I counted 14 + gorilla...but then again, I'm familiar with this kind of experiment.
OTOH, top-notch athletes- Tom Brady, LeBron James, Mike Modano, etc.- all manage to have their passes picked off. Despite their training and awareness, they still have opponents "picking their pockets."
Why? Because, in game terms, observation and awareness are not unaposed skill checks. You don't automatically succeed at seeing things, no matter how skilled you are at being a trained observer within your area of expertise.
As good as you are at noticing things, your opponent has skill at having his intentions being misperceived.
And the Beholder in question? Where was it? Did its rocky appearance sort of blend in with the dark, stony environment of the dungeon, or was it a big floating ball in the forest highlighted by multiple rays of sunlight?
Might be worth talking to larpers and martial artists. To see how often they get "surprised" by enemy combatants who should have been obvious.
Note, this is all different than tha bad guy who is trying to come up from behind (where you obviously can't see).
The scenario you're testing for is can a person in a fight/exploring a dungeon miss seeing an obvious threat (the gorilla in the basketball game).
I guarrantee you, the basketball players all saw the gorilla. They were not hyperfocused on the ball, they were focussed on the entire field, because they had to know where they were, the enemy was, and where their allies were.
OTOH, top-notch athletes- Tom Brady, LeBron James, Mike Modano, etc.- all manage to have their passes picked off. Despite their training and awareness, they still have opponents "picking their pockets."
Why? Because, in game terms, observation and awareness are not unaposed skill checks. You don't automatically succeed at seeing things, no matter how skilled you are at being a trained observer within your area of expertise.
As good as you are at noticing things, your opponent has skill at having his intentions being misperceived.
And the Beholder in question? Where was it? Did its rocky appearance sort of blend in with the dark, stony environment of the dungeon, or was it a big floating ball in the forest highlighted by multiple rays of sunlight?