Quantum chess

Chess is a well-known strategy board game that is played around the world. The rule of chess are simple, but there are many possible variations. People have been studying chess for ages, but there's still more to be explored.

There are actually two types of the chess game that exist at this time. The version that most of the people know is the original version. The other version that fewer people know is called "quantum chess". Quantum chess is a variation of the original chess game, it includes some features of quantum phenomena in the game. The rule of quantum chess is very similar to the original chess, every piece moves exactly the same way as it does in the original game. What's different in quantum chess is that every piece except pawn can do the "quantum move". When a piece does the quantum move, it has 50%chance to reach a position that is two standard move away. After a piece does one quantum move, it exists in the superposition. In other words, that piece has two possible states, one is that it locates at two standard moves away, the other is that it sits at the original position. A piece can do more than one quantum move so there can be more than two possible positions for one piece. This rule adds more complexity into this game because when a piece does the quantum move, it may be a place that is two regular moves away or not moving at all. What is interesting is that the position of the piece after the quantum move is decided by pure chance, so there's no way that players can know the real position of the piece unless they trigger the "measurement". In quantum chess, two pieces cannot occupy the same space, when a piece is moved to a square that is occupied by another piece that is not in the superposition, it will capture that piece, if a piece is moved to a square that is occupied by another piece that exists in superposition, it will trigger the measurement, the system will measure the position of the piece that is in the superposition, the system will measure the position of that piece. After the measurement, the real position of the piece may be revealed, depending on whether there is more than one possible position of the piece after the measurement. The quantum feature of the quantum chess gives the chess game more variety, making an already complex game more complicated. To win in quantum chess, one must kill the king. This is different from the original chess. In the original chess, one wins the game by giving checkmate or making the opponent resign. This rule gives players more possible ways to prevent from losing the game. Since the king can also do the quantum move, players can move the king with quantum moves multiple time to make the king exist in multiple places at the same time. By doing so, players can make the task of killing the king hard. Unless the all the possible locations of the king is eliminated, there's no way to know the king's real position, let alone killing it.

This variation of the chess game is very interesting. It is more complicated than the original game, so it is hard to be mastered. This game can also let people understand the basics of the quantum mechanics because the special features of this game are extracted from the quantum phenomena. Thanks to, Chris Cantwell, the physics Ph.D student at the University of Southern California, we are able to play this interesting game and appreciate the beauty of the quantum mechanics.