Goal: The object of DNA is to possess the greatest value of pieces at the end of the game.
Materials: DNA requires a chess board (or any 8x8 square grid), a set of Icehouse pieces, and enough space to keep pieces off the board in two separate locations for each player: the gene pool and the archive. Each player gets one color and starts all of the pieces in the gene pool. DNA is designed for four players (see variations, below).
Starting the game: A single small piece of each color is placed in one of the center four squares of the board. Which color goes in which square does not matter. Some method should then be used to determine which player goes first. It will be important at the end of the game to remember the starting player.
Turn Sequence: There are three elements to a turn: placement, scoring, and mutation. Placement must happen first. The player then has the choice of mutating and then scoring, or vice-versa. After a player has placed, mutated, and scored, the turn moves to the next player.
Placement: A player may take any one piece from either his/her gene pool or archive and place it on any location on the board. Only one piece may be placed per turn. Pieces may not be moved once they are placed (although they can be exchanged for other pieces - see mutation).
Mutation: Mutation transforms one or more pieces adjacent to the piece that the player has just placed. Mutation does not transform the placed piece itself. If there are no pieces adjacent to the placed piece, no mutation can occur. The largest pieces possess three points of mutation value, mediums two, and smalls one. A player must use as much mutation value as possible when mutating adjacent pieces. Mutation can be used to either change the color or the size of an adjacent piece. The cost to change the size of a piece is one point per size increment. Changing a small piece to a medium would therefore cost one point, and shrinking a large to a small would cost two points. The cost to change the color of a piece is dependent on its size. Smalls cost one, mediums two, and larges three.
Example: Bill places a large piece. It is adjacent to other pieces, so he must use as much mutation as he can (three point's worth, in this case). He changes an adjacent medium piece from red to green (two point cost) and then shrinks an adjacent large to a medium (one point cost). He has used all his mutation points and is done. If he has not scored yet, he now must do so (assuming he has scored at all).
Mutation cannot be used to make a small piece disappear. It is illegal to change the color of a target piece twice or to increase and then decrease (or vice versa) the size of a target piece. Mutation will require players to swap pieces on the board with those in the gene pools. Pieces in archives are off limits. If a player wants to make a certain mutation, but the piece they want to use is not available, tough.
Scoring: The basic unit of scoring is a strand. A strand is any three pieces in a row - horizontal, vertical, or diagonal - that the player forms when placing a piece, as long as that piece is on one of the endpoints of the strand. One strand is worth one point. A player can score multiple points by forming multiple strands. A player also scores bonus points if a newly formed strand contains: three different colors, all the same color, three different sizes in succession (small on one end, medium in the middle, and large on the other end), or three pieces of the same size. A player scores one point for each condition satisfied per strand.
Example: Bill places a small green piece, and forms two strands. He scores two points - one for each strand. One strand is composed of two other small green pieces. He scores two bonus points - one for three pieces of the same color and one for three pieces of the same size. The other strand is composed of a medium yellow next to his and a large red on the opposite end. He again scores two bonus points - one for three different colors and one for a succession of sizes, in this case small to large. His total is six points.
Once a player has added up his/her score, he/she captures pieces from the other player. Pieces can be captured from any combination of players, in either their play or archive areas. A player must capture (if possible) as many points worth of pieces as he/she scored. When capturing from a gene pool, smalls cost one point, mediums two, and larges three. When capturing from an archive area, each piece is two points more expensive (smalls cost three points, mediums four, and larges five). There is no restriction on what pieces can be taken, as long as they add up to the total scored. Captured pieces are then placed in the capturing player's archive area.
Example: Bill has scored six points. He takes a small piece from a player's archive (three points cost) and a large piece from another player's archive (three points cost). He is now done. If he has not mutated, he now must do so.
The End of the Game: The game ends at the end of a turn in which no player has any pieces in a gene pool. Extra turns are played if the game does not end on the fourth player's turn to equalize the total number of turns per player. If gene pool pieces run out on the second player's turn, for example, the third and fourth players each get a final turn. The value of the pieces (small = 1, medium = 2, large = 3) is totaled for each player's archive. The player with the highest total wins.
Variations: DNA can be played by two or three players. The recommended three player variation is for the fourth color to remain inaccessible to players except in the starting placement on the board and through mutation. The flavor can be varied by having the fourth color either count or not count as pieces in a gene pool for determining the end of the game. Two players can either play like three players except with two inaccessible colors, or each player can start off with two colors. The starting setup is by no means meant to be set in stone. Feel free to experiment with different locations or even amounts for the initial pieces. Of course, try to keep the start position fair for each player.
Basic Strategy: Try to hold on to as many pieces as you can in
your gene pool. It is much better to place from your gene pool than your
archive. Mutate pieces of your color on the board to a different color so
that you get them back. If you don't need to mutate before you score, don't.
You can mutate after you score in order to deprive your oppenents of good
opportunities. Try not to allow your opponents plays in which they can score
with multiple strands. When you take your opponents' pieces for scoring,
try to deprive them of a certain size. Take all of an opponent's one point
pieces, for example.