What obstacles get in the way? How do they handle those who won't play the game well and who are happy to lie/cheat/trample all over everyone else in life?
Do you have a character who could be described as the referee and whose judgement is final? Do they act justly and play the game well?
At the end of your story, what is the result? Have the cheaters prospered or have the characters who played the game well got their reward and won?