About Go (Weiqi/Baduk)
Go, also known as Weiqi (围棋) in Chinese or Baduk (바둑) in Korean, is an ancient strategy board game that originated in China over 4,000 years ago. It is one of the oldest board games still played today and is considered one of the most complex and profound games ever created.
In Go, two players (Black and White) alternately place stones on the vacant intersections of a grid. The objective is to surround more territory than your opponent. Stones are captured and removed from the board when they are completely surrounded by the opponent's stones, having no empty points (called "liberties") adjacent to them.
This online version features a 9×9 board (a smaller, beginner-friendly size compared to the traditional 19×19 board) with three AI difficulty levels. Whether you're a complete beginner learning the basics or an experienced player looking for a quick game, this implementation provides an authentic Go experience with proper rule enforcement including ko rule, territory scoring, and stone capture mechanics.
How to Play Go
Go is played on a grid of black lines (the board). Game pieces, called stones, are played on the intersections of the lines. The standard board size is 19×19, but beginners often start with 9×9 or 13×13 boards.
Basic Rules:
- Placing Stones: Black plays first, and players alternate turns. On each turn, a player may either place one stone of their color on an empty intersection or pass their turn.
- Liberties: A liberty is an empty point adjacent (orthogonally, not diagonally) to a stone or group of stones. Stones need liberties to remain on the board.
- Capturing: When a stone or group of connected stones is completely surrounded (has no liberties), it is captured and removed from the board. The captured stones are kept to count as points at the end.
- Ko Rule: A player may not play a move that returns the game to the previous position. This prevents infinite loops.
- Passing: If a player believes there are no more profitable moves, they may pass. When both players pass consecutively, the game ends.
- Scoring: The player with more territory (empty intersections surrounded by their stones) plus captured stones wins. Territory is counted by the areas that a player's stones surround.
Game Controls
- Click to Place Stone: Click on any empty intersection to place your black stone
- Pass Button: Skip your turn if you don't want to place a stone
- Undo Button: Take back your last move (also undoes the AI's response)
- New Game: Start a fresh game on an empty board
- AI Difficulty: Switch between Easy, Medium, and Hard AI opponents
Strategy Guide
Opening Strategy (Fuseki):
- Corner Priority: Corners are easier to secure than edges, and edges are easier than the center. Start by playing in the corners (especially the 3-3, 3-4, or 4-4 points).
- Balance: Spread your stones across the board rather than concentrating them in one area. This gives you more influence and options.
- Don't Overextend: Keep your stones connected or within reasonable distance. Isolated stones are vulnerable to attack.
Middle Game (Chuban):
- Life and Death: Ensure your groups have enough space to create two "eyes" (empty intersections completely surrounded by your stones). Groups with two eyes cannot be captured.
- Territory vs. Influence: Balance between securing solid territory and building influence that can be converted to territory later.
- Attack and Defense: Attack weak opponent groups while strengthening your own vulnerable positions. Don't be afraid to sacrifice stones if it gains you a strategic advantage.
- Cutting and Connecting: Look for opportunities to cut apart your opponent's groups while protecting your own connections.
Endgame (Yose):
- Count the Score: Regularly estimate the score to know if you're ahead or behind.
- Largest Moves First: Play the moves that gain or save the most points (sente moves that also threaten something are particularly valuable).
- Secure Territory: Fill in any weak points in your territory and reduce your opponent's territory where possible.
- Know When to Pass: Once all profitable moves are played, pass to end the game.
AI Difficulty Levels
Choose from three AI difficulty levels to match your skill:
- Easy AI: Makes completely random legal moves. Perfect for absolute beginners learning stone placement and basic rules. Win rate: 90%+ for experienced players.
- Medium AI: Uses basic strategic heuristics including corner preference, edge play, and simple pattern recognition. Suitable for players who understand the rules and basic tactics. Win rate: 60-70% for intermediate players.
- Hard AI: Employs advanced heuristics including influence mapping, liberty counting, attack/defense balance, and tactical reading. Provides a genuine challenge for skilled players. Win rate: 30-40% for advanced players.
The History and Culture of Go
Go was invented in ancient China more than 4,000 years ago, making it one of the oldest board games continuously played to the present day. According to legend, the game was created by the Chinese emperor Yao (2337-2258 BCE) to educate his son Danzhu and improve his discipline, concentration, and balance.
From China, Go spread to Korea around the 5th century CE and to Japan by the 7th century. Each culture developed its own traditions and terminology around the game. In Japan, Go became highly professionalized during the Edo period (1603-1868), with the establishment of Go houses (schools) supported by the government. The strongest players were given the honorary title of "Meijin" (master).
Throughout East Asian history, Go has been considered one of the Four Arts of the Chinese Scholar, alongside calligraphy, painting, and playing the guqin (a traditional string instrument). Confucius mentioned the game, and it appears frequently in Chinese classical literature and art.
In modern times, Go has spread worldwide. The game gained international attention in 2016 when Google DeepMind's AlphaGo program defeated Lee Sedol, one of the world's top professional Go players, in a five-game match. This was considered a major milestone in artificial intelligence, as Go's complexity had previously made it resistant to computer mastery.
Today, Go is played by millions of people worldwide, with professional leagues in China, Japan, and Korea. Major international tournaments offer substantial prize money, and top players achieve celebrity status in East Asia. The game is also studied for its strategic depth and is used in fields ranging from military strategy to business planning.
Cognitive Benefits of Playing Go
Research has shown that playing Go regularly can provide numerous cognitive and psychological benefits:
- Enhanced Strategic Thinking: Go requires players to plan many moves ahead while adapting to changing board positions, strengthening long-term strategic planning abilities.
- Improved Pattern Recognition: Players develop the ability to recognize complex patterns and situations, a skill that transfers to other domains like mathematics and science.
- Better Decision Making: The game teaches players to evaluate multiple options, assess risk vs. reward, and make decisions under uncertainty.
- Increased Concentration: A single game can last hours, training sustained focus and attention to detail.
- Creativity and Intuition: Unlike chess, where positions can often be calculated precisely, Go requires intuition about influence and potential territory, fostering creative thinking.
- Emotional Control: Players must remain calm when behind and humble when ahead, learning to manage emotions during competition.
- Social Connection: Go creates bonds between players across cultures and generations, with a rich tradition of post-game analysis and mutual learning.
Competitive Go
Go has a vibrant competitive scene worldwide:
- Professional Rankings: Professional players are ranked from 1-dan (lowest professional rank) to 9-dan (highest). In some countries, there's also a 10-dan honorary rank.
- Major Tournaments: Top events include the Ing Cup, Samsung Cup, LG Cup, and the World Go Championship. Prize pools can exceed $1 million USD.
- National Leagues: China, Japan, and Korea each maintain professional leagues with regular league matches and playoffs.
- Amateur Rankings: Amateur players are ranked from 30-kyu (beginner) to 1-kyu, then 1-dan amateur onwards. The amateur dan system continues above the professional entry level.
- Online Play: Platforms like OGS (Online Go Server), KGS, and Tygem connect millions of players worldwide for ranked and casual games.
Tips for Improving Your Go Skills
- Study Joseki: Learn standard corner sequences (joseki) to build a foundation of good opening moves.
- Solve Life and Death Problems: Practice tactical puzzles (tsumego) to improve your reading ability and group survival skills.
- Review Your Games: After each game, especially losses, review to identify mistakes and missed opportunities.
- Play Regularly: Consistent practice is more effective than occasional intense sessions. Even 1-2 games daily will show results.
- Learn from Stronger Players: Play against opponents slightly better than you and study professional games to see high-level concepts in action.
- Read Go Literature: Books like "Learn to Play Go" series, "Lessons in the Fundamentals of Go," and "Attack and Defense" provide structured learning.
- Join a Go Club: Many cities have Go clubs where you can play face-to-face, receive teaching, and enjoy the social aspect of the game.
- Use Teaching Games: Playing with handicap stones against stronger players while receiving live commentary accelerates learning.
Go Variants and Board Sizes
While 19×19 is the standard for competitive play, Go can be played on various board sizes:
- 9×9 Board: This version (featured here) is perfect for beginners and quick games. A full game typically lasts 15-30 minutes. It emphasizes fighting and tactics over large-scale strategy.
- 13×13 Board: An intermediate size that balances the strategic depth of 19×19 with the faster pace of 9×9. Games usually last 30-60 minutes.
- 19×19 Board: The standard tournament size, offering maximum strategic complexity. Professional games can last 3-8 hours.
- Variations: Some players experiment with non-square boards, different rule sets (Chinese vs. Japanese scoring), or special handicap arrangements for teaching games.
Why Play Go Online?
- Always Available: Play anytime without needing another person or physical equipment
- Immediate Feedback: The game enforces rules automatically and shows captures instantly
- Skill Development: Practice against AI of varying difficulty to gradually improve
- Quick Games: 9×9 games are perfect for short breaks or learning sessions
- Learn at Your Own Pace: No pressure from opponents, take time to think about each move
- Free and Accessible: No cost, no registration required, play directly in your browser
- Cultural Connection: Experience a game that has been played for 4,000 years and connects millions of people worldwide
Frequently Asked Questions
How do I win at Go?
You win by controlling more territory than your opponent. Territory consists of empty intersections surrounded by your stones, plus any stones you've captured. When both players pass consecutively, the game ends and the score is calculated. The player with the higher score wins.
What happens when stones are captured?
When a stone or group of connected stones has no liberties (empty adjacent points), it is captured and removed from the board. The captured stones are kept by the opponent and count toward their final score. In this game, you can see your capture count displayed next to each player's name.
What is the ko rule and why does it exist?
The ko rule prevents infinite loops in the game. It states that a player cannot make a move that would return the board to its exact previous position. This typically occurs when players could repeatedly capture and recapture a single stone. The ko rule forces variation in play and prevents the game from stalling.
Why should I play 9×9 instead of 19×19?
The 9×9 board is excellent for beginners because games are shorter (15-30 minutes), easier to read, and focus on fundamental tactics like capturing and life/death. It's perfect for learning basic concepts before advancing to larger boards. Even experienced players enjoy 9×9 for quick practice or blitz games.
Can I play Go on mobile devices?
Yes! This Go game works on all modern mobile devices including smartphones and tablets. The game canvas automatically adjusts to your screen size, and you can tap intersections to place stones. For the best experience on smaller screens, play in landscape orientation.
What's the difference between Chinese and Japanese Go rules?
The main difference is in scoring. Chinese rules count territory plus stones on the board, while Japanese rules count territory plus captured stones. This implementation uses a simplified scoring system similar to Chinese rules. In most games, both systems produce the same winner, though the point difference may vary slightly.