# Can two Large (or larger) creatures flank two Medium creatures who might split attention?

If two Large creatures are on opposite sides of a pair of Medium-sized creatures who are side by side, do the Large creatures gain flanking?

Flanking grants advantage because it's impossible to keep watch of both of them, and defend against it. When two Large creatures are opposite one another, they create two spaces of flanking between them. However, with an ally to engage each, I would think that no flanking advantage would be gained. Whatever benefit you would get from having an opportunity to attack the second target would be negated by having to open yourself up to attack from the other target.

How does this work?
I don't think two creatures can be simultaneously flanked by the same two creatures.

• It would also be worth clarifying which creatures you mean by "those creatures" in your first sentence. Which creatures do you mean in that context; the two large creatures or the two medium creatures who are side by side? Oct 15, 2018 at 23:04
• is this a duplicate of rpg.stackexchange.com/questions/14656/… Oct 15, 2018 at 23:08
• Are the combatants positions like this "O=O" or like this "O--O"? The question makes me think it is about the second case, but would be wrong for me to assume it. Oct 15, 2018 at 23:20
• I added an example image. Is this the scenario you are describing? Oct 16, 2018 at 0:39
• @NautArch those monsters in the picture are large, not gargantuan. For a monster to be gargantuan, it would have to take up a 20x20 space - 4x4 squares, not just four squares total. See roll20.net/compendium/dnd5e/Monsters#content
– Tal
Oct 16, 2018 at 13:38

### Yes, each Medium creature is being flanked by both Large creatures.

According to the flanking rules in the Dungeon Master's Guide (page 251):

A Large or larger creature is flanking as long as at least one square or hex of its space qualifies for flanking.

This means that if a Large creature A occupies a square that would provide flanking with another creature B, then both A and B are flanking.

Flanking on Squares. 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.

In your example, there are two Medium creatures. Both Medium creatures are flanked by squares occupied by the north and south giants. The giants are allies with each other. Therefore, both giants get the advantages of flanking versus the Medium creatures.

• @NautArch facing and flanking are two different optional/variant rules in the DMG. Oct 16, 2018 at 13:24
• @NautArch Ah, yes; I think the picture spells out what the orientation was/is for this problem, though. Oct 16, 2018 at 13:44

# It's not clear; the flanking rules are somewhat self-contradictory.

The optional flanking rule is described on DMG p. 251 (with an image demonstrating it on the previous page):

A creature can’t flank an enemy that it can’t see. A creature also can’t flank while it is incapacitated. A Large or larger creature is flanking as long as at least one square or hex of its space qualifies for flanking.

Flanking on Squares. 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.

When in doubt about whether two creatures flank an enemy on a grid, trace an imaginary line between the centers of the creatures’ spaces. If the line passes through opposite sides or corners of the enemy’s space, the enemy is flanked.

## One interpretation

If you take the "when in doubt" description as the rule, then neither of the Medium creatures are flanked; a line going from the center of each Large creature's space doesn't go through opposite corners/sides of either Medium creature's space. In order for one of the two Medium creatures to be flanked, one of the two Large creatures must move one square north or south (per the image); only one of the two Medium creatures would be flanked at a time.

As such, the situation you describe can never really happen - I don't think the positioning required would allow more than one creature to be flanked by the same pair of enemies.

However, the rest of the description of flanking in those previous 2 paragraphs says that:

A Large or larger creature is flanking as long as at least one square or hex of its space qualifies for flanking.

And the definition of what qualifies for flanking could be taken from the next paragraph:

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

That requirement is certainly met by the parallel quadrants of the Large creatures (e.g. the northeast quadrant of Large creature A and the northwest quadrant of Large creature B). It could reasonably be argued that both Large creatures flank both Medium creatures, because both Large creatures have a square of controlled space that matches a square of the other's controlled space and qualifies for flanking each Medium creature.

If that's the correct/intended interpretation, then there's nothing in the rules that would suggest that the advantage from flanking is canceled out simply because there are multiple flanked enemies.

### Reconciling the two

Ultimately, it's up to DM discretion. The optional flanking rule in 5e is somewhat poorly designed, even setting this contradiction aside (it's trivial to move around an enemy but stay within its reach if you don't provoke opportunity attacks while doing so). If you're the DM, I simply recommend you adjudicate the rule in a way that makes the most sense to you.

• I think the "A Large or larger creature is flanking as long as at least one square or hex of its space qualifies for flanking." bit means that we can use any square they occupy, instead of just THEIR center. Like, to do the math on if we're flanking the human, the left Oni can use the upper-right square, as per the rule, so we take the center of THAT, and we connect it to the right Oni's upper left square. Basically, the rule is written for Medium creatures, and this addon says we should break the Oni into 4 Medium sized pieces, and then if any of those flank, the Oni flanks. Oct 25, 2018 at 13:19