ChessXp

ChessXp is the result of a plausible set of rule adjustments that would make chess playable on a 10x10 board, while preserving the minimalist design concept of the original game. It should simply feel like Chess when played. And, the games played so far suggest it does. Classic vibe, new adventures ...

If you want to play ChessXp, you can do it on chessxp.com.

The rule adjustments introduce a non-random next piece, faster pawns and an extended start position.

Setup

The board is extended to 100 (10x10) squares. The files are labeled with the letters a-j, the ranks with the numbers 1-10. The lower right square of the board is black.

The default setup is FRNBQKBNRF. The F stands for the falcon piece. Description below.

This setup is choosen to provide maximum flexibility regarding the pawn structures that can arise in a game. Means, the pawn structure should be mainly be a choice of the players and not be dictated by the setup. The lesson from Chess960 is here that this flexibility is determined by the position of the bishops and the queen.

The suggested setup is the only possible one if the following rules are applied:

- All pieces can be developed by moving only the two central pawns.

- There are no unprotected pawns in the initial position.

- King and queen are centrally placed.

Pieces

One new piece is introduced. The falcon is basically a big knight, the logical next twin piece after bishop, knight and rook and complementary to these regarding the squares it controls. While the knight reaches all squares that are part of the second circle around a given square and cannot be reached by rook or bishop, the falcon has the same ability for the third circle. The following diagram shows how the falcon fits into the picture:

The falcon in a separate diagram:

Like the knight, the falcon can "jump over" all other pieces (of either color) to its destination square.

Rules

Pawns

The original rules of Chess apply, except a modified pawn movement:

Pawns can move up to three steps forward when placed the initial square.

Up to two steps forward when placed on the third, fourth or fifth rank.

One step forward when placed on the sixth rank or higher.

This means a pawn can reach the promotion field within five moves, which is the same number of moves as in classical chess:

Adjusting the pawn speed to the bigger board seems necessary to keep the dynamic spirit of the original game that includes fast confrontation and a broad spectrum of possibilities for piece sacrifices.

En passant capturing is possible each time a pawn passes an enemy pawn by moving more than one square forward in one move. The following example shows possible captures after the white pawn moved three squares forward:

Castling

The castling rules are the same as in classical chess, but let's state it for clarification: The King moves two squares towards the rook, rook jumps over. Thus, after 0-0 the king and rook are located on h1 and g1, after 0-0-0 on d1 and e1.

Notes

Important design elements of classical chess ChessXp incorporates

- Two single pieces: The key piece and the strongest piece. The latter has the same move pattern as the key piece but with unlimited range.

- Three (four) pairs of twin pieces that are complementary to each other.

- Pieces with ambiguous routes to their destination squares (knight, falcon) can move directly to these squares regardless if one or all routes are blocked.

- Pawns get slower once they pass a certain rank number.

- The game is played on a square board.

Game dynamics

10x10 should faciliate gambits and sacrifices in general, since one pawn unit represents a lower fraction of the complete material stock.

It also should be noted that the knight, despite suffering from longer routes on a bigger board, also benefits from it, since there are fewer situations where this piece is located near the border and therefore controls on average more fields than in classical chess.

Some notes regarding the building blocks used for this chess variant

There are obviously other variants that use a 10x10 board.

The concept of minimizing the necessary rule adjustments compared to classical chess and to extend the b, n, r line with the next logical piece was used by George Duke in his Falcon Chess, resulting in a 10x8 board, a non-leaping falcon and a "r, n, b, f, q, k, f, b, n, r" setup.

The leaping falcon is also known as bison and has apparently been used as early as 1974.

The 3, 2, 1, 1, 1 pawn movement might be a completely new approach.

Author

Invented by Uli Schwekendiek in Berlin 2019.

Again ;-) If you want to play ChessXp, you can do it on chessxp.com.

Last revised by Uli Schwekendiek.