# Fischer Random Chess (Chess960)

by Scott Brueckner

Fischer Random Chess (also called Chess960, Fischerandom Chess, FR Chess, or FullChess) is a chess variant created by Grandmaster Bobby Fischer. His goal was to create a chess variant in which creativity and talent would be more important than memorization and analysis of opening moves. To accomplish this, the positions of the major pieces are "randomized" before each game. In Fischer Random Chess, there are 960 possible starting positions, as opposed to the single starting position in traditional chess.

You may find an understanding of Algebraic Chess Notation helpful as you read this.

## 1) Rules of the Game

The rules for Fischer Random Chess are exactly the same as traditional chess except for:

Because of the large number of starting positions, play is much less predictable than traditional chess; however, the same opening fundamentals apply (for example, protect the King, control the center squares, develop your pieces rapidly starting with the less valuable pieces, etc.).

Be advised that some starting positions have unprotected Pawns that may need to be dealt with quickly.

## 2) Starting Position

### 2.1) Rules for Setting up the Board

• Place all of the Pawns on their traditional home squares (rank 2 for White and rank 7 for Black).

• Place all remaining White pieces randomly in the back row (rank 1), observing the following rules:

• The two Bishops must be on opposite-colored squares.

• One Rook must be to the left of the King and the other Rook must be to the right of the King. (The Rooks don't have to be right next to the King, but the King must be somewhere in between the two Rooks.) Note that this means the King cannot be on a1 or h1 since there has to be room for the Rook.

• Set up Black's major pieces equal-and-opposite to the White pieces. For example, if White's back row is Ra1, Bb1, Kc1, Nd1, Be1, Nf1, Rg1, Qh1, then Black's back row will be Ra8, Bb8, Kc8, Nd8, Be8, Nf8, Rg8, Qh8, as shown in the figure below:

 a b c d e f g h 8 7 6 5 4 3 2 1 One of 960 Possible Starting Positions

### 2.2) Randomizing the Starting Position

I've written an on-line Computerized Shuffler that generates random starting positions. If you use it, I recommend that you leave it on your computer screen as you play your game because it also shows the valid castling moves (which you may find helpful).

You can devise your own randomization technique if you like. I've read about methods using dice, coins, cards, etc. You could even draw pieces out of a bag. Basically, anything that ensures a random sequence of pieces will work. Of course, you must obey the placement rules listed above.

## 3) Castling

### 3.1) Castling Concepts

Because the starting positions of the King and Rooks are variable, castling is somewhat different in Fischer Random Chess. It may seem confusing at first, but it's really quite simple. The cardinal rule is:

After castling, the King and the castling Rook end up on the same squares as they would in traditional chess.

In traditional chess, we usually think of castling queen-side or king-side, but these terms don't work so well in Fischer Random Chess since the Queen may be on either side of the King. Therefore, I think of castling a-side or h-side. (Algebraic notation is going to come in very handy here.)

Consider the following board that shows the starting positions of the Kings and Rooks in a traditional game...

 "a-side" "h-side" a b c d e f g h 8 3 4 8 7 7 6 5 4 3 2 1 1 2 6 5

The following rules apply to castling in Fischer Random Chess regardless of the starting position of the pieces. (Note that these are the same rules as for traditional chess.)

a-side castling:

• Is queen-side castling (0-0-0) in traditional chess.

• For White:
• The King castles with the Rook to the King's left (looking from White's side of the board).
• The King always ends up on c1 ("1" in the figure above).
• The Rook always ends up on d1 ("2" in the figure above).

• For Black:
• The King castles with the Rook to the King's right (looking from Black's side of the board).
• The King always ends up on c8 ("3" in the figure above).
• The Rook always ends up on d8 ("4" in the figure above).

h-side castling:

• Is king-side castling (0-0) in traditional chess.

• For White:
• The King castles with the Rook to the King's right (looking from White's side of the board).
• The King always ends up on g1 ("5" in the figure above).
• The Rook always ends up on f1 ("6" in the figure above).

• For Black:
• the King castles with the Rook to the King's left (looking from Black's side of the board).
• The King always ends up on g8 ("7" in the figure above).
• The Rook always ends up on f8 ("8" in figure above).

Some situations are a little odd. For example:

Game starting position:

 a b c d e f g h 1

After a-side castle:

 a b c d e f g h 1

We normally think of an a-side castle as a castle to the left (for White), but notice how both pieces moved to the right in this case! Odd, but correct. The rule states that after White castles a-side, the ending position is always Kc1, Rd1.

It may help to play with my Computerized Shuffler. For each board it generates, it displays all of the valid castling moves. You can keep generating new boards until castling makes sense.

### 3.2) Castling Conditions

The conditions under which you can castle are essentially the same as in traditional chess:

• You can only castle once per game.

• The King and the castling Rook must not have moved before in the game.

• The King cannot castle out of, through, or into check.

• All of the squares between the King and castling Rook must be vacant.

• All of the squares between the King's initial and final squares (including the final square), and all of the squares between the Rook's initial and final squares (including the final square) must be vacant except for the King and the castling Rook. In other words, neither the King nor the Rook can "jump" any pieces except each other.

• Castling cannot capture any pieces.

### 3.3) Castling Oddities and Etiquette

In some starting positions, the King or the Rook (but not both) do not move during castling. In other situations, both the King and the Rook will move, sometimes in the same direction. (They will always switch sides, though.)

I've read some analyses of these different castling situations along with recommended procedures for actually making the moves (e.g., which piece to move first, etc.), but I think it's all bullshit. In my opinion...

As long as it's legal to castle (see section 3.2), just put the King and the Rook on the correct squares (see section 3.1) and don't worry about how they move (or don't move) to get there.

Because it's sometimes not apparent that you're making a castling move, it's considered good etiquette to announce the fact that you're castling.

In some starting positions, some squares can stay filled during castling that would have to be vacant in traditional chess. For example, after a-side castling, it's possible to have a, b, and/or e still filled, and after h-side castling, it's possible to have e and/or h filled.