Can a Beholder face its Antimagic Cone behind itself?

Question

The text for a Beholder's Antimagic Cone ability reads as follows (MM, pg. 28):

The beholder's central eye creates an area of antimagic, as in the antimagic field spell, in a 150-foot cone. At the start of each of its turns, the beholder decides which way the cone faces and whether the cone is active. The area works against the beholder's own eye rays.

The ability states the beholder decides which way the cone faces, and provides no limitations, so would the Beholder be able to face the cone directly behind itself?

Answer 1

A Beholder has no 'behind itself'.

The Beholder creates the anti-magic field with its central eye, so if you consider the location of the central eye 'front' and the other side 'back', then no, it can only ever project its anti-magic field to its front side.

But for all purposes, a Beholder doesn't really have a front or a back, because it's not limited to only being able to see in one direction. You and I have (presumably) two eyes, set in the front of our head, which creates a vulnerable back side, which is where our conception of a 'in front' and 'behind' comes from.

A Beholder on the other hand has lots of eyes that can all move independently of one-another. It has 360 vision and is not limited to a front or a back, it can see and disintegrate you even if you're below, above or 'behind' him.

In fact, this has to be how Beholders operate, because its own anti-magic cone will also cancel its own eyerays, so a Beholder can't even keep its intended ray-targets in its 'front'.

It has a side where food goes in and a lot of sides where deadly rays come out.

Answer 2

It depends on what you mean by "behind itself."

From a narrative standpoint, the cone is emitted from the Beholder's central eye. So it extends forwards from the front of the creature. If the DM has described that the Beholder is facing north, and you are to the south of it, you should be out of the cone (unless the Beholder physically turns around).

The text comes from a tactical standpoint. If the Beholder has previously had the cone facing north, they can redirect it to the south ("behind them") at the start of their turn. They aren't restricted or bound by their previous facing.

It's basically just a cheap way of dealing with a creature whose facing is very important in a game that otherwise ignores facing in combat.

Answer 3

By default there is no facing in 5e

The standard rules do not use the concept of facing. All combatants are supposed to see in all directions, as they are moving in their space to respond to threats. It is not defined in which direction the front or back of a combatant is facing.

This can be seen as the DMG on p.252 offers:

OPTIONAL RULE: FACING If you want the precision of knowing which way a creature is facing, consider using this optional rule.

So, while the beholder has a front side (from which the anti-magic cone issues) and a back side, in combat by default it is not defined which way the front side faces. That is the reason why the monster's description instructs you to decide, each round which way the cone (and with it the eye) faces. Without general facing rules, you need to add on some kind of facing mechanism, otherwise, it would cover a 360 degree circle instead of a cone.

There still is no mechanical advantage for attacking the beholder from "behind", i.e. the side in which he is not facing with his main eye that round. You can justify that due to the other 10 eyes the beholder has, which allow him to look in all directions.