Play Pentago Online Free

Tomas Floden invented Pentago in 2003 during a meeting at the firm where he worked as an account analyst in Sweden. He built the first prototype from ordinary printing paper that same evening. The Swedish company Mindtwister published it in 2005, and it won the Mensa Select award in 2006. In 2014, Geoffrey Irving strongly solved the 6x6 version using a Cray supercomputer at NERSC, proving that the first player wins with perfect play across 3,009,081,623,421,558 possible positions. The game combines placement with a twist: after you place a marble, you rotate one of the four 3x3 quadrants 90 degrees. Line up five to win. Place a marble and make your first twist now.

1. You play the dark marbles and move first. Click any empty cell on the 6x6 board to place one marble. Before clicking, note which 3x3 quadrant contains the cell and where that marble would travel if the quadrant rotates.
2. After placement, choose one of the quadrant arrows to rotate that 3x3 section 90 degrees clockwise or counterclockwise when the turn requires a twist. Watch all nine cells move together while the center cell stays fixed.
3. Recheck the full board after rotation. A row may cross a quadrant boundary, and a twist can build or break lines for either color. Scan horizontally, vertically, and diagonally instead of following only the marble you placed.
4. Win by forming at least five dark marbles in an unbroken straight row. The line can sit inside a region of the board or span quadrants. A win can appear after placement or after the rotation resolves.
5. Continue until a player forms five or the game reaches a draw. If one rotation forms five for both colors simultaneously, neither side wins. If all 36 cells fill without a row of five, the board also ends in a draw.

• The board is a 6x6 grid divided into four 3x3 quadrants. Quadrant borders help players predict movement, but rows of five use the complete grid and can cross those borders.
• A standard turn has two actions: place one marble in any empty cell, then rotate one quadrant exactly 90 degrees clockwise or counterclockwise. A rotation moves the eight outer cells of that quadrant and leaves its center cell in place.
• This implementation makes rotation mandatory once no neutral quadrant remains. It treats an empty quadrant or a quadrant with only one center marble as neutral. While a neutral quadrant exists, the available turn handling follows that exception.
• A player wins by creating five or more same-color marbles in a straight horizontal, vertical, or diagonal line. The game checks after placement and rotation, so always look for an immediate line before evaluating the twist.
• If a rotation creates qualifying rows for both players at the same time, the result is a draw. A defensive twist therefore needs more than breaking one threat; it must also avoid completing an opposing line elsewhere.
• A full board without any row of five produces a draw. Marbles never leave play or change color. Rotation changes their coordinates, while placement steadily reduces the number of empty cells.

• Use quadrant centers as stable anchors. A center marble keeps the same coordinate when its quadrant turns, so lines can pivot around it without moving the anchor itself. Pair that stability with edge or corner marbles whose future paths you can predict, rather than filling centers without a connecting plan.
• Calculate each turn as placement plus rotation. First record the position after your proposed marble, then map the chosen quadrant in the chosen direction. Finally, inspect the opponent's strongest placement and twist. This three-position routine prevents a good-looking placement from becoming a harmful final board.
• Build threats across quadrant borders. A line segment that spans two sections may survive a rotation better than a cluster held in one section, although a twist can still move the cells inside its own quadrant. Use two directions when possible so one defensive rotation cannot answer every endpoint.
• Rotate defensively with a full-board scan. When the opponent shows four, identify which members of the line belong to a movable quadrant and test both directions. Choose a twist that breaks the row without assembling another light row or scattering the dark marbles that support your counterattack.
• Track corner and edge cycles. A corner moves to another corner after one quarter turn, while a non-center edge cell moves to another edge position. Mentally mark the destination before placing there. This habit lets you transport a marble into a line on purpose instead of treating rotation as a surprise.

• Gomoku: Gomoku keeps the goal of five in a row but never rotates the board. Every stone stays at its original intersection, so players focus on open ends, crossing threats, and blocks. Try it to isolate placement decisions from Pentago's moving coordinates.
• Pente: Pente adds custodial captures and a second victory route through captured pairs. Its board stays fixed, but stones can leave after a flank. Playing it shows another way a five-in-a-row game can make an apparently secure formation change.

• Every turn changes the position twice. Placement adds one fixed fact, then rotation reorders nine cells. That sequence gives players a clear calculation puzzle with enough movement to overturn first impressions.
• Stable centers and moving outer cells create useful visual patterns. Beginners can follow one quadrant cycle, while experienced players can coordinate lines across borders and compare several final positions before choosing an arrow.
• Pentago's solved status supplies mathematical context without deciding a human game in advance. Geoffrey Irving's 2014 result proves a first-player win under perfect play, while ordinary players still need to find effective moves at the board.
• The placement and twist controls make progress immediate. A player can understand a loss by replaying the final rotation mentally, then begin another game with a concrete correction such as checking both twist directions or protecting a cross-border line.

Play Pentago online for free on Clasica Games with quadrant controls and line detection built into the browser. Place a dark marble, preview which outer cells each arrow will move, and scan the resulting full board before choosing. The other player responds on the same device, giving both of you repeated practice with stable centers, corner cycles, defensive turns, and rows that cross quadrant borders. No physical board setup or manual rotation tracking is required.

Pentago rewards players who treat placement and rotation as one complete decision. Anchor useful centers, predict where corners and edges will travel, and inspect both colors after every twist. A row can appear far from the marble you just placed, so keep your attention on all 36 cells. Start a game above, test both rotation directions, and build a five-marble line that survives the changing board.

• Pentago is a First Player Win: Strongly Solving a Game Using Parallel In-Core Retrograde Analysis
• Q&A with Tomas Floden (Math Munch)