For those of you suggesting that the beholder should be allowed to “fire blind”, I think that’s an easy solution but one that can potentially lead to players saying “That’s not fair! Why can’t I ‘fire blind’ with my spells that require line of sight too?”
“You can, if you select ray spells like
ray of frost & ray of enfeeblement. Did you select those spells?”
I know that’s a very legalistic / tongue in cheek answer (why are beholder’s Eye Rays called
rays but don’t conform to common text shared by “ray of” spells? Geee), so that would be my wink wink response…
…but I think that sort of player objection really is more a play style & house rule conversation.
For example, if you have players who believe “the monsters can do what their stats say, and only what their stats say, not subject to on the fly GM whims”, then that’s something the GM needs to know and have a conversation about. Personally, if players told me that, I’d let them know I’m probably not the right GM for them.
Similarly, if a group of players expect PCs and monsters to conform to the same design rules, that’s something the GM really needs to know. Because the only time in D&D’s history where that was true was 3e, which suggests to me that that group might be better served playing 3e or Pathfinder.
Or another example would be a player wanting to run a blind PC spellcaster - does your group prefer that player need to sort thru which spell descriptions omit “a creature you can see”? Or do they prefer to give that PC some leeway? Or do they prefer for ALL casters to have some leeway when it comes to D&D’s legalese spell descriptions?
When I run for a group hasn’t had those conversations (eg. one-shots with new folks), I will often answer the “why can’t my spellcaster do xyz?” questions with “If you upcast it by so-and-so levels, I’ll allow it.” That’s a great multipurpose tool to have in your GM toolbox to keep things moving forward and defuse certain player types.