This is the classic "8 Queens" puzzle - the splash screen gives directions. Very message driven, with some coordinate math having to do with translating mouse clicks into chessboard square coordinates ((0,0) is upper-left). Started out as a simple "could-I-do-this?" hack, but then my stubborn, persistent side took over. *Click the green flag first to make sure things work properly! Improvements: Variables like Queen0Visible, Queen0X, Queen0Y do not need to be global - they ought to be local to their sprite. Have fun, and please use whatever you find useful! (though a citation would be appreciated!)