I wonder about the playtesters Tom mentioned. Did they playtest for actual money? If yes, how much? And did they know each other? Because I believe it makes a world of difference. Five strangers, much more likely to screw the others. Not playing for actual money, or not playing for much money? Much more likely to not do an even split, as a joke that wouldn't matter. With so much money involved, you would feel really wrong not being fair and honest with that briefcase.,(reply>), They played for some money, and the results were much the same except for Mike's ingenious "20% guarantee" strategy at the end.