Reflecting on something I heard about Hillsborough County (Tampa, FL, mostly) diverting kids from after-school mischief via a chess club, I remembered a chess variation from my own youth called 'Kriegspiel'. Kriegspiel is a German word meaning "war games", and it's unlike any other form of chess you've ever seen.
Whereas ordinary chess (and even Wizard's chess) is played by two players, one board, and one set of pieces, Kriegspiel needs three boards, two sets of pieces, and a referee.
The players sit with their backs to the center board (which has a full set of pieces), each with a board containing only the pieces of their own color. As each player makes a move, the referee replicates that move on the center board. Usually the referee merely announces "white/black has moved". Occasionally, this is followed by "capturing" or "giving check". Sometimes the referee announces "illegal move" because that move cannot be made on the center board, as when an attempted move passes through an occupied square or moving the piece exposes a check.
When a player captures an opposing piece, that piece is removed from the opponent's board. "White has moved, capturing." White knows that a capture has taken place but not which piece. Black knows which piece was captured, but not which piece did the deed or where it came from. Should I recapture? Is it worth risking that Knight since it might also be immediately recaptured?
As with standard chess, the game ends when checkmate or stalemate occurs, but with Kriegspiel the game also ends when any player leaves their board or sees the center board. Of course, the audience, if there is one, must be silent for fairness. No groans or laughs may be allowed to give away bad moves or good.
Some referees will be more specific with their comments, e.g.: "Black has moved giving check on the long diagonal". Such announcements may be made for a lower-ranked player but not her higher-ranked opponent. That's local custom and agreed before the match.
While it sounds terribly odd, most games of Kriegspiel are hilarious to watch, and it's a real chore for the audience not to give away valuable information. The games are also fairly educational because we often do not understand how much value information has until we don't have it. Because of this, it's a good idea to have someone transcribing the game so that it can be re-played for the essentially-in-the-dark participants after the game concludes.
Try it; you'll like it.