Open four
Four consecutive stones of the same color have an empty point at each end.
If your opponent cannot win immediately, blocking one end still leaves the other end for you to complete five in a row.
How to play gomoku — rules to your first tactics
Connecting your own stones is only part of the game: look for where your opponent can win, too. Compare Freestyle, Exact five and Renju, learn common patterns, then try them on the board.
Freestyle, Exact five and Renju: what changes?
These are the rules used in Gomoku Mate. Check which winning condition applies to your game before you start.
Black moves first on a 15×15 board, and players take turns placing one stone on an empty intersection. Only Renju forbids Black the double-three, double-four and overline. Renju · official opening adds the RIF regulation that keeps the first three stones near the center, White’s one chance to take Black, and a fifth move Black offers as two squares for White to pick from.
| Gomoku rules | Freestyle | Exact five | Renju |
|---|---|---|---|
| Five in a rowConnect exactly five stones of the same color horizontally, vertically, or diagonally, without a gap. | Wins | Wins | Wins |
| Six or more in a rowYou may make a longer line, but whether it wins depends on the ruleset. | Wins | This line alone does not win | Black loses, White wins |
| Double-three and double-fourThese moves create two open threes or two fours with a single stone. | Allowed for both colors | Allowed for both colors | Forbidden for Black |
Read the patterns and choose what comes first
First, check whether you can win on this move. If you cannot, stop your opponent's immediate win before building an attack. The patterns below use Freestyle rules.
Blocked four
Four consecutive stones of the same color have one end blocked by an opponent's stone or the board edge.
The remaining open end completes five, so check that point when attacking or defending.
Broken four
Four stones of the same color occupy a five-point line with a single gap between them.
Filling that gap makes five in a row, so check gaps as well as continuous lines.
Put the ideas to work in 8 exercises
Practice winning immediately, blocking one point, making an open four, and filling a gap, then explore attacks in two directions and early defense. Each exercise has a goal and hints, with an explanation after you play.
01Basics · PrioritiesWin now
Your stones · Black
Win on this turn without getting distracted by your opponent's threats.
Start every turn by asking, “Can I win now?” If you can, there is no need to defend.
Before each move: your win → opponent's win → create an attack.
Open tactics practice02Basics · DefenseDefend the one key point
Your stones · White
You are White this time. Stop Black from winning on the next move.
If your opponent's four stones have only one open end, block that end.
Look beyond your own stones. Check your opponent's last move and open ends too.
Open tactics practice03Intermediate · Open fourThreaten two points at once
Your stones · Black
Create an open four that guarantees a win on your next turn.
An open four has four consecutive stones with both ends empty. One move cannot block both ends.
Open space at both ends matters as much as the number of stones.
Open tactics practice04Intermediate · Broken fourThe power of one gap
Your stones · Black
Connect the scattered stones in one move to win.
Four stones do not have to be consecutive to pose a threat. Check whether filling a gap would make five in a row.
Check both continuous lines and lines with a single gap.
Open tactics practice05Applied tactics · Double fourTwo directions, one intersection
Your stones · Black
Threaten horizontally and vertically at once to secure a win on your next turn.
One stone can create a four in two directions. They must have different winning points to form two threats. This attack is legal in freestyle Gomoku.
Count distinct winning points, not just the number of threats.
Open tactics practice06Applied tactics · Defending an open threeDefend one move earlier
Your stones · Black
Stop White from creating an unstoppable open four on the next move.
An open three can become an open four if left alone. Blocking a point one space away is sometimes not enough.
Plan your defense while it is still an open three, before your opponent makes a four.
Open tactics practice07Applied tactics · Comparing threatsWhat matters more than a clever attack
Your stones · Black
Compare Black's attacking chances with White's threats and find a move that keeps you in the game.
Even a strong open four is too late if your opponent can make five now. Move order determines the strength of a tactic.
Before asking “Is this a good attack?”, ask “Can my opponent win first?”
Open tactics practice08Applied tactics · Finding spaceOpen ends create opportunities
Your stones · Black
Choose an attack that guarantees a win on your next turn.
The edge of the board acts like a blocked end. Even with the same four stones, an open four in the center creates a stronger threat for the next move.
Edge attacks can be useful too, but first compare the room to extend in both directions.
Open tactics practice09Renju · avoiding forbidden movesFive instead of a forbidden move
Your stones · Black
You are Black under Renju. The double-three square is tempting, but that square is forbidden. Find the move that ends the game now.
Renju forbids Black the double-three, double-four and overline. The more attractive the shape, the more often it is forbidden, so look for a line you can already complete before building an attack.
Strike forbidden squares off the list of candidates, and check the winning moves you already have first.
Open tactics practice10Renju · using the forbidden ruleA four that cannot be blocked
Your stones · White
You are White under Renju. Find the move that leaves Black a square it must block and may not play.
White has no forbidden squares, and Black can never occupy its own. Build a four whose winning point is forbidden for Black and there is no block left.
In Renju, White can use Black's forbidden squares as places Black cannot defend. Leaving those squares empty is the same idea.
Open tactics practiceThe 8 tactics exercises and Coach help use Freestyle rules. In Exact five, a line of six or more does not count as a win, and in Renju Black may not play a double-three, double-four or overline. AI previews show possible continuations; they do not guarantee the best move or a win.