The basic concept is that the students work in partners and create a game that is probability based. This automatically rules out many games that are skill based (throwing darts or basketball tosses) unless they can prove its probability based. Next the students brainstorm ideas from games they have already seen from fairs and generate their own ideas. I almost always make students generate their own ideas and proposals before I put them in partners or groups. They have to come to the table with something or they work alone. (This creates accountability and those students who just can't complete assignments and now won't be another student's problem but I can work with them in a smaller group with other similar students). While they come up with their game concept, I begin teaching probability of single and two events. The criteria I give them has them create a game where they have a minor prize and a major prize. I usually give them a general rule of minor prize should be around 1 in 5 and a major prize around 1 in 20. This gives them a sense of how they need to create the game. Many games have 2 stages (or events like a plinko board they may have to hit the winner twice for a major once for a minor) while others just make one event with different options (for example the classic choose a rubber duck from the pond. only 1 of the 20 is major while 4 have minor). The figure out the theoretical probability of their game and build it. It helps to have many decks of cards and lots of dice around because students use them. The creativity of the games can be quite amazing just as much as it can be underwhelming. I have had the students bring in prized that they will give away, or I have collected money and bought the prizes myself so that all prizes are equal (therefore people don't choose a game to get a better prize), or one year I had some PAC money that I was allowed to spend and put it towards the prizes.
