For the rules of go, see GameHelpClassicGo
Go strategy is extremely complex and well-studied, so we won't try to cover more than the basics. You can find more at external sites like Sensei's Library.
Fundamentals of Go
In his book Lessons in the Fundamentals of Go, Toshiro Kageyama says:
"After you have learned the rules, your first step should be to just play for a while (...) a number of games, say fifty or a hundred. During this period, if you see an enemy stone, try to capture it, try to cut it off. If you see a friendly stone, try to save it from capture, try to connect it. Concentrate on this alone as you build up some practical experience. (...) You cannot expect to do all your studying and gain all your knowledge from books."
Playing on the 9×9 board is a great way to finish games and learn lessons more quickly.
- A stone is connected to another stone if they are on directly adjacent grid intersections.
- Or if they are close together and the opponent cannot prevent them from becoming connected.
- Playing moves in between opponent's stones to prevent them from connecting is called cutting.
- Evaluating whether stones are connected or can be cut is a skill that is difficult at first, but becomes easier as you play more games.
- Stones that are connected form a group.
- Groups take many more moves to capture than isolated stones; this is why learning to connect your groups and disconnect your opponents' is so helpful.
Life & Death
Life and death is an important concept:
- A group with two eyes (two or more small territories) is alive, because the opponent can't fill up both eyes at the same time, and therefore the group cannot be captured.
- Most groups with one big territory/"a lot of eyespace" are alive: if the opponent tries to play inside, the group can inevitably form two eyes and capture the invading stones.
- A group that can inevitably connect to another alive group is alive.
- A group is dead if the opponent can inevitably capture it. Dead groups are cut off from all friendly groups, cannot capture the cutting stones, and do not have enough space to form two eyes.
- A group that is neither alive nor dead is unsettled.
- If you see a group of yours or your opponent's in immediate danger, move to defend or attack it. This is called an urgent move. You will miss urgent moves as a beginner, but you will get better at seeing them as you play more. Look for stones that can be cut off from their friends, especially if they don't have space to make eyes.
- If there are no urgent moves, play a big move that stakes out a large territory, or reduces an opponent's large territory.
- On the 19×19 and 13×13 boards, it is efficient to play near each of the corners first, then each of the sides, then the middle. It takes more moves in the center or the sides to surround the same amount of territory (and eyespace) in the corner. On the 9×9 board, however, starting near the middle is a good option, since the middle is close to multiple sides and corners.
- The line on the edge of the board is called "the first line". The line one intersection away from the edge is called "the second line". Most stones at the beginning of the game should be played on the third or fourth lines: the second line surrounds too little territory, and the fifth line is "too high" to help much on the side or corner. For reference, the circular "star points" are on the fourth line.
- If you see that a group of stones is unconditionally dead or unconditionally alive, don't waste moves trying to capture or save it: play somewhere else. Life/death evaluation takes practice; you can search online for beginner life and death problems to practice this if you want some fun puzzles!
- Don't worry about losing individual stones. You get another one every turn. The most important individual stones are "cutting stones" that are preventing two weak groups from connecting.
- You don't necessarily have to respond locally to your opponent's move. Often it isn't a threat, or there's something more important elsewhere.
- Before playing a move in complicated situations, consider a move that your opponent might play in response, and maybe the move that you will play after. This skill is called reading, and it is useful in many board games! Reading helps you to find the best move in complicated situations. You can practice reading in games, especially 9×9, or with life and death problems. Reading will become easier for you as you practice it, and as you become more familiar with the game of Go.
- If you're not sure what move to make, it's best to just play some move, go back after the game, and figure out a better move for next time. You will learn a lot faster, especially if you are playing on 9×9. Many experienced players are happy to discuss games with newer players when the game is over.