[Game Setup] Parallel Fractional Go, Game 3

This Go variant is a lot of fun, and I would like to organise another game!

How to play

Base Setup

Players are grouped into two teams: Team Black and Team White. Each team will receive points for their Team Colour (see Objectve).

Parallel Moves

When all players have submitted a move, all stones are simultaneously placed on the board. If two or more players played the same move, a collision occurs (see Collision Handling).

Fractional Stones

Stones have multiple colours, and the chains of each colour are determined individually (note that chains can overlap with each other).
Players place stones with two colours, one of them being the players Team Colour, and the second colour is shared with a player from the other team.

Collision Handling

When two or more players submit the same move, a single stone is placed at that position, with all colours of the colliding players.

Capture Mechanic

Chains without liberties are removed as usual. When multiple chains simultaneously lose their last liberty, first all Old Chains are removed simultaneously, then all New Chains without liberties are removed.

  • New Chains are those including a stone placed this round.
  • Old Chains are those that don’t include a stone placed this round.

Note that removing Old Chains might free up liberties of New Chains, allowing them to avoid capture (like in normal go, a stone that captures a Ko).


Both teams receive points for their team colour only. All secondary colours are ignored for the scoring. The team with more points wins!

Where to play

Previously we played on the forum, but recently this variant is playable on https://www.govariants.com/ !

Currently it looks like this:

The transition each round is automated, and no arbiter is needed. We can use this thread for discussion and commentary (private discussion among teams is not allowed).

Related References

Simultaneous Fractional Go Game 1
Simultaneous Fractional Go Game 2
Go variant: SAS Go
Online Parallel Multiplayer Go Prototype
Fractional Multicolour Go
Diplomatic Go
Collective development of a server for variants


Count me in!


I’m in!


On OGS, after you click a stone onto an intersection, you can click on it again to remove the stone. On the variant server, you can only move your placed stone to a different intersection, but not remove it from the board, correct?


What is the game-end condition? ​ ​ ​ If it ends in the diagrammed position from
Simultaneous Fractional Go Game 2 (Setup) - #14 by Jon_Ko
, ​ will the K4 region be points for White?


I’m pretty sure that’s true, yes. Do you want it to change?

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Unless that’s too much to ask… :slight_smile: Also is it me, or are the stones kinda tiny?

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Currently the variant doesn’t have an endgame condition programmed yet (that’s a missing feature). We can just decide when we want the game to be over. I’d go with the rules of game 2 for that:

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Yes, here’s the detailed definition I propose:

If C is a colour, a maximal set of connected empty intersections is called C-territory if all adjacent stones feature colour C.

This may be a bit unintuitive, but team black is anyway likely to try to break into that territory.


If C is a team colour, a maximal set of connected empty intersections is a C-territory if no adjacent stone features another team colour.

We can use this if you prefer. I believe that either would play similar.


It’s not too much to ask, I just can’t promise we’ll change that in time for that game.
And yes, the stones do seem a bit tiny. That can be changed easily.


By the way, I’ve written the rules for 6 players, because this is currently the max., but I believe that we could also increase that without much work.

I don’t think 6 is the maximum. We can have 6 secondary colors (red, green, blue, cyan, magenta, yellow), so we can have 12 players (6 per team).


oh, my bad!

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I’ll join!


I’ll play.

Is it a similar rate of play/time controls as the last game?

The transition kicks in immediately once the last player has submitted their move?


Yes exactly

That was what I had in mind. The website will not timeout anybody, and my intention is to play about 1 move per day. We can post here for reminders.


I dont seem to be able to find the link to the game anymore?


Yes, the first game proceeded to the second round by accident (I assume moves were played to try out the user interface).
When we decide to start, I’ll create a new game and post the link here.


@fuseki3 has told me that they would like to play. With that we have six players, so lets start!

I’m thinking of determining the teams and playing order randomly. But if you prefer a specific constellation, please let me know.

Unlike the first two games, we need to fix the colours beforehand. I’d say that Black and White are fixed as team colours, but we can freely choose three secondary colours. The following colours are currently available (red, green, blue, magenta, cyan, yellow):


I don’t have a specific preference. Note that we are not necessarily limited to these.


Would love to be black/cyan ~

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