Chess Variant I

by zenquaker

I had been trying to think of what my next big project was going to be. That is, what am I going to do with myself this year? That was when I was looking at Adjutant as a dead project. One of the ideas I had was to do a blog where I presented a new Chess variant every week for a year. Often when others present Chess variants in online forums I am very critical of them. But I don’t like people who never do anything but criticize and complain, and I don’t want to be one of those people. So I thought having a blog presenting my variants would be a more positive contribution to the Chess variant community.

I have decided to go forward with Adjutant. Even if there is not much interest, it could serve the Chess variant community in ways the community is not being served currently. That is, it’s not pointless. It may have a very small point, but it’s got one. That means that I’m not going to have time to do a full presentation of a new Chess variant every week. This blog still gives me an opportunity to present a limited presentation of a Chess variant every now and then. Before doing that, I thought it would be good to present some of my general thoughts on Chess variants.

My general thoughts stem from a wiki I read once that tried to define what a Chess variant is. The conclusion of the owner of the wiki (despite some of the people in the conversation disagreeing) was that a Chess variant was a game where victory was determined by the status of a particular piece. In Chess, the particular piece is the king, and it’s status as being checkmated or stalemated determines who the winner is (if anyone). The problem with this is Take-All Chess. In Take-All Chess, the king is a normal piece, and the goal is just to take all of your opponent’s pieces. Under the definition given in the wiki, it’s not a variant of Chess, despite the fact that it uses the same board, the same pieces, the same movement, and the same captures. To me, a Chess variant is a game derived from Chess or one of the cousins of Chess. I say the cousins of Chess because Chess was derived from another game. In fact, there are a whole host of games around the world that can trace their origins back to the ancient Indian game of Chaturanga.

That made me think of the work I did on Poker variants. I was dissatisfied with the standard way of categorizing Poker variants, mainly because it because unwieldy when dealing with over 1,000 variants. What I came up with (although I did not implement it) was a classification based on while rule(s) of basic Poker were broken by the variant. If we are to apply this to Chess, we must first determine what the rules (or features) of Chess are that can be violated. Given that my definition of Chess variant includes the cousins of Chess the features should include those common to the cousins of Chess. The cousins of Chess I think of as the “national” Chess-like games: Chaturanga (Indian Chess), Makruk (Thai Chess), Shatranj (Persian Chess), Shogi (Japanese Chess), Sittuyin (Burmese Chess), and Xiang-Qi (Chinese Chess). So what are the common features of these games?

  • Royalty: One piece’s status determines victory. Variants can be categorized by how many different types of pieces determine victory, and how many total pieces there are which determine victory.
  • Death Match: Capture of the piece determines victory. Variants can be categorized by different ways victory is determined.
  • Differentiation: There are different types of pieces that move differently. Six to ten different types is the range for national Chess-like games. Five or less would be considered low differentiation, eleven or more would be considered high differentiation.
  • Static Pieces: The same pieces are used every game. A popular variant where this is not true is Chess with Different Armies.
  • Displacement: Pieces are captured by landing on the square they occupy. Variants can be categorized by how pieces capture. For example, Rifle Chess and Benedict Chess use capture by attacking the square a piece occupies.
  • Promotion: A subset of the non-royal pieces can promote and change their movement. Usually only the weakest pieces (pawns) can promote, but in Shogi most of the pieces can promote.
  • Rectangular Grid Board: The board is a single rectangular set of square cells. Some times the piece move on the vertexes of the cells rather than the centers, but the two methods are functionally equivalent. Variants can include different cells (such as Glinski’s Hexagonal Chess), different shaped arrangements of square cells (such as Omega Chess or Fortress Chess), or multiple boards (such as Alice Chess or Bughouse).
  • Board Size: The range of the number of cells on a board for national Chess-like games is 64 to 90 squares. Less than that could be considered small and more than than could be considered large. I would further classify it using the difference of 26 cells seen in the national games as an interval. Then 37 to 63 would be small, 10 to 36 would be tiny, and nine or less would be miniature. On the other side 91 to 107 would be large, and 108 to 134 would be huge, and more than 135 would be gargantuan.
  • Static Board: The board does not change during play. This one is rarely broken, since it is hard to make changeable boards. Beyond Chess comes with 64 black and white tiles you can use to make shifting boards.
  • No Hidden Information: Once the game starts, you know everything there is to know about it. There are two common ways this feature is broken. One is fog of war, where you don’t know where some or all of your opponent’s pieces are. Kriegspiel is probably the best known of such variants. The other is randomness, where dice or cards are introduced into the game.

There are also some secondary features that can be used. These are features which distinguish Chess from the other national Chess-like games:

  • Static Setup: The pieces always start the game in the same positions. Sittuyin is the only national game that breaks this rule, but Chess960 is a popular variant that does as well.
  • Capture Kills: Captured pieces are removed from the game. Shogi breaks this rule by having captured pieces switch sides.
  • Two Player: I put this one here because I think the modern version of Indian Chess (Chaturanji) is a four player game. If I’m wrong about that two players would just be a primary feature.

The idea here is not to try and fit each game into one category, but to rather look at the features of the games. Then you can look at the features for each game, and look at games that share one or more features.