Specifically, keep track (maybe publicly, on the board) of who got how many points, and have everyone write down their points on their card. Then gather all the cards back, shuffle them, and have people randomly select a card. Then run the scenario again, this time with initial inequality, and find out the results. This second round of points is added to the first round of points for each person, and the final number of points factors into their grades.
Will everyone ostracize the selfish people? Or will they emulate them? Will their habits change when they are "born" into inequality?
Don't tell them that you're going to run it again until you do.
For anyone who runs these games, I'd love to get the name-removed results!