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
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.
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
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.