We were recently introduced to the game Nine Square in the Air by some friends. We decided to try it out at our non-profit camp, so we built our own version. Later on, someone brought it to our attention that the game design may be patented. What do we do now?
9 Square lists two design patents,
Now being Non-Profit and controlled use you might have some option for security, but certainly you have to consult attorney about further use of this game. Alternatively if you have been not given notice stop the use and try alternative of present game.
Further For infringement of design patents
design patent infringement test is not a minute analysis of detail but rather a test that asks whether the overall appearance of the patent and accused designs are substantially same in the eyes of an ordinary observer
if you feel that your modifications are out of the above test then consult a legal expert either to file patent application or get opinion on further use.