The Hexagon Game // Surrounder

Three weeks ago, I was sitting in a bathroom with hexagonal floor tiles. As I stared at the floor, I began thinking about geometric patterns involving hexagons. (I’m going to assume everyone does this until I hear otherwise, and if you tell me otherwise, I might refuse to listen.)

The thoughts went something like this:

What if these hexagons were one color? And those were another color? What patterns could you build?

And then:

Wait. What if, when one hexagon was surrounded by hexagons of a different color, it got “killed” and taken away? Like the hexagons were soldiers in some kind of horrible hexagon civil war? And the battle continued until every scrap of territrory was owned by one of the two sides?

After washing my hands, I power-walked back to my desk in the Yale Entrepreneurial Institute and began to prototype a board game. (This was long after the end of the workday, because the Institute is air-conditioned and contains fewer spiders than my house.)

After three games, I thought I really had something. After six games, I was convinced that the game was terrible. Then I expanded the board, and the cycle began anew. When things began to look really promising, I did some research on game design (which, in the tradition of Aaron research, included useful activities like reading the entirety of the manga Hikaru No Go and the biography of Christian Freeling).

Finally, I posted a picture of a finished game, and people were curious enough that I felt the game itself was worth blogging.

So, here it is. I call it “The Hexagon Game” inside my head, but a better, more Google-friendly name is “Surrounder”. I hope to hack together a playable app for it once my Javascript skills are up to snuff, but for now, I play in… Microsoft Paint. Such are the trials of game design.


Movement and Capture

The board is a grid of blank hexagons. Each side plays two hexagonal tiles per turn, anywhere on the board (they don’t have to be played next to each other).
Surrounder rules #1 (movement)

The black spaces at the top of the board represent the edge, rather than a series of black pieces.

You can capture an opponent’s hexagon, removing it from the board, by surrounding it — placing tiles so that more than half of the tiles surrounding the hexagon are of the opposite color. Capture is automatic — the tile is removed immediately.
  • If an opponent’s hexagon is away from the edge of the board, with six adjacent hexagons, you must surround it with four tiles to capture and remove it.
  • If an opponent’s hexagon is on the side of the board, with four or five adjacent hexagons, you must surround it with three tiles.
  • If an opponent’s hexagon is in a corner, with only two or three adjacent hexagons, you must surround it with two tiles.

Surrounder rules #2 (capture)

Pieces are captured instantly after the capturing tile is played: You can remove an opponent’s piece with your first move and then fill in the now-empty space with your second move.

Special Moves

You are free to play a tile in an area surrounded by your opponent’s tiles. If you would capture a stone by doing so, that capture occurs before your tile is captured. However, if your stone is still surrounded after your turn is over, it will be captured in return.
  • If you play a tile in this way and fail to capture an opponent’s tile, that is called “surrender” (you should not do this).
  • If you capture an opponent’s piece and are captured as a result, that is called “martyrdom” — typically a weak move, unless played near the end of the game.
  • If you play a tile in this way, capture an opponent’s piece, and avoid capture, that is called a “sneak attack” — sometimes, though not always, a strong move.

(Note: The terms I use here are kind of silly, and not really part of the game. Still, the game of chess has evocative terms, as does the game of Go, so I’ll follow their lead.)

New surrounder rules #3 (playing in enemy territory)


Winning and Losing

The game is over once the board has been completely filled. Generally, the final stage of the game sees both sides easily filling in spaces that are impossible for the opponent to invade. (As in the game of Go, players can stop the game early once it is obvious which territory belongs to each player.)


The winner is the side with the most territory — that is, filled-in hexagons of their color. In the diagram below, black has filled in 231 hexagons against red’s 219 hexagons. Black wins!
Game 1 (medium rectangle) (black plays, black wins 231-219)

At least one of Red’s territories looks like a flower. That’s almost as good as winning.

Sample Game

Here are some photos from a game in progress. It was played on a large board, 38 by 19 hexagons — twice the size of a typical Go board.


(I now think that board size is too big; I’m currently experimenting with 30×15, and the final board size might be more like 24×15.)


The early game:

 Red secures early control of the lower right-hand corner of the board, while Black dominates the lower left. Red seems certain to “connect” his two main territories, which is a powerful strategy. On the other hand, black’s “walls” on either side of the board give her strong influence over the center, where most of the unclaimed “territory” lies.
Game 1 (large rectangle) (early stage, black to play)

Black to play.

The middle game

Red has connected his two territories on the bottom of the board, but has failed to penetrate Black’s “walls” on the top of the board. The two sides have secured fairly even territory on top, but Black has surrounded a massive piece of the board on the center-right hand side. This is dangerous for Red, who will have a difficult time securing additional “empty space” to fill in at the end of the game. In fact, the game might be essentially “over” already; Red will need to fight hard in the center-right in order to win.

Game 1 (large rectange) (midgame)

Red to play.

The endgame

At this point, the excitement is over. Both sides have secured all the territory they can capture. Red could fight for a few tiles in black’s largest territories (center-right, upper-right corner), and Black could similarly attack the lower right corner, but none of those attacks will change the outcome of the game. Besides, Aaron was tired of playing against himself, so he decided to fill in all the spaces and call it a night.

Game 1 (large rectange) (before territory fill)

At this point, it doesn’t matter which player moves next.

The final position

Black wins 381-341, a fairly dominant victory. Decisive factors include red’s failure to break through in the center-right and his poor play early on in the lower left corner.

Hexagon game photo for Facebook

A few spaces in the final position haven’t yet been adjusted — this game was played with slightly different capture rules. But Black is the clear victor nonetheless.

Observations After Playtesting

Those are the rules of Surrounder — it’s quite simple to learn. It also seems deep; I learn new things with each game I play, and I very much doubt I’ve become “good” at the game yet.


The game is quite similar to a board game called Go, which is the oldest of all “territory games”. However, it differs in several important respects:

  • Entire “groups” of hexagons cannot be captured by becoming surrounded.  This makes it easier for one player to “invade” the territory of another player. You can’t protect an area simply by walling it off; in two moves, an opponent can build a formidable presence behind your walls.
  • Two tiles are played at the same time. This means that a single move can influence completely separate areas of the board. It also means that “tempo” — control of the flow of play — can quickly switch back and forth. Even if you threaten an opponent’s hexagon, she can defend her position and launch her own attack with her next move.
  • Because two tiles can be played at the same time, a lone hexagon is extremely vulnerable. If you place a tile away from your other pieces, the opponent can immediately play two tiles next to it, threatening an unstoppable capture. Therefore, most of your moves will involve the placement of tiles adjacent to your other hexagons. In Go, games tend to begin with many disconnected moves all around the board; optimal Surrounder strategy seems to focus more on early attacks, though I could be totally wrong about this.

Some potential weaknesses I’ve noticed in Surrounder:

  • It’s more complicated than Go, and far more complicated than chess. This isn’t always a virtue: So many moves are possible in any given situation that it may be impossible for humans to reach truly masterful play. (We’re still improving on Go strategy after over a millennium of serious play, and Surrounder lacks Go’s orderly, puzzle-like nature.)
  • The game mostly lacks the beautiful quality of Go wherein a single piece, placed many moves ago, can have tremendous importance in a combination much later. In Surrounder, these lonely pieces do help players carve out territory, but they don’t exert much “influence” outside of their immediate surroundings.
  • Still, early games have been interesting enough that I’d like to test Surrounder with other players. (Sometimes I pretend to be different people when I test the game, but that gets weird after a while.)

Bonus Puzzle: Red to Play

The last truly decisive move in the game above may have been in the following position, which I leave as a puzzle for the reader.

It is the start of Red’s turn: If Black responds correctly, is there any way that Red can form a “bridge” between his two territories? (Personally, I don’t think there is, but it’s likely that Red erred earlier in allowing the game to reach this position, where Black exerts just slightly greater control over the connection point. Had Red played differently 20 moves ago, things would have been completely different. It’s an enticing prospect!)

Hexagon game puzzle 1 (Red to play)


If you’d like to test Surrounder yourself, that would be amazing. I playtest in MS Paint, using the paint bucket tool to fill in spaces and white out captured pieces on the following boards:

Whether or not you enjoy the game, let me know what happens!

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