Since I began teaching Macroeconomics in 2011 I've instituted a tradition of shutting down the class one day per semester* to play economics board games. All of the games, being economic in nature, implicitly convey opportunity cost. Over and above that, the games can also teach about . . .
Comparative advantage and specialization (Pandemic)
The importance of investment to productive possibilities (Ticket to Ride, Agricola, Settlers of Catan)
The value of trade (Settlers of Catan)
Injections and stimulus measures (Kuhhandel)
I take great joy in watching 12th graders spend an hour or so learning a game they've never even seen, get involved in disputes over livestock and cars, and walk out of the room figuring out how they'll pool their resources to buy their own board to play again.
*Usually, at students' request, there's a 2nd day near the end of the semester.