|9tka ("dziewiątka" = "nine" in Polish) is a 2-4 players abstract board game invented by Adam Kałuża in 2007.
9tka is played on a 11x11 board. The inner 9x9 region is divided to nine 3x3 sections:
The goal of the 9tka is to conquer more 3x3 sections than other players. A section is conquered by a player if he has more stones of his color in that section than other players (in the case of a tie, the section is not conquered by anyone).
If two or more players have conquered the same amount of sections then the winner is the one who started the game last among them.
Below is an example of a finished game:
Blue player has conquered one section (top middle)
The game consists of three phases.
During the first phase players take turns, placing exactly one black stone (neutral) in each of the nine sections. These stones cannot be placed on the outer cells of the inner 9x9 region of the board (i.e. on the 2nd and 10th rows, "B" and "J" columns). Below is an example of the position after the first phase is completed:
During the second phase players take turns placing one of their stones per turn on the edge squares of the board (except for the corners). This phase ends when all 36 (9 stones per edge x 4 sides) edge squares are occupied with stones. Below is an example of the position after the second phase is completed (in a game with 3 players):
The third phase is about conquering the 3x3 sections. During this phase players take turns sliding their stones from the edge of the board along a straight orthogonal line of empty squares towards the inner region of the board until they hit another stone (the stone cannot stop just at any square, they slide all the way until they hit another stone). Once the stone stops in the inner region of the board, it stays there until the end of the game (i.e. it cannot move anymore).
During the game some stones may become blocked if the square next to them (in the sliding direction) becomes occupied with another stone.
If a player cannot move any of his stones then he passes his turn. The game ends when all players run out of moves.