Card games

Card games like especially – but not only – poker are still very much the thing in the post nuclear wasteland. This is the skill used to play them.
To stay with the poker example: those who can bluff or see through a bluff, have bonuses – who can't, has handicaps. A good empathy skill might help.
There are however a few, already defined rules under gambling games.

The starting value is: 2 * C + 2 * L