This is a nice False Equivalence as well. In one case you have a knight doing something that has nothing to do with an attack and has no effect on mechanics whatsoever, and on the other side you have a situation where you are setting up mechanics to allow Counterspell. They are not the same. One is fluff(knight example) and the other is adding to the eye ray rules to change Beholder eye rays in order to allow Counterspell to work.
So did you intentionally make a false equivalence, are you recognizing that I was right in describing it as such, or is the “as well” in your reply just imprecise language?
Anyway, describing what a monsters abilities look like isn’t adding mechanics, regardless.
Edit: and the Xanathar's has nothing to do with what I have been saying. This is from the Sage Advice.
"If a sorcerer casts a spell with only verbal or somatic components using Subtle Spell, can an opponent use counterspell against it? If a spell that’s altered by Subtle Spell has no material component, then it’s impossible for anyone to perceive the spell being cast. So, since you can’t see the casting, counterspell is of no use."
So you can see from PHB only, if you can't see components being used, it's not perceivable. You are adding flashes of light and such that don't exist.
Its odd to have to say this, but…a beholder, unless homebrewed, isn’t a sorcerer casting a spell with subtle spell.
Deciding whether the eyestalk moves, or focuses on a creature in a noticeable way, or any other indicator of what it’s about to do, is entirely, 100%, unequivocally, up to the DM.
This seems simple to resolve, just quote from the beholder MM entry the description of its spellcasting such that counterspell can be adjudicated?
Could do, sure. But what a monsters abilities look like is…inarguably up to the DM.
It’s also just very strange to see a “DM has unlimited authority” poster arguing that it’s against the rules to…rule a way they don’t agree with as part of adjudicating a houserule.
If one houserules that Counterspell can counter any ability which replicates a spell effect, then one is going to have to make some best judgment calls about how a given ability would be written if the houserule were the RAW, so even if I were wrong about the rules in this case (and I’m not), it
wouldn’t even matter!
It was weird as hell for max to even try to tell another poster their houserule doesn’t work because RAW says XYZ in the first place.
