Please forgive me if this has already been asked. I looked and found no mention of it. When playing the Genius, barring cards/powers that require you to reveal part or all of your hand to someone else, is there any rule saying you have to tell the other players how many cards you have in your hand? I pis...greatly annoyed a friend using this tactic (not revealing, I mean) so that he couldn't keep track of my potential victory through card collecting. I could find nothing in the rules to deny me this tactic, but would really like an official adjutication.
Thanks in advance.