Rosette is an almost literal transposition of Go to the triple contacts of a honeycomb grid. All the usual Go rules apply.

Rosette positionRules
The board starts out empty. Both players, Black and White, have enough stones in their colour.

Placement
Players take turns, placing one of their stones on a vacant point at each turn. Black moves first. Moving is not compulsory: a player may pass his turn without losing the right to move on his next turn. The game ends if both players pass on successive turns.

Once played, stones are not moved, but they may be captured. A group is a stone along with all other stones one could reach from it through a series of single steps between like coloured stones. A group lives

  • so long as at least one of its stones borders on one or more vacant points, called liberties, or ...
  • if it contains a rosette, six like coloured stones around a small hexagon.

If a group without a rosette loses its last liberty it is captured and removed from the board.

Suicide
Placing a stone where it has no liberties is illegal. However, if a stone makes a capture it inherently gets a liberty by the removal of the captured stones. In such cases placement at a point with no liberties is legal.

Ko
A move may not result in a position that did occur before with the same player to move.

Seki
'Seki' may occur: groups may keep each other in a mutual stranglehold in which neither player can attack without losing a group. Vacant points inside a seki do not count.

Object
Ultimately the object of the game is to conquer more territory than the opponent, so obviously after a game has ended, there's counting involved. There are two systems for counting: Japanese and Chinese. The difference may be one point.

Counting
  • The Japanese count the vacant points surrounded by a player plus the stones has captured. As a shortcut, these captured stones are placed inside the opponents territory, to reduce it with a corresponding number of points.
  • The Chinese count both a player's stones and the vacant points of territory surrounded by him. Captured stones do not matter since placing them inside the opponent's territory doesn't alter the score.

Komi
Black has an advantage the point value of which is not known and can only be guessed. We'd say that 4,5 or 5,5 is probably not too far off.