What is Connect6?
Connect6 is a five-in-a-row game turned up by one. It is played on a 19×19 board, and the first player to make an unbroken line of six or more stones of their colour wins.
The turn order is what makes it special. Black opens by placing a single stone. From then on, White and Black each place two stones per turn, anywhere on empty points. The two stones do not have to be next to each other. Because every turn adds two stones, whoever has just moved is at most one stone ahead, never more, and this is why Connect6 needs no swap or forbidden moves to be fair.
The game ends as soon as a line of six appears, even on the first stone of a pair. A full board with no line of six is a draw. In the table you place your two stones one after the other, and the turn passes to your opponent after the second.
Rule changes
| Rule | Standard Gomoku | Connect6 |
|---|---|---|
| Board | Standard Gomoku15×15 points. | Connect619×19 points by default. 13×13 and 15×15 can be chosen in the setup. |
| First turn | Standard GomokuBlack places one stone. | Connect6Black places one stone; this is the only one-stone turn of the game. |
| Stones per turn | Standard GomokuOne stone a turn. | Connect6Two stones a turn for both players after Black's first stone, placed anywhere. |
| How to win | Standard GomokuMake an unbroken line of exactly five stones. | Connect6Make an unbroken line of six or more stones. |
| Opening rules | Standard GomokuCan be combined with Swap2. | Connect6Not needed: the one-stone first turn already balances the game, so Swap and Swap2 are not used. |
History
Connect6 was invented in 2003 by Professor I-Chen Wu of National Chiao Tung University in Taiwan, who came up with it while playing five in a row with his daughter. He looked for a game in the five-in-a-row family that would be fair without complicated restrictions, and found that placing two stones a turn after a single first stone keeps both players even.
The game was presented to computer scientists in 2005 at the Advances in Computer Games conference in Taipei, and it soon became a regular event at the Computer Olympiad, where Wu's program NCTU6 won gold. Connect6 has since gathered players and tournaments of its own, mainly in Taiwan and China.