(defmacro let-game ((game player) &body body)
  `(let* ((player (gethash ,player ,game))
          (opponent (gethash (not ,player) ,game)))
     (declare (ignorable player))
     (declare (ignorable opponent))
     (macrolet ((hand (p) `(gethash "hand" (gethash ,p 'game)))
                (deck (p) `(gethash "deck" (gethash ,p game))))
       ,@body)))

(let-game (x t) (print (deck t)))