Ideally, you abide and enjoy the social contract when playing middle-weight board and card games. Bring to teach and learn to play.
Somewhere in the dead-center of the board and card gaming universe are folks who want the challenge of learning and playing Euro and "Ameritrash" board games and card games. Those folks have a long and varied list of games they wish to play. When a game calls for it, those folks don't mind managing luck, being tinkered by or tinkering with others, and accepting victory or defeat with aplomb. When a game calls for it, those folks don't mind relying on independent strategy involving little or no chance, more complex rules, and intense play. Somewhere near that center are folks who embrace the social nature of playing games and act accordingly.