I think I like the idea of changing how you are charged for playing games. Maybe have a small fee for starting a game. I'm thinking 75 crystals might be appropriate.
Well, you could have them initiate the game first you can get an estimate of what the payout will be & then charge a % of that....
I'm not really sure how stealing would work in this case. Otherwise with patience you could easily strip someone of all their money a handful of crystals at a time.
There could be a frequency modifier, the more you steal from one person the more likely it'll be that you are caught. How often can you accidently "bump" into someone?
We could take this a step further and apply it to all games. Instead of X amount of games, there could be a "fatigue" factor where if you just play games for an hour eventually your arm will start to get tired from wrestling or darts, and add on a handicap of say -2 to STR, so that it'd force you to take a break, like say a relaxing walk out in the wastelands...
In any case I brought up the game limit for the new breed of "interactive multiplayer games" that are now possible. The games that are currently in the gaming room I don't consider to be truly interactive, because I could be buying supplies while someone's "arm wrestling" me.