A Look into Flanking in D&D 5e

A Look into Flanking in D&D 5e

I grew up playing primarily D&D 3.5e, but I’ve played miniature war games and other types of games all my life. When I found out that flanking is an optional rule in D&D 5e it was fairly surprising.

I have opted to not use it in my games, but after a lot of reading and listening to podcasts like Critical Role, I’ve found that a large number of people use flanking.

Flanking opens up another layer of strategy and more options for martial melee PCs which tend to have few options by default compared to their spellcasting counterparts.

That being said, it’s not for me. I’ll go into the why later on in this post, but before we get there let’s take a look at the flanking mechanics in the Dungeon Master’s Guide (DMG).

What is Flanking

A creature is flanked when two of its enemies are engaged with it on opposite sides. If you can draw a line from one engaged creature to the other they are considered to be flanking.

Any melee PC or creature will benefit from flanking. Ranged creatures and PCs are only going to be concerned with avoiding being flanked by their enemies.

This means that any combat encounter with at least one melee-heavy side is going to be a race to see who can flank the other side. This can make for some very strategic and engaging combat for groups that are big on wargaming.

Flanking is a mechanic that is restricted primarily towards the people who use miniatures and battlemaps. While it can be done in theater of the mind encounters it’s much more difficult to visualize and keep track of.

Mechanics of Flanking

“When a creature and at least one of its allies are adjacent to an enemy and on opposite sides or corners of the enemy’s space, they flank that enemy and each of them has advantage on melee attack rolls against that enemy.”-DMG pg 251

D&D 5e flanking squares
The official D&D 5e flanking diagram for square battlemaps. Art by Wizards of the Coast.

A creature cannot flank if they cannot see their target. They also cannot flank if they are incapacitated. So long as the target can be seen and both creatures are conscious they can flank.

If these conditions are met and your flanking maneuver looks similar to the diagram above you and your ally are flanking your target. If you play with hexagonal battlemaps there’s a diagram for those later in this post or on pg 251 of the DMG.

Remember that flanking only gives advantage on melee attacks. This does not give a ranged character advantage to attack and negate their disadvantage for being in melee range of their target. Crossbow Expert also doesn’t count crossbow attacks in melee range as a melee weapon attack.

My Issues with the 5e Flanking Mechanics

It’s Too Powerful

I’ve written before about how I love the cover rules in D&D 5e because they add another layer of strategy to combat. While flanking also adds more strategy to combat, I feel that being given advantage for something so easy to do in combat is a bit counter-intuitive.

While it does take a minimum of 2 party members’ movement to set up it still grants 2 people a melee attack advantage for the encounter. The creature is forced to use its action to disengage or invoke 2 attacks of opportunity at advantage to break the flank.

The DM must decide if they want the creature to lose a turn or just suck it up and hope for the best.

For classes like rogues and paladins that have heavy burst damage from their Sneak Attack and Divine Smite when they crit easy-to-obtain advantage is a large buff for them.


Advantage in D&D 5e does not stack. You either have advantage or you don’t, full stop. This means that if your monk has successfully stunned a creature, you don’t gain any benefit from flanking the creature with the monk.

It feels underwhelming that you can’t gain some perk for attacking the creature from behind while still having advantage on your attacks.

Flanking can be a huge risk depending on the combat encounter. You may be putting yourself in harm’s way to gain advantage on the attack or give a party member the ability to flank. To have the sorcerer cast Hold Monster after you’ve put yourself in an inopportune position feels lackluster.

Barbarians get the short-end of the stick in my opinion. Flanking can make Reckless Attack feel useless depending on the encounter.

D&D 5e flanking hexes
The official D&D 5e flanking diagram for hex battlemaps. Art by Wizards of the Coast.

The More (Melee) Characters, the Easier it is to Flank

The more people you have stacked on a creature’s hitbox, the more options your party members have to flank a creature. More options mean it’s theoretically easier for the party to obtain advantage in combat.

So long as your party has an even number of melee PCs everyone will be able to flank their target.

For a melee-heavy party flanking is a huge power spike that combat encounters are going to have to be specifically designed around.

This is especially true for melee encounters with a large number of creatures. If a level 5 party is facing off against an ambush of 20 goblins they’re going to have to deal with a lot of flanking.

The Larger the Creature, the Easier it is to Flank

Having a lot of melee party members isn’t the only way to make flanking easier. Using larger creatures also does this. The larger the hitbox the more options the party has to flank.

While being a large creature brings plenty of advantages to the table such as not being able to be grappled.  Giving the party more options to gain advantage is still a significant disadvantage.

For reference, a medium-size creature has 4 different flanking combinations. A large size creature has 6 different combinations. It’s more difficult for a large creature to back up against a wall to prevent the party from flanking them compared to a medium creature.

Large melee-centric creatures without flying or other spells/abilities to prevent the party from flanking them are at a disadvantage.

How I’d Change Flanking

ambush flanking D&D 5e
Ambushes are a great way for enemy creatures to quickly flank the unsuspecting party! Art by Vempirick.

Honestly, I would just bring back the D&D 3.5e/4e rules. If you and a party member are flanking a creature you both will gain +2 to hit on your melee attacks.

The only downside to this line of thought is that it doesn’t “feel” very 5e like. A big draw for D&D 5e is that it’s not bloated with random +X and -Y mechanics that make the game into a huge math problem.

That being said, I’ve already mentioned the cover rules earlier in this post. These also give you a +2 or +5 so this type of mechanic is not unheard of in D&D 5e.

+2 to hit is also a very healthy number for D&D 5e. For example, a +2 longsword is reserved for characters 5th level or higher. You have to take a level in a martial class to gain a +2 to hit with ranged attacks. It’s a big enough number to make a difference in 5e.

A +2 to hit checks off all the boxes for me. There’s a benefit for two party members to flank a creature, and it can still be beneficial when both have advantage on their attacks already.


I like the idea of flanking. It makes sense from a realistic perspective. Hitting an opponent’s blind spot should give you some benefit. It’s also a classic RPG mechanic.

However, the implementation of it in 5e just feels off to me. It’s either too powerful for how easy it is to manage, or it’s redundant. A flat bonus would be better in my opinion.

My optional ruling is for sure going in my list of mechanics I need to test out with my group. I’ll be sure to come back with an update on our findings if we get around to it.

I don’t believe that my group has missed out on anything by not using flanking. Not including it has made advantage in combat feel much more powerful.

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  1. Just a quick reply to tell you that i wholeheartly agree. I don’t use flanking for the same reasons but I am thinking of giving +2 to the attacks.

    1. James Griffith says:

      Thank you! Be sure to tell me how it goes!

  2. Shimon Jayme says:

    I disagree with the first reason you give that the monster will be attacked by 2 attackers with advantage. That depends on the initiative counter. Also disagree that unless you disengage you will incur 2 attacks of opportunity with advantage. The attack of opportunity is caused by leaving the opponents reach. In this case if the monster moves one square down, he is still within reach of both attackers. If he leaves that square, and consequently the reach of the opponents, then he is no longer flanked and the attack of opportunity will not be at advantage. Also he may move around one of the attackers never leaving its reach, and thus incur an attack of opportunity from only one enemy. This is all played with strategy.

    I agree it sucks if you’re playing without minis and a grid, but for those with grids and minis it opens up strategy moves for both sides. A similar attack would be with one weak character who knows he will be missing his attack, to use the “help” action and give his comrade advantage on the attack. And they don’t need to be flanking.

    So I don’t see where it’s overpowered or anything like that. Giving a + 2 on the attack could make it overpowering though. You’re just giving the player extra numbers to hit, making it almost certain he will hit. If the AC to hit is 15, and my advantage rolls are 14 and 13, I miss with the higher number. With a + 2 bonus, if I use the smaller number, 13, that’s a hit. So which one is more overpowered? Flanking to me is just another rule of the game that makes everyone think hard to set up their combatants in the right spots on the battlefield.

    Just my opinion in the flanking rule.

    By the way, fell in love with the blog. I’ll be a regular here. Great job!

    1. James Griffith says:

      Thanks for the comment and I’m glad you’re enjoying the blog!

      Let me address a couple points you’ve made. I don’t believe that advantage in it of itself is overpowered. In fact I really enjoy the mechanic. My issue is that flanking makes it too easy to get this potentially significant bonus.

      Getting advantage from say the Help Action is a o.k. with me. Especially since there’s a significant action economy cost of doing so. Flanking doesn’t have this same cost due to movement being a separate part of a turn in 5e combat.

      Your last point is a bit disengenious. You tailor-made a scenario where advantage was “worse”. Especially considering how advantage can oftentimes be considerably more valuable than a +2 modifier. Check out the math here: http://onlinedungeonmaster.com/2012/05/24/advantage-and-disadvantage-in-dd-next-the-math/

      A flat modifier also has the benefit of not increasing your chances of a nat 20 or reducing your chances of rolling a nat 1. Advantage does. While this is a minor perk, it’s still worth considering with regards to modifier vs. adv/disadv.

      I do agree that flanking as a mechanic opens up a lot of new doors tactics-wise. My issue is that the reward for flanking is, in my opinion, too high for the lack of risk/resources it requires.

      1. Ty Henriksen says:

        Spot on with respect to the initiative counter, but there is still too much advantage with flanking and 2X advantage rolls in many situations.

        Atttacking with advantage gives a player or creature +2.8 1/3, statistically. The +2 gives less but not very much less. Perhaps allowing two flanking players to ‘help’ the other, but doing so not with the help action but by making an attack from the flanking position? If the first player hit , they wouldn’t be able to help the other but if they miss then they can count the miss as help to the next attacker without sacrificing a chance to hit.

        This averages out to something a little better than a random help (from a non flanked position) but at best a +2.8 1/3 to only ONE player in aggregate. You’re now giving 3Xd20 rolls for 2 melee attacks between two creatures attacking from flanks . With a player offering help, they don’t get to roll for a hit so there is still advantage to flanking over helping while not going over the top with how much advantage it offers.

  3. Why you look at flanking only from the players point of view? It really is a two-edged blade, since characters can also be swarmed and flanked by outnumbering enemy )) Makes life somewhat less miserable for creatures like goblins even ))

    1. James Griffith says:

      My issue is with the mechanic itself. Ideally a variant rule like this should add depth and strategy to the game.

      If one side is miserable like you alluded to, that doesn’t feel like it’s adding to the game. In fact, I’d say it’s doing the opposite.

  4. Ty Henriksen says:

    Perhaps another approach gets to where you want to go better.

    Consider two creatures, A and B, flanking an enemy. Here creature A attacks before creature B and both will attack before their enemy . Flanking might be most balanced by allowing creature A to give advantage to creature B merely by making their attack (hit or miss). This is akin to taking the Help action but with the added bonus of getting their own attack. The added benefit comes form being 180 degrees apart. Careful use of the ready action keeps creatures with natural advantage form having their ability diminished and allows creatures to optimize the damage their team does.

    Conisder three scenarios and how many d20s get rolled between them (i.e. the aggregate advantage of a group)

    Scenario 1: Creature A and B coordinate attack without flanking. Creature A takes the Help action to lend advantage to creature B against enemy A.

    Result: 2 x d20s divided between two creatures

    Scenario 2: Creature A and allied creature B flank enemy A. Creature A attacks and by virtue of being in a flanking position lends advantage to creature B.

    Result: 3 x d20s divided between two creatures

    Scenario 3: While in a flanking positions about enemy A, creature A who has no natural advantage on their attack chooses to ready an attack triggered by an ally who already has advantage on their attack (e.g. rogue with sneak attack). Now the naturally advantaged creature attacks first, and by virtue of being in a flanking position, lends advantage to allied creature A whose readied attack gains benefit.

    Result: 4 x d20s divided between two creatures

    With judicious use of the ready action, the best use of the flanking position is always better than merely taking the Help action and the advantage gained from other means need not be diminished. Even if creature A does 2d8 damage and creature B does 1d10, using the ready action can rearrange which order the attacks occur in and lend advantage to the creature most likely to do more damage.