As in Football (Soccer) where you can show a player the yellow or red card, the idea is that we can use the same concept …but with a new twist.
Below are scanned copies of the 64 cards included in the Creative Whack Pack created by Roger von Oech. Here you can either use the cards for introspective purposes, or maybe show other players a card. A phase two of this concept might include a way to keep score, but then a conventional wisdom factor would have to be built into the equation.
Along this same vein, Brian Eno and Peter Schmidt put together a card set called Oblique Strategies, which uses the concept of random selection as a source of inspiration.