Just as chess has changed over the centuries that it has been played, there are people who try to add new features or ideas to chess even now. Sometimes this is just a minor rule change to make things interesting, but sometimes there are whole new ideas that are proposed that will modify chess so substantially that it essentially is a whole new game to be played. The following are some chess variants to be considered if you want to experiment with alternative ideas for playing chess:
Many other chess variants can be found on Wikipedia.
- Random Opening Chess
- Bug House and Crazy House
- Crazy House (see Bug House)
- Chinese Chess or Xiangqi
Fairy chess 
It is possible to invent a piece that moves according to any defined set of rules. In fairy chess, pieces are typically divided into three categories: leapers, riders, and hoppers.
A leaper moves directly from one square to another, regardless of the position of any other pieces on the board. In ordinary chess, the knight is a (2,1) leaper: it moves one square horizontally and two squares vertically, or vice versa. The king is a hybrid (1,0) and (1,1) leaper: it moves to any adjacent square.
Fairy chess has pieces called camels and zebras: these are long-range leapers like knights, except that they leap (3,1) and (3,2) respectively. Note that a (3,1) leaper, like a bishop, always stays on squares of the same color, but a (3,2) leaper, like a knight, always moves to a square of the opposite color.
A rider is a leaper that can make multiple leaps in the same direction on the same move. In ordinary chess, the bishop is a (1,1) rider: it can move to any square diagonally, no matter how far away it is, as long as there is no other piece blocking the diagonal line. Similary, the rook is a (1,0) rider. The queen is a hybrid (1,1) and (1,0) rider.
A special fairy chess rider is the nightrider or knightrider. This is a knight that can make consecutive knight-hops in the same direction on the same move.
A hopper is a piece that moves in a line while hopping over another piece. There are no hoppers in ordinary chess, but the capture rule in checkers is a kind of hop: the capturing piece jumps over the opponent's piece, which is then removed from the board. Also, the cannon in Xiangqi is a hopper. In fairy chess, a hopper may or may not be restricted to jumping over pieces of one color or the other; and the piece that is jumped over may either stay on the board or be removed, depending on the rules for that particular hopper.
The prototypical fairy chess hopper is the grasshopper. It moves in any direction, like a queen, but it can move only by hopping over another piece, and it lands one square beyond that piece. The piece that is jumped over is not removed from the board; however, a locust is a special type of grasshopper, which captures an enemy piece over which it jumps.
T. R. Dawson, one of the most prolific chess composers of all time, defined the concepts of fairy chess in the 1930s, and produced many problems using invented pieces such as the nightrider and grasshopper. Fairy chess has become a popular domain for chess composing and solving, especially because it offers a level of creativity that is sometimes hard to find in the more thoroughly developed areas of traditional chess composition.