Venice Connection

This is a two-player river tile laying game. The object is to complete the canal in a loop. There are 16 identical tiles in the game, each with a straight section of canal on one side and a bend on the other. All the tiles are available for either player to use.

If one player notices that the canal is now impossible to complete during the game, they say "impossible" to the challenged player (who placed the last tile), who now must try to finish the canal alone. If the canal is completed the challenged player has won, if not, the challenger has won!