The Chess Variant Pages

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This page is written by the game's inventor, Fergus Duniho. This game is a favorite of its inventor.

Voidrider Chess


Voidrider Chess is named after the Voidrider, a supernumerary piece created especially for this game. A Voidrider rides through the void, this being off-board space within the play area. The distinguishing features of this game are the presence of gaps within various ranks and files, and the ability of each piece to move spaces into the gaps, thereby rearranging the location of gaps and the shape of the board. The Voidrider is a new piece, designed to take advantage of these gaps. It can move spaces through the void more quickly than other pieces, and it can traverse gaps while other pieces remain blocked by them.

I began to conceive of this game after I drew several 43-square boards on graph paper. I found one that was more symmetrical than all the rest, and I began getting ideas for this game after I drew that board. Inspiration for Voidrider Chess came from my own Wormhole Chess, Jim Aiken's Amoeba and 8-Stone Chess, Andrew Bartmess's Star Trek Tridimensional Chess, and Jonathon Whittle's Magician Chess. Amoeba, Tridimensional Chess, and Magician Chess all move spaces. Voidrider Chess most closely resembles Tridimensional Chess in this respect, since a player must occupy a space to move it. The Voidrider is somewhat inspired by the Magician in Magician Chess, which was the one piece in that game that could move spaces, though the Voidrider is a very different piece. The Voidrider's ability to traverse gaps was borrowed from Wormhole Chess, where every piece had this ability.


       +---+           +---+      
9      | v |           | v |      
8  | r |:n:| b |:k:| b |:n:| r |  
7      | p |:p:| p |:p:| p |      
6      |:::|   |:::|   |:::|      
5      |   |:::|   |:::|   |      
4      |:::|   |:::|   |:::|      
3      | P |:P:| P |:P:| P |      
2  | R |:N:| B |:K:| B |:N:| R |  
1      | V |           | V |      
       +---+           +---+      
     a   b   c   d   e   f   g    








Except for the Voidrider, all pieces in the game are borrowed from Chess. The game includes every piece from Chess except the Queen. All pieces have some additional powers beyond what they can do in Chess, the Pawns can't make double moves and can't capture by en passant, and castling works slightly differently.

Additional Powers

Every piece has the additional power of moving its space to an adjacent off-board location, but there are restrictions on this power. First, a space may be moved orthogonally but not diagonally. Second, it is illegal to move a space to any orthogonally isolated location, that is to any location where it will not share a side with another space. This restriction keeps all spaces within a manageable 7x9 playing area. Third, a Pawn may never move its space backwards.

When a piece moves its space, it moves along with it, for no piece may be left standing in the void, that is off a space.

The Voidrider

Like the other pieces, the Voidrider may move the space it resides on, but unlike the others, it can move its space further than the next adjacent location. A Voidrider may move its space as far as an orthogonal line of void extends from its space. But it is still subject to the limitation of placing its space at a location orthogonally adjacent to another space. This restriction is required on all pieces to keep the spaces within a manageable 7x9 playing area.

When a Voidrider moves across the board, it steps one space in any direction, but unlike other pieces, it is not blocked by void. When a radial line of non-space is all that separates a Voidrider from another space, it may ride across the void to the other space. Although the Voidrider can ride across void, it can never land in it. It will always move to another space or bring its space with it.


Since the King is the same distance from each Rook, left- and right-side castling are symmetrical with each other. The King moves two spaces toward the Rook, and the Rook moves to the space the King passed over. All usual castling restrictions apply, and there is the additional restriction that all the spaces between the King and the Rook must actually be there. If there is any gap of non-space between a King and Rook, they cannot castle.


The only differences between Voidrider Chess and regular Chess concern the setup and the pieces. These differences are all described above, and aside from these differences, Voidrider Chess follows the rules of regular Chess.


Playing Tips

Computer Play

If you have version 2.0 of Zillions of Games installed on your computer, you can play this game. Download file:

You can also play this game by email, using the web-based Play by Mail system on this site.


To play this game, setup a 7x9 board and place individual tiles on the initially unused spaces. When a piece moves its space, pick up the tile from the space it moves to, then place it on the space it moved from. Use regular Chess pieces for every piece but the Voidrider. Depending on your equipment, you can use two Queens, two Champions, two Archbishops, or two of something else for the Voidriders.

Sample Game

Here is a game I played against Zillions of Games. I later learned that it was playing at a moderate strength level. You can read the moves and comments in the box below, or you can click the "View" button to view the game with the on-line PBM system. You do not need Zillions of Games to view this game. All you need is your browser.


Mail Fergus Duniho at @

Written by Fergus Duniho.
WWW page created: December 31, 2002.