Rules
Japanese Rules (primary source)
Irensei is played on a 19x19 Go board, with Go stones, and Go capturing rules, and Go ko rules, but with one significant difference: the goal is not to surround territory, it is to get 7-in-a-row in the center 15x15 area (in other words, stones on the first and second line can’t be used as part of a 7-in-a-row). A winning 7-in-a-row can be either orthogonal or diagonal, but it must be a straight unbroken line of friendly stones
To lessen the turn order advantage, Black and White have subtly different winning conditions:
- Black must get exactly 7 stones in a row in order to win
— If Black makes 8-in-a-row or more anywhere on the board (even on the first and second lines), this is called overlining and Black loses the game immediately - White must get at least 7 stones in a row in order to win
— Even if White makes 8-in-a-row or more, it is not an overline and White does not lose the game. In fact, if at least 7 of the stones are in the central 15x15, White wins immediately
Suicide is forbidden, with the exception that a suicidal move which makes a winning 7-in-a-row is allowed, and wins the game
To all but perfectly balance the game as well as increase opening variety, Swap-2 and Swap-5 are available as Pie Rules
Proverbs
These are just some obvious ones to get started
As always, remember that proverbs always have exceptions, and are often formulated with brevity in mind. Explanations are given for each of these proverbs, but keep in mind that they may assume ideal conditions, and reading must take priority
- 6 is a win
- 6-in-a-row makes miai to extend to 7-in-a-row
- 5 is sente
- if ignored, 5-in-a-row can be extended to 6-in-a-row
- 4 orthogonally is sente
- if ignored, 4-in-a-row can be extended with a 1-point-jump, which the opponent must cut, and you don’t want to be forced to cut a 1-point-jump
- hollow is filled
- a hollow line (one which is missing 1 or more stones from the middle, but has stones on both ends) is often just as good as if it were filled
Where to Play
Abstract Play is where I recommend playing. You can accept an open challenge, make one of your own, join the ASTs, challenge players directly, or all of the above 
. All games are correspondence, so feel free to join in the fun without the stress of finding time to block out for a live game
I look forward to playing more Irensei with other OGFers
Customizing Stone Colors
As Go players, we all expect Black to play first and White second, and thankfully Abstract Play allows a large degree of color customization. Here is a short guide to making the stones Black and White:
Step by Step Intructions
Click on the options button in the upper right
Scroll down to the bottom and click on Manage Palettes
- Type #000 (or another dark color you prefer) into the box, and click Add Colour
- Type #fff (or another light color you prefer) into the box, and click Add Colour
- Give the palette a descriptive name (“go-stones” in this example)
- Click Add Palette
- Scroll down and click Save Changes
Click on Manage Color Contexts
Select Light Mode or Dark Mode depending on which one you use (or you can set color contexts for both modes)
For Dark Mode, set Borders Around Most Pieces to #fff (or another light color you prefer)
You can also play around with the other settings here, if you like
Scroll down and click on Save Changes
For Light Mode, set Borders Around Most Pieces to #000 (or another dark color you prefer)
You can also play around with the other settings here, if you like
Scroll down and click on Save Changes
Exit back to the main site
Go to any game of Irensei (the one linked here, for example, but any will do)
At the bottom-right of the board, click on the option icon (the one on the far right that looks like a gear)
Set Choose Color Scheme to Custom, and select your custom palette from the dropdown
Set Where Would You Like These Colors Applied to For All Irensei Games
Scroll down and click on Save
Refresh the page
Congratulations! you should have Black and White stones now!
