## Help for the Game of Caeth Y

### Introduction

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

CaethY challenge [-size=number] userid1 userid2

starts a new game between userid1 and userid2.

The -size parameter sets the number of vertices along an edge of the board. The default size is 9.

### Rules

The default Caeth Y board is as follows:
```                            1- *
2- / \
3- *-.-*
4- / \ / \
5- *-.-*-.-*
6- / \ / \ / \
7- *-.-*-.-*-.-*
8- / \ / \ / \ / \
9- *-.-*-.-*-.-*-.-*
10- / \ / \ / \ / \ / \
11- *-.-*-.-*-.-*-.-*-.-*
12- / \ / \ / \ / \ / \ / \
13- *-.-*-.-*-.-*-.-*-.-*-.-*
14- / \ / \ / \ / \ / \ / \ / \
15- *-.-*-.-*-.-*-.-*-.-*-.-*-.-*
16- / \ / \ / \ / \ / \ / \ / \ / \
17- *-.-*-.-*-.-*-.-*-.-*-.-*-.-*-.-*
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
A B C D E F G H I J K L M N O P Q
```
Players alternate turns, capturing an edge between two vertices on each of their turns.

When a player controls half or more of the edges leading into a vertex, they gain control of that vertex. (Specifically in Caeth Y: control of one edge into a corner vertex, two edges into a side vertex, or three edges into a centre vertex are enough for control.)

As in Y, the goal is to make a connected chain of vertices that touches all three sides of the board; the three corners count as members of both sides to which they are adjacent. Note that the connected chain is a chain of vertices, not of edges.

The second player may utilize the swap rule if they so desire.

### Move Syntax

Eks (X) moves first. The move syntax is:

CaethY move boardnum userid password coord

where coord is an unoccupied edge in the form L11.

will allow the second player to swap positions with the first player; this can only be done as the second move of the game.

### History

Caeth Y was discovered by Phil Bordelon in February 2004 as an application of the Caeth metarule to the game of Y. The original Caeth game used the same metarule applied to Hex; Caeth Y was an obvious extension of the concept.

There are two variations on the Caeth metarule which have to do with the way that vertices are owned; those are not currently implemented in this version of Caeth Y.

### Endnotes

Caeth Y was implemented by Phil Bordelon in February 2004 with the help of Richard Rognlie, Cameron Browne, and the author of the Game of Y implementation on the pbmserv.

The help file was written by Phil Bordelon in February 2004, with suggestions and a basic layout provided by Cameron Browne.