We're running the Dragon Heist campaign and the party is facing Xanathar.
The bard came up with an idea to distract the Beholder with the Major Image spell.
The description of the Major Image spell says:
Physical interaction with the image reveals it to be an illusion, because things can pass through it.
But what about a magical interaction from a Beholder's ray?
- Beholder's rays are definitely not a "physical interaction", but should the Beholder notice that his rays are just going "through" the target, not affecting it at all?
- Or he shouldn't be able to see that the ray went through the target because he can't see what's behind the target?
- Or the Beholder should notice the strange fact that the target hasn't even flinched when it was attacked by a super deadly and scary ray?
- Or maybe the "experienced" Beholder would know, that sometimes such stuff happens when his enemies "succeed with the saving throw" 😁 or when the enemies are somehow immune to some of his rays?
- So if the Beholder is targeting a well-known seasoned warrior, it should not surprise him that his rays are not affecting the character, like, at all?
- So the Beholder should continue to waste his rays on the illusion indefinitely? Or when should it stop?
- Or maybe it IS actually a viable tactic to indefinitely fool the Beholder with the Major Image illusion because the spell description says: [the illusion] seems completely real, including sounds, smells, .... Would seems completely real mean that the illusion will be "flinching" when attacked with a ray? Isn't that "real" for an illusion?
- Or maybe the bard controlling the illusion can declare the following action: jump out the cover, start a "conversation" with Xanathar with some nasty insults about his pet fish, get 3 deadly rays as the "response" to that if the Beholder shoots and then "carry on this conversation" by "dodging and taking a hit" and then jumping back behind the cover (because the spell description clearly says that "you can cause the illusion to ... carry on a conversation, for example."). I'd define "carry on a conversation" as "IF the other guy would say A to my illusion, THEN my illusion would respond with B". How is it different from "IF the Beholder would shoot at my illusion, THEN my illusion would flinch and show off as if has hurt me badly"? If "carry on a conversation" is clearly allowed, doesn't it mean that while executing your action to control the illusion you CAN REACT to the changing environment if you've anticipated such events? (changing environment being the Beholder shooting the rays at the illusion)
As a beginner DM, I obviously know that it's an illusion. The party knows that I know, and I don't want to make it look like the Beholder got an "unfair advantage" from the DM because of that. So I have to roleplay the Beholder pretending that he sees a real enemy and should be trying to attack him. On the other hand, I really want to make this encounter balanced and running for 5 turns all over the battlefield, "absorbing" 100% of the Beholder's rays, should probably not be a viable tactic... Where is the happy medium?
UPDATE: Some important context here (on why the Beholder will probably NOT "just point the Antimagic Ray on the target and reveal that it's an illusion"):
Sure, the Beholder has his Antimagic Cone and pointing it at the illusion would've exposed the illusion immediately. But if we'd take a birds-eye look at the whole battlefield, then the most logical tactic for a Beholder would be this:
- Point the Antimagic Cone at the most dangerous spellcasters or on the main target (the wizard carrying the artifact in case of our encounter)
- While the spellcasters are "disabled" and are basically "sitting ducks" - approach them with some melee-fighting minions
- Set a readied action: "if anyone of the main party members shows up anywhere outside the Antimagic Cone - shoot him with the 3 deadly rays"
I don't know how Beholder encounters usually happen for others, but I suspect that this 3-item strategy sounds quite logical for a Beholder in most of the cases. Anyway, this is how it looked for our encounter:
So, the party learned the hard way that the Beholder is smart! He knows every "VIP character" on the opposing side and will shoot anyone of those VIPs with his readied action as soon as any of those folks would show up outside the Antimagic Field. And three rays being shot at one PC at the same time would most likely mean this PC is DEAD in one turn. I'd say that for any party members and NPCs, "being that first guy to take 3 rays for the party" would certainly be suicidal and "out of character". But someone has to be that guy who will take that first alfa-strike on him? Why not make the illusion to take those hits and THEN make a move?
So, the party came up with a plan: create an illusion of one of the VIP characters from a safe place and make it look like one of the VIP characters is stepping outside of the Antimagic Cone and provoking Xanathar to waste his "alfa strike" on this turn and then hiding behind cover at the end of the turn so it will not be revealed in case Xanathar moves his Antimagic cone towards the illusion. So that other party members can safely step outside of the cover in the zone without the antimagic field and safely throw their spells combos against Xanathar without being afraid to get 3 rays right in the face... Then, repeat the same on the next 1-2 turns: the party's combo starts with the illusion showing up and provoking Xanathar to strike it with his 3 rays.
To sum up: there are strong tactical reasons for Beholder NOT to move the Antimagic Cone away from the main targets with their scary spells (Team A) onto a single annoying illusion, but to just "kill it" with rays. Especially if the illusion is a non-spellcaster, no reason to waste Antimagic Cone on a barbarian or a monk... But will the Beholder still be wasting all his alfa-strikes on all of the next turns on the same target?