## Help for the Game of Octex

Welcome to the network Octex server. The challenge command is described here. Other commands are the same as for all pbmserv games.

octex challenge [-size=number] userid1 userid2

starts a new game for two players.

The -size parameter specifies the board size (default 5).

### Introduction

Octex is a 3D path-making game played with octagonal pieces.

### Rules

Tiles: Two players, O and X, share a common pool of octagonal tiles divided into four coloured regions:

```    ---      ---
/o|x\    /x|o\
|--+--|  |--+--|
\x|o/    \o|x/
---      ---  ```

The front and back faces of each tile have a square coloured bump that connects two opposite corners of that colour, giving four unique rotations:

```    ---      ---      ---      ---
/o|x\    /x|o\    /o|x\    /x|o\
|--o--|  |--o--|  |--x--|  |--x--|
\x|o/    \o|x/    \x|o/    \o|x/
---      ---      ---      ---  ```

Start: The board consists of an 5x5 grid of square holes which is initially empty.

Play: Players take turns placing a piece to nestle in either:
1) An empty board hole, or
2) The square hole formed where four tiles meet on the same level.

The following example shows a stacking move in which a tile is placed to nestle in the square hole formed by four mutually adjoining tiles. Note that that there is initially an X path running from top left to bottom right (left) but that the move breaks this path (right).

```    ---   ---              ---   ---
/x o\ /o x\            /x o\ /o x\
|  x  |  o  |          |  x --- o  |
\o x/ \x o/            \o /x o\ o/
---   ---    ---->     -|  o  |-
/x o\ /x o\            /x \o x/ o\
|  o  |  x  |          |  o --- x  |
\o x/ \o x/            \o x/ \o x/
---   ---              ---   ---
```

Aim: A player wins by forming an orthogonal or diagonal line of three bumps of their colour, such that a path of the same colour (not including any bumps) can be traced between the bumps at each end of the line. If a move achieves this for both players then the mover loses.

The following example shows a game won by X, who has formed a vertical line of three X bumps with a bumpless path between them:

```       +     +     +     +     +

---   ---
/o x\ /o x\
+     +  |  x --- x  |  +
\x /o x\ o/
---   -|  o  |-
/o x\ /x \x o/ o\
+  |  x --- x --- o  |  +
\x /x o\ x/ \o x/
-|  o  |-   ---
/o \o x/ x\
+  |  o --- x  |  +     +
\x o/ \x o/
---   ---

+     +     +     +     +
```

### Syntax

Place tile rotation B at position c3:
octex move board# userid password B:c3

### History

Octex tiles and rules by Cameron Browne and copyright (c) Cyberite Ltd 2008. Thanks to Stephen Tavener for suggesting the "N bumps in a row" winning condition.

The name Octex refers to the tiles having eight (oct) sides and six (hex) distinct coloured parts, in addition to the 'X' shaped colouring patterns on the tiles.

Official Octex rules: http://www.cameronius.com/games/octex/

Graphical web interface: http://www.gamerz.net/pbmserv/List.php?Octex

Implementation and Help file by Cameron Browne, October 2008.