I'm more concerned with the Illithid dialog checks that you can pass or fail.
Im quite honestly not sure there even is any ...
Illithid choices i remember are easy win no matter what. O_o
When you see this message...
*The mark glows, but you feel nothing in response. Your illithid power is beyond reach until you rest.*...that's because you failed the Illithid dialog check. The check is simple: have you used the tadpole power yet? You pass if you haven't and fail if you have.
I'm not aware of any Illithid
dialog checks that require a dice roll.