Introduction

Chess on a really big board, also known as four-board chess, is a very large variant played on a 16 by 16 board.

History

Chess on a really big board was invented by notable chess variant designer Ralph Betza sometime in 1996 and was derived from one of his ideas for a three-dimensional variant. Betza noted that an 8 by 8 by 8 3D variant would have a board of 512 squares, more than any large variant then invented, and such a board would be difficult and unwieldy to put together. On the other hand, a 2D 16 by 16 board has only 256 squares, half the number of the 8 by 8 by 8 board, and can easily be put together by combining four standard chess boards.

Rules

Chess on a really big board is played on a 16 by 16 board with 32 pieces per player. The six standard chess piece are used, as well as six new fairy pieces. The new pieces move as follows:

• The FD () may either step one square diagonally or jump two squares horizontally or vertically.
• The WFA () may either step one square in any direction or jump two squares diagonally.
• The superknight () may jump in an "L" shape like a knight, but with more range. It may make a two-then-one jump like a knight, a three-by-one jump or a three-by-two jump.
• The archbishop () combines the powers of the bishop and the knight. It may slide diagonally like a bishop or jump in an "L" shape like a knight, but not both in one move.
• The chancellor () combines the powers of the rook and the knight. It may slide horizontally or vertically like a rook or jump in an "L" shape like a knight, but not both in one move.
• The rose () may make consecutive knight jumps along an octagonal path. It begins its move by jumping like a knight - after it lands it may either stop or turn one knight direction clockwise or counterclockwise and make another jump. After it lands for the second it may either stop or turn again in the same direction and make another jump. As the rose keeps doing this it traces an octagonal path, as shown below:

	a	b	c	d	e	f	g	h	i	j	k	l	m	n	o	p
16																	16
15																	15
14																	14
13																	13
12																	12
11																	11
10																	10
9																	9
8																	8
7																	7
6																	6
5																	5
4																	4
3																	3
2																	2
1																	1
	a	b	c	d	e	f	g	h	i	j	k	l	m	n	o	p

Demonstration of the rose's movement. The rose begins its move by jumping from its initial square to one of the squares marked with a 1. After that it may turn either clockwise or counterclockwise and travel to a square marked with a 2. Then it travels to a square with a 3, then a 4, then 3 again, then 2 again and then 1 again. If the player wants to they may move the rose along the entire path so that it lands back on its initial square - this effectively allows a player with an unblocked rose to pass a turn if necessary.

Some notes:

• The rose may not change direction mid-move - once the player has chosen for the rose to travel clockwise or counterclockwise, that is the direction the rose must travel for the entire move.
• The rose may jump over any pieces in the way like the knight, but all of the squares in the path must be free of friendly pieces.
• If one of the squares on the path is blocked by an enemy piece the rose may capture it, but that is the square the rose must stop on.

The pawns may move between one and six squares with their initial move, but after that they may only step one square at a time. An en passant capture may be done if an enemy pawn could move diagonally onto any square the pawn crossed over.

A pawn is allowed to promote to any of the new fairy pieces alongside the usual promotion options.

When castling kingside, the king moves from the i-file to the n-file, and when castling queenside the king moves from the i-file to the c-file. After the king moves the rook moves to the other side of the king.

The fifty-move rule has been extended to a 100-move rule - a player must allow 100 moves to elapse without a pawn move or capture before they may claim a draw.

Sub-variants

This chess variant does not have any notable sub-variants.