These are variants of the game Turn Off (standard Zillions game) in which the patterns in which lights turn on or off correspond to the moves of royal chess pieces. In the King version, for example, when a light is clicked, that light plus the lights on all adjacent squares -- the squares to which a King could move -- change state. In the Queen version, all lights in the same row, column, or diagonal change state. And so on for the Rook, Bishop, and Knight.
 
The difficulty of the games varies dramatically. The King variants take only four obvious moves to solve, whereas the 5x5 Knight variant is too difficult even for Zillions to solve. The number of moves for the quickest known solutions for each variant are provided in the strategy section, along with an analysis of solutions to certain variants.