I've seen people play cards/games all over the ship. As long as the ship staff is not involved then you can play where ever you like.
Life is too short to let the ship of your dreams sail without you.
Carnival Destiny Feb. 2006
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Royal Caribbean Grandeur of the Seas Feb. 2008 The DTW & MsBJ tour
Carnival Valor MsBJ and Dina Feb. 2009
Carnival Glory MsBJ and Dina Feb. 2010
Carnival Dream MsBJ and Dina Feb. 2011
As posted by Dina, YES, passengers play all over the ship (cards, dominos, board games, trivia, etc.).
We sail on =X= mostly, and heck, some of the pax bring out their dominos and dice to the Aqua Spa / Thallossotherapy area (even though there are signs asking for quiet to keep the atmosphere spa-like)...but many don't.
So many quiet, unused areas of a ship. You guys will probably not have any difficulty in finding your onw niche' area of the ship!