`In the earliest [trick-taking card] games the king was highest and the ace (or one) was in its logical position next to the two -- promotion above the king came later'.
-- John McLeod, `Card Games: Whist Group'

`Check! check! and two good pawns!'
-- Punch line of old anecdote about card players trying to sound as though they were playing chess

Cardmate

The idea of a board game with pieces and rules inspired by card games is one that I have nurtured for no less than fifteen years, but it was only in the last few months that I started filling in the details, with the help of Zillions of Games. The game described here is not chronologically my first endeavour in this field, but -- thanks to the 100-Square Contest, to which it is a submission -- it shall be the first one presented to the scrutiny of the Whole Wide World.

Rules

Cardmate is a Whist-influenced chess-like board game for two players, called Forehand and Rearhand. Forehand leads (moves first).

Equipment

The Board

The Cardmate board is a 10 by 10 square, with files labelled a to j and ranks labelled 0 to 9, so located that square a0 is at Forehand's left. There are two special two-square zones on the board: Forehand's palace in e0 and f0 and Rearhand's palace in e9 and f9.

It helps if the board is chequered and the two palaces and the line between ranks 4 and 5 are highlighted, though none of this is essential.

The Cards

The pieces that move on the board are called cards. The set or pack contains 56 of them, distinguished by rank (not to be confused with the other meaning of the word rank, a horizontal sequence of squares on the board) and by suit: there is a One (1), Two or Deuce (2), Three or Trey (3), Four (4), Five (5), Six (6), Seven (7), Eight (8), Nine (9), Ten (X), Jack or Knave (J), Queen (Q), King (K) and Ace (A) of Clubs (C), Diamonds (D), Hearts (H) and Spades (S). The ranks are ordered from lowest to highest; all suits are equal.

Each cards can in principle be dealt (that is, belong) to either player. The Shôgi approach (flat wedge-shaped tokens turned with their sharp ends towards the opponent) appears optimal for a physical set. (The other side can be blank or inscribed with the rank of the card only, for suit-shuffling purposes.) Or the cards could have the shape and size of dominoes, with rank and suit indicated on the two sides on backgrounds of two different colours.

Clubs and Spades should be inscribed in black (or other dark colours), Diamonds and Hearts in (shades of) red.

Setup

At the beginning the four Aces are taken out of the pack and set aside; each player then receives a hand consisting of half of the remaining 52 cards.

Chess variants typically abhor randomness, but there is hardly a card game that does not involve it (in the form of shuffling and dealing), though in the best among them (such as Bridge) care is taken that the game remain one of skill rather than luck. Cardmate tries to be both, so it allows the players to let chance play a lesser or greater part as they choose. There is a predefined setup, which is as follows:

  (Rearhand)
9   XD 8C 9S QC KS KD QS 9D 8S XH
8   7H -- 6C JH 5C 5S JC 6H == 7D
7   4D 2C 3H 1S -- == 4S 3D 2H 1C
          (four empty rows)
2   1D 2S 3C 4H == -- 1H 3S 2D 4C
1   7C == 6S JD 5H 5D JS 6D -- 7S
0   XS 8H 9C QH KC KH QD 9H 8D XC
  (Forehand)

Several notable properties:

Each player has two Kings.
And two cards of each of the other ranks (rank content).
And there are specific places where the cards of each rank sit (rank setup: Kings in the palaces, Queens next to them, Tens in the corners, lowest-rank cards in front, etc.). The arrangement is centrally symmetric, and all Ones are on different files.
Each player has two seven-card suits and two six-card suits, with high and low cards in each (suit content).
And the setup is such that Forehand's Clubs/Diamonds//Hearts/Spades correspond to Rearhand's Diamonds/Clubs//Spades/Hearts (suit setup).

These rules can be relaxed at will. The players may agree to leave to chance

the suit setup (as Forehand you start with the two red Ones on a2 and g2, the two black Sevens on a1 and j1, etc., but any card can be on either of the squares allocated for its rank),
the suit content (you have Ones on a2 and g2, Sevens on a1 and j1, etc., but they can belong to any suits. Thus the distribution of the suits in one player's hand may be, shall we say, 11-5-5-5 and in the other's 2-8-8-8, but how such a thing affects their chances is no easy question. This is implemented as a variant in the Zillions of Games rules file),
the rank setup (you get the same cards as in the predefined setup, but arranged in a random way on the three ranks closest to you),
the rank content (you get two Kings and any other 24 cards).

Moves

The ways in which a card moves and captures are determined by its rank only, not by its suit.

The cards ranking from One to Seven only move to, and capture on, orthogonally or diagonally adjacent squares. They have no initial double move. (Neither have the pawns in most chess-like games, whether they are as weak as the Fuhei in Shôgi, which controls one square, or as strong as the Panthan in Jetan, which controls seven.)
The One	moves and captures		straight forwards	and moves, but does not capture, straight backwards.
As a One it is confined to its native file; having caterpillared its way onto the opponent's half of the board, however, it butterflies into an Ace of the same suit, on whose considerably greater mobility anon. (This is essentially what is described in the first epigraph, only the word promotion has a slightly different meaning. Ontogeny recapitulates phylogeny.) Promotion is optional; there are situations in which it makes sense for a One to cross the middle of the board without promoting. A One that has declined promotion to Acehood on entering the opponent's half of the board does not promote when moving within it or on retreating from it; it can, however, promote upon reentry.
The Deuce	moves and captures	diagonally forwards		and moves, but does not capture, straight backwards.
The Trey		diagonally forwards	or straight forwards
The Four		diagonally forwards or sideways
The Five		diagonally forwards, sideways	or straight forwards
The Six		diagonally forwards, sideways or diagonally backwards
The Seven		diagonally forwards, sideways, diagonally backwards	or straight forwards
Here is a coloured ASCII diagram to show how these seven work, assuming that forwards is upwards (red copyright sign: can move and capture, green vertical bar: can move but not capture):			-©- ©-© ©©© ©-© ©©© ©-© ©©© -1- -2- -3- ©4© ©5© ©6© ©7© -\|- -\|- -\|- -\|- -\|- ©\|© ©\|©
The Eight	moves and captures	as the Knight in Chess		and moves, but does not capture, one square straight backwards.
The Nine		as the Bishop in Chess, -- any distance (up to 9 squares, given the size of the board) on the diagonals
The right of quiet retreat implies that Deuces and Nines are not colourbound, unlike their close kin in other games.
The cards from Ten to Ace (also called honours) capture exactly as they move, and move in the same way forwards and backwards.
The Ten	moves and captures	as the Rook in Chess, in the shape of the Chinese character shi2 `10'.
(Originally that shape stood for `all cardinal directions and the centre', that is, `everywhere'; it was associated with the number 10 because that number symbolised completeness and perfection. The Rook is the only piece whose move has remained the same in the entire history of Chess, and is the same everywhere, from the Maghreb through India to Japan; it is also the only piece that controls the same number of squares from everywhere on the board.)
The Jack	moves and captures	as a Knight, or as a Queen to one or two squares. He is a little less mobile than the Centurion in Francesco Piacenza's ArchChess or the Lioness in Adrian King's Scirocco, since he can only get to the squares a Dabbâba's or an Alfîl's move away if the intervening square is vacant.
(The Jack ranks below the Queen in Whist and most other card games, but in some games Jacks have an exceptional status -- in Skat, for example, they are the highest trumps. In recognition of this I gave my Jack a move that is similar to the Ace's whilst being weaker than the Queen's.)
The Queen	moves and captures	as her namesake in Chess.
The King		as his namesake in Chess. There is no castling.
The Ace		as an Amazon, that is, as a Knight or a Queen.

Captures

Capturing is by displacement, and the following rules apply:

A lower-ranking card can never capture a higher-ranking card of the same suit. (This means that an unpromoted One can't capture any same-suit card, and that no card can capture a same-suit Ace.)
Any card, regardless of rank, may (but never has to) capture any card of a different suit (which is then considered discarded).
A higher-ranking card must capture a lower-ranking card of the same suit (following suit has precedence over both different-suit capture and a quiet move). If more than one such capture is possible, the player may choose freely.

It doesn't matter what the suits of the two cards are, only whether they are the same or not.

Victory

You win a game of Cardmate if one of the following things happens:

You capture both of your opponent's Kings. (With the help of a well thought-out combination, it may be possible to do this already in the middlegame.)
A King of yours enters your opponent's palace. (This implies that the game isn't necessarily drawn even if both opponents have been reduced to a single King.)
You force your opponent to repeat an already-seen position.

This last rule is optional. I introduced it at a time during the playtesting when it seemed to me that Zillions of Games was inclined to repetition-draw games against itself way too often. Human players probably won't need it.

Strategy and Tactics

As literally as metaphors go, the tactics of Cardmate is coloured by the presence of suits: by far the most important device seems to be using one or more of your low-rank cards to draw an enemy high-rank suitmate to where it can be captured, or into engaging in a series of forced captures and enabling you to undertake any sort of hostile action against the opponent without interference (an undeclinable sacrifice). This also affects the strategy: the long-ranging cards (Nines, Tens and Queens), as well as the shorter-ranging but wide-scoping Jacks, should keep a low profile until the lower orders have been tangibly reduced in numbers and there is sufficient room for roaming without constantly running the risk of getting drawn. Drawing the opponent's Kings is harder (you have to get next to them), but eminently worthwhile.

As in all games where a player has more than one royal piece, the question of whether you can afford to exchange one of your Kings for material or positional advantage can be very interesting. When a King has been captured, the situation of the other one becomes more chess-like, though still with some peculiarities: for example, he can safely move to a square attacked by an enemy card of a different suit in a position where the opponent can make a same-suit capture somewhere else. And endgames of the type `King+Card vs King' are of two radically different kinds, depending on whether the non-royal card is of a suit different from the enemy King (and then it must capture him in the usual way, with help from its own King) or of the same one (and then it is used to draw him onto a square next to his rival, who dispatches him).

Games usually last around 80 moves, give or take 40 or so.

Notation

Chess notation is perfectly adequate (the short form always suffices, as every card type is unique). I favour using a colon for capture, a plus sign for the capture of a player's first King, a times signs for the capture of a player's second King and a sharp sign for the conquest of his palace.

Two Sample Games

... chosen for their brevity.

Forehand: Zillions of Games. Rearhand: Zillions of Games. Predefined setup.
1. 4Ci3 4Db6 2. 8Dj2 8Ca7 3. 8Dh3 8Cc6 4. 7Cb1 7Di8. Note that so far Rearhand replicated Forehand's moves. 5. 3Cd3 3Di6 6. 8Hc2 4Dc5 7. JSf3 9Sa7 8. 9H:c5 9S:c5 9. 2Sa3 9S:a3 10. 1D:a3 8Sh7 11. 3Cd4 8C:d4 12. 8H:d4 8Sg5 13. JS:g5 3Hc6 14. JS:g7 6H:g7 15. 8H:c6 JH:c6 16. 1Da4 QSh8 17. 8Di5 QS:h2 18. 8D:j7?? 7Dh8! The Eight is an unlikely card to get itself drawn into a sequence of forced captures, but this is exactly what has happened here. The continuation should have been 18. 7Si1 QS:i1 19. XC:j7 XH:j7 20. 6D:i1 or 19. ... QS~ 20. XC:j9, in either case leaving Forehand with very good chances. 19. 8D:h8 QS:f0+ 20. 8D:i6 QS:e0×.

Forehand: Zillions of Games. Rearhand: Zillions of Games. Predefined setup.
1. 4Ci3 4Db6 2. 3Sg3 8Ca7 3. 8Dh2 8Cc6 4. 7Cb1 7Di8 5. 3Cc3 4Sf6 6. 8Hc2 4Dc5 7. 4He3. The Treys, Fours, Sevens and Eights are ZoG's favourite cards in the opening. 7. ... 9Sa7 8. 8Df3 4Se5 9. 3Sf4 4S:f4 10. 4H:f4 7Hb8 11. 3Cd4 8C:d4 12. 8D:d4 4Dc6 13. 8D:c6 2C:c6 14. 6Sd2 3Hb6 15. JSe3 5Cf7 16. JDf3 1Sd6 17. 9Ce2 1Sd5 18. JS:d5 2C:d5 19. 9H:b6 JH:b6 20. QDg1 KSe8 21. 7Si1 2Ce4 22. XC:j7 2C:f3 23. 9C:f3 8S:j7. This was Rearhand's last freely chosen move in this game. 24. 8Hd4 JH:d4 25. 6Se3 JH:f4 26. QH:d9 JH:g2 27. 5D:g2. An unnecessary act of hostility, strictly speaking -- 27. QH:e8+ 9S:e3 28. QH:f9× would have been more efficient, but Forehand is not in a hurry. 27. ... 9S:e3 28. QD:e3 XD:a2 29. QD:e8+ KD:e8 30. QH:e8×.

The Implementation for Zillions of Games

I made the bitmaps for the cards for another game, played on a very different board. When I then came up with Cardmate, which was to be played on a 10 by 10 square board, I found that the size and the colours of the Scirocco board were perfect for my purposes, so I decided I'd use that with a couple of minor modifications. Since ZoG can't flip pieces, there was no point in making the cards pointed, so they have the usual shape of playing cards; ownership is identified by coloured stripes, pale bluish cyan for Forehand and brown for Rearhand. The Cardmate board is flippable, however.

Two variants are included. One, `Predefined setup', starts the game from the initial position shown above. The other, `Random setup', performs suit-shuffling: it preserves the rank content and setup of both hands, but the suit content and setup are determined by chance. The game starts with the four kings on an otherwise empty board; click on the green light to have the rest of the pack dealt.

Created by Ivan A Derzhanski.
Last modified: 18 June 2000.