AGA Rules
The AGA rules are the rules of Go adopted by the American Go Association.
They use area scoring, but pass stones are used so that the score can be counted by methods usually used for territory scoring[1]. A consequence of area scoring is that eyes in seki are added to the player's score.
They prohibit suicide.
(They are therefore quite similar to Chinese rules.)
They use the situational superko rule:
- It is illegal to play in such a way as to repeat a previous board position from the game, with the same player to play.[2]
In addition white must make the last play.
In theory the rules allow free placement of handicap stones, but in practice the traditional Japanese placement is usually used. This is mentioned in the commentary at http://www-2.cs.cmu.edu/~wjh/go/rules/AGA.commentary.html
The complete text of the rules can be found here: http://www.usgo.org/resources/downloads/completerules.pdf
Notice that the 1991 date in the above document is wrong: the rules were changed in August 2004, with komi set to 7.5 rather than 5.5, effective 2005; see point 9 in http://www.usgo.org/resources/downloads/2004-minutes.pdf
The French rules and the British Go Association rules are essentially the same as AGA rules.
[1] Territory counting (with pass stones) is used by default unless the players agree before starting play to another counting method.
[2] Robert Jasiek: Many readers of the rules text read it as if it were meant to describe situational superko (but the major author of the rules, Terry Benson?, insists that natural situational superko was meant).
Discussion
According to http://www.britgo.org/rules/aga.html the BGA has decided to adopt the AGA rules in october 2007. The document mentions that the board is proposing to get this change accepted (or denied) at the 2008 Annual General Meeting. Does anyone know if the 2008 AGM has already happened, and what the result was if it did? --Herman Hiddema
RobertJasiek: The AGM has taken place during the 2008 British Go Congress. The motion to adopt the AGA Rules has been accepted unanimously.
Herman Hiddema: Ok, thanks! I couldn't find anything about the AGM on the BGA website :-)