IceGammon

Ron Hale-Evans (rwhe@apocalypse.org)

Beta version of 2001-01-19

IceGammon is the first published Icehouse Backgammon game. It was originally called Martian Backgammon (to parallel the Icehouse games Martian Chess, Martian Go, Martian Tic-Tac-Toe, etc.) until I discovered there was another in-progress Icehouse game with the same name, by long-time Icehouse player Eric Zuckerman. As of January 2001, he has been promising to ``really...publish the rules to Martian Backgammon very very soon'' for at least five months and maybe more than a year. Rather than fight it out for the name, I decided to call my game IceGammon and scoop Eric by publishing the first Icehouse game in this particular memetic ecological niche.

The following rules still need playtesting. If you have played IceGammon, please email me at rwhe@ludism.org and let me know what you liked or didn't. These rules also presuppose some familiarity with Backgammon. In particular, the doubling cube has not been described in detail, as its use in IceGammon is practically identical to its use in Backgammon.

Some illustrations would be nice, too...

Rules

1. IceGammon is a two-player game using an ordinary (Anglo-American) Backgammon board and Icehouse pieces.

2. There are two ways to win IceGammon. You can win by bearing all your pieces off the board, as in ordinary Backgammon, or you can win when your opponent cannot move, as detailed below.¹

3. The player to go first is chosen by any means acceptable to both players, such as rolling the dice.

4. Each player begins with a full stash of 15 Icehouse pieces of one colour. The pieces have the same point values as in Icehouse: 1 point for small pieces, 2 points for medium, and 3 points for large pieces. (Point values do not count in scoring the game, but only when players are moving pieces.)

5. All pieces start off the board and must be entered by throwing the dice.² Players can enter their pieces in any order. Players can move pieces already on the board before they have entered all their pieces.

6. The first player's pieces start at the northeast of the board and move counterclockwise, bearing off in the southeast quadrant. The second player's pieces start at the northwest of the board and move clockwise, bearing off in the southwest quadrant.³

7. Players take turns rolling three ordinary six-sided dice, then choosing two of them with which to move their pieces. This means that it is possible to roll many more doubles than in ordinary Backgammon.

8. As in ordinary backgammon, each die counts individually, so that when you throw a 3 and a 6, and the spaces 3 and 6 ahead of a piece are blocked, you can't move that piece 9 spaces ahead. In this case, if the spaces you are moving to are not blocked, you can move one piece 3 spaces and another piece 6, or move a single piece 9 spaces.

9. Doubles are played as follows. First move your pieces as if you threw the doubled number four times, as in ordinary Backgammon. Then move your pieces as if you threw the opposite number four times. (The opposite number is the number on the other side of the die, which is always 7 minus the number thrown. Thus, the opposite number of 6 is 1, the opposite of 5 is 2, and so on.) Finally, throw the dice again. This action can be repeated indefinitely if a player keeps throwing doubles.⁴

10. If your opponent has a piece or pieces resting on a space, only one of your pieces having the same point value or greater than the pieces on the space taken together can land on that space.⁵ When you land on an opponent's space, you must either capture or pin all the pieces on that space, as follows.

11. Capturing works as in ordinary Backgammon, sending the captured pieces to the bar. If you have pieces on the bar, you must re-enter those pieces before you do anything else.

12. Pinning prevents an enemy piece from moving. To pin an enemy piece, place your own piece on top of it. One piece can only pin another piece if the attacking piece has the same point value or higher as the defending one. Pinned pieces cannot move until the pinning piece moves.⁶

13. You can pin your own pieces, to prevent your opponent from doing so, but pieces always move individually; you cannot move a stack of pieces as if it were one piece.

14. Multiple pins are permissible. Only the top piece counts for determining whether a space can be landed on and whether a stack can be pinned. For example, Green pins Yellow's 2-pointer with a green 2-pointer, then Yellow lands on the space again and pins Green with another yellow 2-pointer. If Green lands on the space again with another 2-pointer, s/he can either free the green piece in the stack by capturing the top yellow piece or can pin the stack. However, Green cannot land on the space with a mere 1-point piece, because Yellow is now considered to have a single 2-point piece on that space.

15. You do not need to have all your pieces on your home board in order to bear any off. However, you must bear off all your 1-pointers before you can bear off any 2-pointers, and all 2-pointers before you can bear off any 3-pointers.

16. You do not need to make an exact throw to bear your pieces off the board. As long as your die roll is at least enough to move your piece off exactly, and you have borne off all your smaller pieces, you can bear a piece off.

17. Instead of bearing off a piece, you can re-enter it. Simply treat your outer board as if it were any other board and move your piece onto the appropriate space accordingly. However, once you have borne off a piece, you cannot re-enter it.⁷

18. A doubling cube can be used. Its use in IceGammon is identical to its use in ordinary Backgammon.

19. There are four kinds of win possible in IceGammon.
    • When you win a game in an ordinary way, it's called a Mon and is worth 1 point.

    • When you win a Mon before your opponent has borne off any pieces, it's called a Gammon, and is worth 2 points.

    • When you win a Gammon, and your opponent still has pieces on the bar, yet to be entered, or on their outer board, it's called an IceGammon, and is worth 3 points.

    • When you win an IceGammon, and all your opponent's pieces are on the bar, yet to be entered, or on their outer board, it's called a Mons Olympus, and is worth 4 points.

Footnotes

... below.¹

This rule is a more drastic version of the one found in Backgammon's ancestor Fayles.

... dice.²

This rule is similar to a number of Backgammon's predecessors, including Paumecary and Puff.

... quadrant.³

This rule is taken from Backgammon's predecessor game Buff de Baldriac, and makes for aggressive play, since both players' pieces are in contact throughout most of the game.

... doubles.⁴

This doubles rule is similar to the one in German/Russian Backgammon, and might seem to make doubles exceptionally powerful, except that as already mentioned, whenever you can't move a piece, you not only lose the rest of your turn, you lose the game.

... space.⁵

Since players can only move one piece at a time, the smallest point value guaranteed to block your opponent from landing on a space is 4 points.

... moves.⁶

The pinning rule is based on the one in the Backgammon variant called Plakato -- but with an Icehouse twist.

... it.⁷

This rule is taken from Pachisi.