Fig. 1: Initial position on the home squares.
Chain Reaction by Sid Sackson Game manual ABACUSSPIELE 1993 Translation by Ron Hale-Evans, with a lot of help from online translation software. Edited and clarified by Marty Hale-Evans. Many thanks also to Hanno Girke and Chad McDaniel. Please send corrections to Ron Hale-Evans <rwhe@ludism.org>.
A gripping strategy game for 2 players, by Sid Sackson
1 game board of cloth 11 light game pieces of wood 11 dark game pieces 2 scoring markers 1 die 1 rule booklet
The players take alternate turns of up to five segments, trying to move game pieces from their home squares over the opposing goal line, in order to score points. After the first segment of a turn, only towers made of two game pieces may be moved. Each tower is broken down during its move, and one of its pieces may be used to build a new tower on another square. Intelligent use of this move technique can lead to "nuclear chain reactions", in which up to five towers are involved. There must never be more than one tower on the board at one time. Any tower on the board must be moved during the following turn segment by the player whose piece is on top. The game ends with the achievement of an agreed-upon number of points.
Each player receives 11 game pieces of a single color and a scoring marker. Game pieces are placed on the players' home squares as shown in Fig. 1. There is a scoring track around the outside of the board. The scoring markers are placed on the scoring square bearing the number "0". The players agree on a victory score of at least 12 and at most 24 points. The younger player takes the first turn, and the other player assumes control of the die.
Players use the die to keep track of available turn segments left in the turn. The number on top of the die indicates the maximum number of turn segments still available. The die should be managed by your opponent during your turn.
Each turn consists of up to 5 turn segments.
During the first turn segment, an individual game piece may be moved exactly 1 square in any direction. It may be set on a piece of its own color or of the opposing color, in order to form a tower. After the first turn segment of your turn, you may only move a tower.
A tower always consists of exactly two pieces of the same or different colors. The color of the piece on top determines who controls the tower. Only the player controlling a tower may move it, and any tower on the board must be moved during the following turn segment by the player controlling it.
If a player moves a game piece during his first turn segment without forming a tower, he may take no further turn segments during the current turn. The turn passes to his opponent.
However, if there is a tower on the board at the beginning of your turn (with your own color piece on top, of course), then you must move this tower. You may not move an individual game piece.
If there is no tower on the board at the beginning of your turn, and you wish to take more than one turn segment, then you must form a tower on your first turn segment.
You may take the second through fifth turn segments only if you control a tower on the board. The tower is broken down, and both game pieces are moved in the same direction. The lower piece of the tower is set on the first square in the direction moved, and the upper game piece is set on the second square in that direction.
(Fig. 2 shows an example of a position, and in Fig. 3 one can see a move to the right.)
If there is already a game piece on one of the two squares, then the piece you are adding to that square is placed on top and a new tower is created.
Note! There may never be more than one tower on the board at one time! A turn segment during which two towers are built is illegal (see Fig. 4).
If a player builds a tower with a piece of his color on top during his turn segment, then he may take another turn segment. By skillful use of this movement technique, a player may take up to five turn segments.
There are four ways a player can end his turn.
Generally speaking: If a player ends his turn, then a tower topped with a piece of his own color may not remain anywhere on the board! A tower with an opponent's piece on top may remain, but the opponent must take his first turn segment with this tower.
Any tower on the board must be moved during the next turn segment!
Four movement examples are shown, all based on Fig. 2.
Fig. 3 shows a legal move to the right. Since no new tower is built, it is Black's move next.
Fig. 4 shows a move diagonally up and to the left. This move is illegal, since two towers are built.
Fig. 5 shows a legal upward move. The lower piece is set on the first square. The upper piece is set on the second square. A new tower is built on the first square with a black piece on top. Now it is Black's move, and he must take his first turn segment with this new tower.
Fig. 6 shows an optimal move. A new white tower is created, and White may take another turn segment.
If a player succeeds in moving the top piece of a tower over the seven-square-wide goal line of his opponent, then he receives 1 point.
If he moves the top piece of a tower onto the middle square behind the opposing goal line, then he receives 2 points, as indicated on the game board.
The scoring player's scoring marker is then moved forward on the scoring track by one or two points, as appropriate.
When a game piece leaves the board during a turn in which a player scores, replace it onto a home square of the scoring player immediately. First, place pieces in the middle row "A" (see Fig. 1). If this row is completely occupied, place pieces in either row "B" or row "C". If all home squares are occupied, place pieces onto any free square of the scoring player's half of the game board.
Important: Replacing a game piece is not considered a turn segment.
If a player cannot take a legal turn, then his scoring marker is moved back two squares. Any tower on the board is broken down, and the freed piece is placed onto a home square. [Presumably, the "freed piece" is the piece that was on the bottom of the tower. --Trans.]
If a player achieves the agreed-upon number of victory points, then he wins the game. However, he must have a lead of at least 2 points. If he does not have this lead when he reaches the victory score, then the players may either agree on a draw, or continue the game until one of them wins with a 2-point lead.
Both players may agree upon an additional victory condition: if a player succeeds in occupying all 7 squares in front of the opposing goal line, without his opponent being able to destroy this position on his next turn, then he wins the game immediately.
Last updated 2002-08-11.