Gomoku is an abstract strategy board game and is also called Five in a Row.
It is played with black and white stones on a 15x15 intersections board. Stones can not be moved or removed from the board once placed.
Black plays first, and players alternate in placing a stone of their color on an empty intersection. The winner is the first player to get an unbroken row of five stones horizontally, vertically, or diagonally.
The Gomoku Pro rule set some restrictions on the first few moves to reduce the advantage Black has by going first:
1. Black's very first move must be in the center of the game board.
2. White's first move can be anywhere.
3. Black's second move must be outside the five-by-five area in the center of the game board.
4. White's second move, and all moves after that, can be anywhere.
5. Win by placing exactly five stones in a row, six or more in a row does not win.
When play offline, you may choose whether use Gomoku pro rule or not. But when play online the rule is mandatory.
To place stone on board, just tap somewhere on board, a red square appears, move finger around to adjust the position of the red square, release finger when red square reach the destination. To reduce chance of misplace, you may set the option of "Place Confirm" to on, then after move around of red square, you need to tap the "Confirm" button below the board to place the stone.
In online play mode you can play with others over internet. After login you can join game tables created by others or create your own one. Password are required to join private tables. ELO rating system is used to calculate the relative skill levels of players, initially everyone have 1500 ELO. If you play with someone of lower ELO, you get less points if you win, but if you lost you lost more points, if the game reach a draw, you still lose points. But if you play with someone of higher ELO, the situation will be in contrast, you may get points even the game reach a draw. You'd better play with someone of ELO near yours.