Gomoku Variants: Renju Rules
Five in a row is the goal in every variant; the arguments start at the edges. This guide covers freestyle gomoku, renju rules, the swap opening protocol and overline handling, plus four things to confirm before the first stone.
Gomoku variants differ at the edges, not on the board: which shapes count as a win, which are forbidden, and whether sides can be swapped after the opening. Freestyle gomoku is the loosest set, renju adds forbidden moves for black, and protocols such as Swap2 stack a swap on top. This page goes through them in the order you would check before a match, so you can tell which one you are playing on the play page at yiboardgame.com.
Freestyle gomoku: the loosest set
Freestyle runs on three rules: black moves first, players alternate, and five in a row in any direction wins. Black may play double threes and double fours, and an overline of six or more still counts. It is the friendliest set for a first game because there is nothing to memorise. The downside is the same fact said another way: with no forbidden moves the first player has a forced win, and strong play turns into a memory contest over openings.
Renju rules explained: three bans on black
Renju restricts black only, and white keeps every option. Black loses on the spot for a double three (two open threes from one stone), a double four (two fours from one stone), or an overline of six or more. Black may still build a single open three, a single four, and win with exactly five. The test reads the shape on the board after the stone lands, not the intent behind it, so one stone that completes two live threes at once is forbidden even if you only meant one of them.
- Double three: one stone makes two open threes at once. Forbidden for black
- Double four: one stone makes two fours, including a mix of open four and straight four. Forbidden for black
- Overline: six or more in a row does not win for black, it loses. White may win with an overline
- Exact five: black wins only by making exactly five without breaking a ban
- White has no forbidden moves and may use double threes, double fours and overlines
Gomoku vs renju: what changes in your play
The sharpest freestyle move is one stone with two meanings, usually a double three where the defender can only cover one side. Renju makes that shape an immediate loss, so black has to stack threats one layer at a time. The four-three, an open four plus an open three from the same stone, becomes the cleanest win available: it breaks no rule and leaves a single defensive point. White's job shifts too, from dismantling one doubled threat to judging which of black's layers lands first.
Games run longer as well. Freestyle matches can end inside fifteen moves. Under renju, black spends more moves assembling a legal stack, so midgame reading carries more of the result. If you are arriving from freestyle, the habit to drop first is reaching for a double three the moment you see one.
Swap2 and the opening protocols that flatten the first move
- Swap: after black's first three stones, white may change sides, which pushes black toward a balanced opening
- Swap2: a second layer of choice on top of swap, so fixed opening traps lose most of their value
- Fixed opening placement: some rules put black's first stone on the centre point and restrict the second, cutting known winning lines
- Board size: 15x15 is the usual renju board, 19x19 shows up more in freestyle, and a larger board makes the first-move edge harder to cash in
Four things to confirm before the first stone
Default rules vary between platforms, and the set used on yiboardgame.com is listed on the gomoku rules page. Ten seconds on these four questions removes most arguments about whether a move actually won. Once the ruleset is fixed, the server referee checks every move, so nothing rests on goodwill.
- Does black have forbidden moves? If yes, you are on a renju set; if no, freestyle
- Does an overline count? For black it loses under renju, for white it wins
- Is there a swap protocol? With a swap in place, memorised first-player traps lose much of their edge
- Is the board 15x15 or 19x19? The size changes how quickly the first-move advantage converts
FAQ
What is the biggest difference between gomoku and renju?
Renju adds forbidden moves for black: double three, double four and overline all lose immediately, which offsets the first-move advantage. Freestyle has none of those and lets black use any shape.
Is renju gomoku harder than freestyle?
The rules are harder, the game is not necessarily. You memorise three exceptions and drop the habit of one stone doing two jobs. In exchange the first player loses the forced win and the match sits closer to fair.
Why does an overline of six not count as a win for black?
Overlines usually grow out of a double four or a double three. Banning them closes the path where black wins by stacking overlapping shapes. White is not restricted and can win with six or more.
Are Swap2 and renju the same thing?
No. Renju is a set of forbidden moves, Swap2 is an opening protocol for choosing sides. Formal renju events often use both: swap first, then play under the bans.