Go is "an ancient oriental board game for two players that is noted for being rich in strategy despite its simple rules." I tried to learn Go recently, and it was a rich and rewarding personal experience to struggle with my inability to play at even a novice level. I received a lot of great feedback about that post, including a nice comment from Dave Peck, who pointed me to his weekend project, Dave Peck's Go.
The sense of adventure in finding things out can be experienced in many different ways. Learning to play less poorly is one way. Another is to write a game playing algorithm, something that has fascinated me since I wrote a Maharajah and the Sepoys playing game in BASIC back at St. Andrews' College in 1977. A third is to write a server that adjudicates play between two humans. This is clearly less difficult but still provides opportunities for creativity and expression, which is why it is a favourite interview question.
So, here is "Wood & Stones," a pass and play local web application that adjudicates a game of Go between two players. This is an ongoing work, with both feature design, UX design, and software design changing on an almost daily basis. That is a long-winded way of saying that IMHO the code is nearly complete crap. It is as if you picked up an architect's sketch pad and looked at a page to find it covered with scribbles and cross-outs.
This is written specifically for the iPad at this time. I also test it on OS X Safari. Updated stylesheets for the iPhone/iPod Touch are in the works. I have made no attempt to test it on any other OS or browser. This is a pass-and-play application: It's for playing face-to-face with someone, not for playing the computer or playing with someone over the Internet (Issue 250). It turns an iPad into a portable go board that knows something about legal moves, can set up pieces for you, and allows you to go back and review the game.
To start a new game, open Wood & Stones using your iPad (it used to work just fine on iPhone, but I haven't gotten around to selecting the correct style sheet depending on whether you're on an iPhone or an iPad. Issue 275!):
If you want, you can give nicknames for each player. If you don't, you will be "Black" and "White" respectively.
Choose game to play, a board size, and setup. "Classic Go" is exactly what you think it is. The other options are why I had the stones to call this "Wood & Stones." Click "play" and you can start your game.
In direct violation of The Design of Everyday Things, Wood & Stones is an experiment with removing the visible affordances in the User Interface. I am trying to make as much as possible work with gestures like swiping the screen or drawing simple symbols.
When it's your turn to play, tap the intersection where you wish to play a stone. If your play kills any of your opponent's stones, they will fade from sight. If you like your play, pass the iPad to your opponent and it's their turn. If you don't like your play, "scrub" the board by swiping rapidly from left to right to left three or more times. It will be your turn again and you can tap a different intersection. You can undo multiple times if you want.
To pass, draw an "X" using three continuous strokes of your finger:
If it is the second pass, you will be asked to confirm that you wish to end the game. Yes, you can scrub to undo a pass. If a game ends with two passes, it's up to you and your opponent to figure out who won.
history and info
If you would like to see a history of the game, you move backwards in time by swiping from left to right. This is like moving the film so that the past becomes visible. Each swipe from left to right moves back one move. You can move forward in the history by swiping from right to left. Once you have returned to the current move, swiping right to left does nothing further.
You can see the game's current status by swiping towards the bottom of the screen:
The game info will slide down from the top of the screen:
To go back to the play of the game, swipe towards the top of the screen:
zooming and dragging
With larger boards, it can be a challenge to tap the correct stone location on an iPhone or iPod Touch. To zoom in, hold your finger or mouse down on the board. After a moment, the board will zoom. While zoomed in, you can tap to place a stone or drag the board to pan it around. When zoomed in, you cannot go back or forward in the history as the swipe becomes a pan. To zoom back out, hold your finger or mouse down again.
On multi-touch devices, you can also use the pinch gesture to zoom in or out.
The application is specifically written to support other games, most of which are documented on Sensei's Go Variant Page. Each game offers a variety of setup options. The most 'normal' games to the Go player are those that have the exact same rules and victory conditions, namely territory plus captures. They differ only in how the board is set up at the beginning of play.
Classic: This is the standard game of Go with the standard options for setup: Either black plays first, or black is awarded a handicap of between two and nine stones and white plays first. Handicap stones are placed on the Hoshi points in the conventional manner. Wood & Stones does not score the game but it will end the game after two consecutive passes.
Free Placement: This is also the standard rules for Go, however if black is granted a handicap, black plays the stones wherever he likes rather than having them placed on the standard Hoshi points. For example, if black is given a handicap of three stones, he will play the first three moves in a row and then white will play and the turns will alternate in the normal fashion for the remainder of the game.
More Setups: Once again the rules are the standard rules of Go, however the initial setup differs radically from tranditional Go. The options include:
Pie Rule: Black plays a single stone first. White has two choices. If he plays a stone, the game continues normally. However, white can also swap places by drawing a circle on the board with his finger. The two players switch colours, and the player who was originally black is now white and the player who was originally white is now black. The effect of this rule is that Black does not wish to make too strong an opening play for fear that white will choose to swap. Likewise, black does not wish to make too weak a play either, so he should make a play that ideally is perfectly balanced.
Wild Fuskeki: This is a standard game, however the first three moves are randomly chosen for each player. Black can have up to six randomly placed handicap stones. Initial positions will never include dead stones, ataris, or stones placed in either of the two edge rows or columns. Wild Fuseki discourages extensive memorization of opening play sequences and encourages strong fundamental style. (Really Wild Fuseki is exactly the same thing, however twelve stones are placed for each player.)
Influence Go gives each player opposing edges of the board. This game usually involves a fight to secure the center and establish a connection to your strong sides.
Dots Go consists of stones on alternate intersections of the board. Games evolve very differently than standard Go.
Sunjang Baduk is an archaic Korean version of Go. There is a prescribed opening position, and the scoring is a little different from Japanese or Chinese go. Even if you don't care to play with different scoring, you might find games with the Sunjang Baduk opening setup a refreshing change of pace.
Classical Chinese Opening go players started each game with two stones each on corner Hoshi points, leading to fighting. Classical Chinese rules were also different, however choosing this option starts a standard game of Go with the Classical Chinese Opening.
Some games have standard rules but different victory conditions. A number of these games share the common theme of a struggle for white to survive against crushing odds. In these games, white wins if he can create life. Black wins the moment there are no white stones on the board.
Corner Go is a corner invasion exercise: Only one corner is available to White. Corner Go works well on small boards.
Shape Go gives Black unkillable stones all the way around the board, and white has to try to make life with no corners or edges. Best on larger boards.
In the Kill-all game, black is given a large number of free placements and white simply tries to survive. An even game is thought to be seventeen placements on a 19x19 board, however you can choose more or fewer to establish a handicap. You may also choose a smaller board and fewer placements.
Atari Go uses normal rules on a 9x9 board, however the winner is the first to capture an opponent's stone. There is a progression of teaching setups given with the student playing black. The final setup, Cross-cutting, should lead to successive draws. When a student can always draw in this situation, they can move up to Capture Five.
Capture Five uses normal rules on a small board, however the winner is the first to capture five stones. This introduces the idea of sacrifice into the game. It is a natural progression from Atari Go.
Irensei is a game with standard Go rules, however captures and territory are irrelevant to scoring. The winner is the first player to make an unbroken line of seven stones in a row, although a line with stones within two intersections of the edge does not count. Black plays first, and to counter this advantage there is a special rule that black loses if he makes a line of eight or more stones. White can make a line of any length.
In Gonnect, the winner is the first to connect either pair of opposite sides of the board with a single group or a player loses when he has no legal move available. Passing is not allowed. This difference from normal Go is crucial, as it prevents a deadlock where neither player can connect: each player must eventually fill in their territory until they are vulnerable to capture or have no legal moves available.
In One Eyed Go, suicide is never allowed, even if your play would otherwise capture stones. One consequence of this simplification of the rules is that a single eye is enough to make a group safe.
This is my first jQuery project, and it shows. I'm also using jQTouch, although I'm using less and less of it as I get more comfortable with Mobile Safari. I've picked up a few other jQuery plugins, including my own iGesture for gestures like swipes and scrubs.
(c) 2010 Reg Braithwaite. All rights to the entirety of the program and the parts I have written are reserved with the exception of specific files otherwise licensed. Other licenses apply only to the files where they appear. This may change in time, check back.
Exemptions include iGesture and Dragscrollable, which I have licensed under the MIT license, plus various jquery plugins written by others.
All of the images used in the main game board are modified versions of files Dave Peck found on the Wikimedia Commons. These are distributed with the Creative Commons Attribution 2.0 ShareAlike license. Some other images were hand-drawn by Dave Peck, who put them under the Creative Commons Attribution ShareAlike 2.0 license: http://creativecommons.org/licenses/by-sa/2.0/