National variants[edit]
The difficulty in defining the rules of Go has led to the creation of many subtly different rulesets. They vary in areas like scoring method, ko, suicide, handicap placement, and how neutral points are dealt with at the end. These differences are usually small enough to maintain the character and strategy of the game, and are typically not considered variants. Different rulesets are explained in Rules of Go.
In some of the examples below, the effects of rule differences on actual play are minor, but the tactical consequences are substantial.
Tibetan Go[edit]

The starting position for Tibetan Go
Tibetan Go is played on a 17×17 board, and starts with six stones (called Bo) from each color placed on the third line as shown. White makes the first move.[1] There is a unique ko rule: a stone may not be played at an intersection where the opponent has just removed a stone. This ko rule is so different from other major rulesets that it alone significantly changes the character of the game. For instance, snapbacks must be delayed by at least one move, allowing an opponent the chance to create life. Finally, a player who occupies or surrounds all four corner points (the 1-1 points) receives a bonus of 40 points, and if he controls the center point also, he receives a further bonus of 10 points.
Sunjang Baduk[edit]
Main article: Sunjang baduk

The starting position for Sunjang Baduk
Sunjang baduk is a different form of Go (baduk) that evolved in Korea. It has been played since at least the 7th century. Its most distinctive feature is the prescribed opening. The starting position dictates the placement of 16 stones (8 black, 8 white) as shown, and the first move is prescribed for Black at the center of the board.
At the end of the game, stones inside friendly territory, which are irrelevant to boundary definition, are removed before counting territory.
Bangneki[edit]
In another Korean variant, bangneki, the players wager on the outcome of the game. A fixed stake ("bang") is paid for every ten points on the board by which the loser is beaten.[2][3]
Batoo[edit]
Main article: Batoo
Batoo is a modern Korean variant. The name stems from a combination of the Korean words baduk and juntoo (“battle”). It is played entirely in cyberspace, and differs from standard Go in a number of ways, most noticeably in the way in which certain areas of the board are worth different points values. The other principal difference is that both players place three stones before the game begins, and may also place a special “hidden stone”, which affects the board as a regular stone but is invisible to the opponent. Batoo became a short-lived fad among young people in Korea around 2011.
Variants altering the rules of play[edit]
First Capture[edit]
Main article: Capture Go
The first player to capture a stone wins. It was invented by Japanese professional Yasutoshi Yasuda, who describes it in his book Go As Communication. Yasuda was inspired by the need for a medium to address the problem of bullying in Japan, but soon found that "First Capture" also works as an activity for senior citizens and even developmentally delayed individuals. He sees it as a game in its own right, not just as a prelude to Go, but also as a way to introduce simple concepts that lead to Go. For the latter purpose, he recommends progressing to "Most Capture", in which the player capturing the most stones wins. This variation is often called Atari Go in the West, where it is becoming increasingly popular as a preliminary means of introducing Go itself to beginners, since, afterward, it is natural to introduce the idea of capturing territory, not just the opponent's stones.
Stoical Go[edit]
In Stoical Go, invented by abstract game designer Luis Bolaños Mures, standard ko rules don't apply. Instead, it's illegal to make a capture if your opponent made a capture on his previous move. All other rules are the same as in Go. Suicide of one or more stones is not allowed, and area scoring is used.[4]
All known forced Go cycles are impossible with this rule. The nature of the rule itself suggests that forced cycles are either impossible or astronomically rarer than they are in Go when the superko rule is not used.
Ko fights proceed in a similar manner to those of Go, with the difference that captures and moves answered by captures aren't valid ko threats. On the other hand, snapbacks are not possible, as it is necessary to make a ko threat before any consecutive capture occurs.
Coupon Go[edit]
Invented by Elwyn Ralph Berlekamp, Coupon Go compels the players to make quantitative decisions.[5]
Environmental Go[edit]
Environmental Go, invented by Elwyn Berlekamp, adds an element of mathematical precision to the game.[6] In lieu of playing a stone, a player may take the highest remaining card from a pack of cards valued in steps of ½ from ½ to 20: the player's score will be the territory captured, plus the total value of cards taken. In effect, the players participate in a downward auction for the number of points they think sente is worth at each stage in the game. The professional players Jiang Zhujiu and Rui Naiwei played the first Environmental Go game in April 1998. Since then the variant has seen little activity on the international scene.
Time Is Money Go[edit]
Each player begins the game with a decided upon amount of time (no byoyomi). At the end of the game, when the score is counted, the number of seconds remaining on each player's clock is added to his or her respective score.
Cards Go[edit]
In Cards Go players draw from a pack of cards contain instructions to play one of a fixed set of commonly occurring shapes.[7] If the said shape cannot be placed on the board, then an illegal move is deemed to have been played, which necessitates resignation.
Multi-player Go[edit]

A game of Go with stones of different colors
In Multi-player Go, stones of different colors are used so that three or more players can play together. The rules must be somewhat altered to create balance in power, as those who play first (especially the first four, on a four-cornered board) have significant advantage.[8]
There are various optional rules that enable cooperation between the players, e.g. division of captured stones among neighbors, or forming alliances for adding up territory points.[8] A variant called parallel multiplayer go also exists, where the moves are announced simultaneously. If two moves overlap, they count as passes.[8]
Paper and Pencil Go[edit]
Paper and Pencil Go is a Go variant that can be played with just paper and pencil.[9] Unlike standard Go, games played under these rules are guaranteed to end in a finite number of moves, and no ko rule is needed. Nothing is ever rubbed out. It differs from standard Go in the following ways:
Surrounded stones are not captured, but just marked. Points occupied by marked stones count as territory for the surrounding player, but neither player can play on them for the remainder of the game. This implies that any group which touches a marked stone is unconditionally alive.
Suicide is allowed, i.e., you can make a play such that one or more of your own stones become marked.
Area scoring is used.
(Conventional Go can also be played on paper by drawing circles of different colors. Captured stones are marked with a line. Then if the square is replayed, a smaller circle is placed inside the larger circle.[10])
Omino Go[edit]
Also named Tetromino Go. Devised by R. Wayne Schmittberger, each player is allowed to play up to four stones in a turn, provided they are solidly connected on adjacent points. (There are five four-stone patterns possible, two three-stone patterns, and one two-stone pattern, ignoring rotations and reflections.) There is no komi; Black is restricted on his first turn to playing no more than two stones. The winner is determined by Chinese scoring: occupied and surrounded points each count 1 point; captured stones do not have point value. The inventor suggests a 15×15 square-celled board using square-tiled pieces.[11]
NoGo[edit]
The first player forced to capture one or more stones or to make a suicide move loses.
KillAll Go[edit]
In this variant, black is given a large handicap, and must prevent white from forming a stable group.
Variants for more than two players, but not altering the mechanism of the game[edit]
Rengo[edit]
This involves two teams of players taking either the Black or the White stones. Each player in the team must play in turn, playing out of sequence will normally result in a small penalty (usually three prisoners). Partners may not consult on how to play, or engage in any form of signaling. Communication between partners may only take the following forms listed below.
May we resign? can be answered with yes or no
How much time is left? can be answered with coded instructions for the next move. For example, the response 5 minutes and 13 seconds could be a hint to play at the co-ordinates 5-13.[citation needed]
Whose turn is it?
Pair Go[edit]
Pair Go is a gender specific form of Rengo, calling for teams composed of one male and one female member.[12] It was popularised by the Japan Pair Go Association as a means of increasing female participation in the game. They hoped that this increase in itself would add a new appeal to the game. The Ricoh Cup, the annual professional Pair Go world championship debuted in 1994.[13] The International Pair Go Association sponsors an annual amateur world championship in Tokyo in November, which has been running uninterrupted since 1989.[14] They first introduced the variant to Europe at the 1992 European Congress in Canterbury, England. Amateur Pair Go tournaments have been held in the United States at U.S. Go Congresses since 2005 at least [15] and in Denver, CO.
Variants requiring memory of the position[edit]
Blind Go[edit]
One (as a handicap) or both of the players cannot see the board in this variant. Therefore they have to remember the whole position. This is considered much more difficult than playing blind chess. Indeed, most club standard players can play blind chess[citation needed], but only professional players are able to complete a game of blind 19×19 Go.
One Color Go[edit]
Both players use stones of the same color. This variation is regarded as a useful tool for developing one's reading skills.[clarification needed]