Oust can be played on a Go board or on several internet game sites. It is an abstract game for two players. One player uses the black stones and the other player the white stones. The size of the board may be selectable when played online. Draws and ties cannot occur in Oust. Mark Steere designed Oust in July, 2007.

Stone Placement

You initiate your turn by placing a single stone at an unoccupied point. Placing at least one stone is mandatory if possible. Otherwise, you must pass your turn. There will always be a move available to at least one of the two players.


A “group” consists of like-colored stones that are connected. A “connection” is formed between two stones that are adjacent horizontally or vertically.

Non-Capturing Placements

When you make a placement that does not form any connection with your own stones, you have made a non-capturing placement. A non-capturing placement ends your turn.

Capturing Placements

Placing a stone such that it connects to any of your other stones is only allowed in a capturing placement. Placing a stone that connects to one of you own may form a group of two, enlarge an existing group, or connect nearby groups. This is only allowed if the resulting group connects to at least one opponent’s stone. When the number of stones in your group is larger than all connected opponent’s groups you remove all connected opponent’s groups from the board. When the number of stones in your group is equal to or smaller than any connected opponent’s group, you must remove your own group. A capturing placement does not end your turn.

Sacrifice Placements

Placing a single stone such that it is connected to an opponent’s stone is a non-capturing placement. Because it is not a capturing placement, it is not subject to immediate removal. Sometimes this is the only way to end your turn.

Multiplacement Turn

There may be several placements made in one turn. After a capturing placement, it is still your turn. You must continue to make placements until you make a non-capturing placement, at which time your turn is concluded.

Winning The Game

The winner is decided either by resignation of when one player captures all of his opponent’s stones.


Oust is a fascinating game. It is so new that you can't find any writings on strategy. As of 10/26/07 there are only 8 players who have finished games.

I have seen player comment that the first player to run out of safe moves loses. It isn't that simple. I am seeing players overcome significant deficits of safe moves with clever use of sacrifices.

It would be very good to have a smaller board option, especially for learning the game. This would reduce the number of moves required to complete the preliminary (setup) phase. Aaron has this on his list of things to do.

Hopefully the interest in this game will increase to the point where a ladder is feasible. If interested, you can find open challenges or place a challenge on the challenge board. You can find a list of all players who have played Oust by selecting Oust on the players page and sorting for ratings. Most of us on that list would be happy to play a game.

Les Hazlett

After playing several "first" games with others, it seems that the rules lack clarity with respect to what happens when a single stone is placed next to an opponent's group. I edited the original rules to share with others hoping to clear up that point. Those modified rules are attached below above (Edited by DiEvAl, 02 Jun 2015 16:06).

lhh61 Les Hazlett - 12/21/07

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License