Jetan

Description

Jetan is a board game, also known as Martian Chess because of its similarity with chess, similarity coming from being played in a 10x10 black and orange checkered board. The game was invented in 1922 by Edgar Rice Burroughs an introduced in his novel The Chessmen of Mars. Rules of the game appear to be a bit confusing because Burroughs' rules in the text are different from the rules recollected by himself in the apendix.

The game is presumed to represent an ancient battle between the Black race of the south and the Yellow race of the north. On Mars the board is usually arranged so that the Black pieces are played from the south and the Orange from the north.

The pieces

Jetan pieces (and their capabilities) are the following:

Panthan

eight per side, represented with 1 feather. They move 1 space, forward, side, or diagonal, but not backward.

Warrior

two per side, represented with 2 feathers. They move 2 spaces straight in any direction or combination.

Padwar

two per side, also represented with 2 feathers. They move 2 spaces diagonal in any direction or combination.

Thoat

two per side, represented as a mounted warrior with 2 feathers. They move 2 spaces, one straight and one diagonal in any direction.

Dwar

two per side, represented with 3 feathers. They move 3 spaces straight in any direction or combination.

Flier

two per side, represented with 3 bladed propellor. They move 3 spaces diagonal in any direction or combination, jumping over intervening pieces if necesary.

Chief

one per side, represented as a diadem with ten jewels. He moves 3 spaces in any direction, orthogonal, diagonal or combination.

Princess

one per side, represented with a diadem with one jewel. She moves same as Chief, but also jumping over intervening pieces. The Princess may not move onto a threatened square, and can't take an opposing piece. She is allowed to one ten-square movement at any time during the game, known as The Escape.

The board

Pieces are placed in two rows at the sides of the board. The order in the first row, from left to right of each player is Warrior, Padwar, Dwar, Flier, Chief, Princess, Flier, Dwar, Padwar, Warrior, and in the second row is Thoat, the eight Panthans, Thoat, as you can see in the following ascii picture:

+---+---+---+---+---+---+---+---+---+---+
| W | P | D | F | C | P | F | D | P | W |
+---+---+---+---+---+---+---+---+---+---+
| T | p | p | p | p | p | p | p | p | T |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
|   |   |   |   |   |   |   |   |   |   |
+---+---+---+---+---+---+---+---+---+---+
| T | p | p | p | p | p | p | p | p | T |
+---+---+---+---+---+---+---+---+---+---+
| W | P | D | F | C | P | F | D | P | W |
+---+---+---+---+---+---+---+---+---+---+

The rules

Victory

The game is won when any piece takes opponent's Princess, or when a Chief takes a Chief.

Drawn

The game is drawn when Chief is taken by a piece other than the opposing Chief, or also when both sides are reduced to three pieces or less (of equal value) and the game is not won in the next ten movements.

Movement

Moves are done one piece at a time, alternating both sides. The side to perform the first movement is choosen in a random way, previously accorded by both sides.

Two pieces can not live in the same square except in the final move of a game where the Princess is taken. When a player, moving properly and in order, places one of his pieces upon a square occupied by an opponent piece, the opponent piece is considered to have been killed in battle and is removed from the board.

The combined moves explained for pieces are valid in a complete way, without visiting the same square twice in a single move.

More

Gambling

Martians usually gamble in Jetan. They put price on the pieces, so when a piece is taken the player must pay the taker the accorded amount.

Copyright

Rules for the game Jetan are Copyright © 1922 by Edgar Rice Burroughs. This is a free interpretation of the game without permission of the author.

Jetan has often been accused of unclear rules, but a careful analysis of The Chessmen of Mars shows that there are in reality very few truly unclear rules. See especially Chessmen of Mars Chapter 2, Chessmen of Mars Chapter 17 and Chessmen of Mars Chapter 22 (appendix at the end). Further clues can be found in the original pulp publication of the text.

Pieces always move their exact count of steps, not less.

Panthans can never move backwards, not even diagonally backwards.

Panthans cannot promote, and it is usually not a problem since they tend to get stuck in midfield.

Thoats do not move like chess knights, since they can also turn back to the square next to the one where they started their moves.

Warriors always move orthogonally, never diagonally.

The princess can always move through a threatened square, although she is not allowed to stop her move on one.

The chief can move any combination of orthogonal and diagonal moves, up to its three square limit.

The only serious remaining lack of clarity is whether the thoat can jump or not. Most interpretations follow Edgar Rice Burroughs's appendix where the that is not a leaper.