Isn't Black at an advantage?

Gomoku favors the first player. In free style, it is important for White to defend solidly. If you choose "with forbidden moves", Black cannot play double-threes, double-fours or overlines, which makes the first-player advantage smaller.

How is it different from Renju?

Renju is a competition rule set that limits the first-player advantage by giving Black forbidden moves. On this site you can play either simple free style or "with forbidden moves", where Black has forbidden moves (detailed competition rules, such as where the opening stones go, are left out).

Do I lose if I play a forbidden move?

On this site, you simply cannot play on a forbidden point. You never lose that way, so you can try things safely while you learn the rules.

Asobi Lounge / Games / Gomoku

Gomoku rules and how to play: free style or with forbidden moves

A simple game where Black and White take turns placing stones on a 15×15 board, and the first to line up five in a row vertically, horizontally or diagonally wins. You can choose free style, where you can play anywhere, or "with forbidden moves" (禁じ手あり), where Black has forbidden moves. Play against a CPU with four strength levels or with friends in a room match.

Players: 2 players (1 against the CPU)
Price: free
Runs in the browser (no install)

Play now

The game screen is in Japanese.

Games against the CPU and solo modes work right away without signing in. Online play (random matches and private rooms) and saving stats or leaderboard scores require signing in with a Google account. To play with a friend, your friend also needs to create an account and register as your friend.

Gomoku modes

Random match (ランダムマッチ): find an opponent online
Room match (ルーム対戦): play a friend using a room ID
Play against the CPU (CPU対戦): practice at four strength levels
Two players (ふたりで対戦): take turns on one screen

Basic rules of Gomoku

The 15×15 board starts empty, and Black moves first.
Black and White take turns placing one stone on an intersection. A stone never moves once placed, and it cannot be captured.
You win by making a line of five or more of your stones vertically, horizontally or diagonally.
In free style there are no forbidden moves. If you choose "with forbidden moves", Black cannot play a double-three, a double-four or an overline (six or more), and wins only with exactly five. White has no forbidden moves and also wins with six or more.
Even with forbidden moves, a move that makes exactly five wins for Black, even if it also forms a forbidden shape. Black may also play a four-three (making a four and a three at the same time).

How to play on Asobi Lounge

Click the intersection where you want to place a stone. On a phone, tap once to check the spot, then tap the same spot again to place the stone.
The last stone played has a red dot. Turn on "Show move numbers on stones" (石に手順を表示する) to see the order of moves on the stones.
With forbidden moves, points that would be forbidden for Black get a small × on Black's turn, and you cannot play there (so you never lose by playing one).
Against the CPU you can use Undo (待った) and up to three Hints (ヒント) per game. In an online rematch, Black and White switch.

How the CPU levels differ

Novice: blocks fours but often misses threes.
Beginner: blocks threes and never misses an open four. It plays on points with good shape.
Intermediate: reads a few moves ahead and looks for a win by making fours in a row (a four-chase).
Advanced: reads deeply and finds long four-chases. It also stops yours.

Shapes to know

Four: one more stone makes five. Your opponent must block it or lose.
Open four: a four that becomes five at either end. It cannot be fully blocked, so whoever makes it has won.
Three: one more stone makes an open four. Block one of its ends early.
Four-chase: a way to win by playing fours one after another, forcing your opponent to block each one, and finally making a four-three or an open four. Your opponent can only block each time, so if you read it through to the end, the win is certain.

Tips

Make a three with both ends open first; your opponent will have to block it.
If you make two fours in different directions at once (double-four) or a four and a three at once (four-three), your opponent can block only one of them.
Defense matters as well as attack: block your opponent's threes early.

Frequently asked questions

Isn't Black at an advantage?: Gomoku favors the first player. In free style, it is important for White to defend solidly. If you choose "with forbidden moves", Black cannot play double-threes, double-fours or overlines, which makes the first-player advantage smaller.
How is it different from Renju?: Renju is a competition rule set that limits the first-player advantage by giving Black forbidden moves. On this site you can play either simple free style or "with forbidden moves", where Black has forbidden moves (detailed competition rules, such as where the opening stones go, are left out).
Do I lose if I play a forbidden move?: On this site, you simply cannot play on a forbidden point. You never lose that way, so you can try things safely while you learn the rules.
Is Gomoku free to play?: Yes, it costs nothing. Games against the CPU and solo modes work right away without signing in. Online play (random matches and private rooms) and saving stats or leaderboard scores require signing in with a Google account. To play with a friend, your friend also needs to create an account and register as your friend.