvantage. It’s…a lengthy list, so it’s gonna take me a bit to finish.