Hectochess

Hectochess is a game inspired by my earlier game Yangsi. The idea for the game came about when I realized that Yangsi had 4 too many pieces to be played with just a 10x10 chessboard and 2 mismatched chess sets. I decided to make a similar game that could be played using said equipment. The result was Hectochess. The idea was not to make an entirely new game, but rather to make a more accessible version of Yangsi.

Play Hectochess with others or against an AI via ChessV

Play Hectochess with others or against an AI via Ai Ai

Play Hectochess with others or against an AI via Jocly

• Jocly implementation by François Houdebert

Play Hectochess against others via Game Courier

Setup

An interactive diagram has been provided (The Javascript source code was written by H. G. Muller) to make it easier to understand how each piece moves. The diagram uses pieces from the Musketeer Chess Board Painter.

First rank

• a1 Archbishop (BN)
• b1, i1 Wizard (FC)
• c1, h1 Leo (mQcpQ)
• j1 Marshall (RN)

Second rank

• a2, j2 Rook (R)
• b2, i2 Champion (WAD)
• c2, h2 Knight (N)
• d2, g2 Bishop (B)
• e2 Queen (Q)
• f2 King (KisO3isO2)

Third rank

• a3-j3 Pawns (ifmnDfmWfceF)

Pieces

Upside down pieces are pieces from a second Chess set whose pieces are visually distinct from the first Chess set.

King	The King moves one space in any direction but not into check. It moves the same as it does in Chess but castles differently.	Queen	The Queen moves as a Rook or a Bishop, the same as it does in Chess.
Marshall	The Marshall moves as a Rook or a Knight. It is a popular piece in many Chess variants, dating back centuries, even before Chess as we know it today came into existence.	Archbishop	The Archbishop moves as a Knight or a Bishop. It is a popular piece in many Chess variants, dating back centuries, even before Chess as we know it today came into existence.
Rook	The Rook slides across the board in a vertical or horizontal direction, as it does in Chess.	Bishop	The Bishop slides across the board in any diagonal direction, as it does in Chess.
Knight	The Knight leaps to a space one file and two ranks away or two files and one rank away, as it does in Chess.	Pawn	The Pawn moves one space vertically forward without capturing, and it moves one space diagonally forward to capture, as it does in Chess. It can also move two squares forward on its first move and capture by en passant a Pawn that has just made a double move like it does in Chess. However, it is subject to different rules of promotion.
Champion	The Champion leaps two spaces in any orthogonal or diagonal direction, or one space in any orthogonal direction. It is a compound of the Alfil, Dababbah, and Wazir. It was introduced in Omega Chess, and it moves the same as it does in that game.	Wizard	The Wizard moves one space diagonally or leaps to a space one file and three ranks away or three files and one rank away. It is a compound of the Ferz and the Camel. It was introduced in Omega Chess, and it moves the same as it does in that game.
Leo	The Leo moves as a Queen but must hop over an intervening piece to capture.

Rules

Aside from differences in the board, pieces, and setup, Hectochess is played like FIDE Chess with the following differences:

Pawn promotion: When a Pawn reaches the last rank, it must promote to another piece of that player's choice: a Queen, Marshall, Archbishop, Rook, Champion, Leo, Knight, Bishop, or Wizard of the same color. It cannot promote to King or another Pawn.

Castling: When castling, a King may move two or three spaces toward the Rook when it castles, with the Rook leaping over the King to the closest space the King has just passed over, so that King and Rook end up adjacent to each other. The usual castling conditions from Chess apply. A King may not castle from or through check, all spaces between the Rook and King must be empty, and neither piece may have moved before.

64-move rule: The 50-move rule from Chess becomes a 64-move rule in Hectochess. Similarly, the lesser-known 75-move rule from Chess is a 96-move rule in Hectochess.

Notes

Other than the difference in the setup and the fact that the Cannons and Vaos have been replaced by Leos, Hectochess uses the same rules as Yangsi. I replaced the hoppers from Yangsi with Leos because I wanted to include their moves but I only had one other piece type available due to my objective of making it playable with two mismatched chess sets.

Game Courier Tournament 2019

Hectochess was selected by Greg Strong as one of the nine games to be played in the Game Courier Tournament 2019. Hectochess was played in Round 3 of the tournament, along with Symmetric Chess and Metamachy.

On a side note, Hectochess is the only third round game in this tournament which already had presets with full rule enforcement and display of legal moves by the time the first round began. At the time Fergus Duniho was working on rule enforcement for the presets, which are now finished. The reason Symmetric Chess and Metamachy were placed in the third round was to give Fergus as much time as possible to complete the presets. As for why Hectochess was placed in the third round, that's just how it played out.

Featured Variant

Hectochess was the site's featured variant for the month of November 2023. At the time, Fergus was running low on eligible games to feature, and it was the best candidate for the title in his eyes.

Similar Games

• Yangsi
• Ryugi

Last revised by A. M. DeWitt.