## Help For the Game Of Quadrant Y

### Introduction

Welcome to the network Quadrant Y server. The rules of Quadrant Y are given below. The challenge command is described here. Other commands are the same for all pbmserv games.

Start a new game between userid1 and userid2

The -size parameter sets the overall board size. This must be an odd number in the range 5..31 (the default being 15).

### Rules

First let's recap the game of Y, which is played on a hexagonally tiled triangle. Two players, X and O, take turns placing a piece of their colour on an empty point, and the first player to connect all three sides with a chain of their colour wins. Eactly one player must win.

Quadrant Y is identical to standard Y except that in addition to the standard game the board is divided into four smaller triangles, each containing a subgame played according to the same rules. The perimeter of each subgame is marked '+' (subgames share borders with neighbouring subgames).

1- +
2- + +
3- + . +
4- + . . +
5- + . . . +
6- + . . . . +
7- + . . . . . +
8- + + + + + + + +
9- + + . . . . . + +
10- + . + . . . . + . +
11- + . . + . . . + . . +
12- + . . . + . . + . . . +
13- + . . . . + . + . . . . +
14- + . . . . . + + . . . . . +
15- + + + + + + + + + + + + + + +
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \
A B C D E F G H I J K L M N O

This gives a total of 5 pts: 1 pt for the standard game and 1 pt for each of the four subgames. A player wins the overall game as soon as they score 3 pts, which may involve winning the standard game plus at least two subgames, or winning at least three subgames.

### Example Game

The following example shows a game won by X.

+
+ x
+ x +
x x . +
o o x . +
+ x o x . +
+ . x o x . +
+ + + x o x + +
+ + . . x o x + x
x . + . x o o x x o
+ x . + x o . o o o +
+ . x x x o . x . . . x
+ . x o o o . + x x x x +
+ . x o . . + + . . . x . +
+ + x o + + + + + + + + x + +

Even though O has won the standard game by connecting all three sides (plus one subgame), X has won three of the subgames to give them 3 pts and the overall win. This can be demonstrated by examining each subgame in isolation:

+
+ x
+ x +
x x . +
o o x . +
+ x o x . +
+ . x o x . +
+ + + x o x + +

+ + + x o x + +
+ . . x o x +
+      + . x o o x      +
+ +      + x o . o      + x
x . +      x o . x      x x o
+ x . +      o . +      o o o +
+ . x x x      + +      x . . . x
+ . x o o o      +      + x x x x +
+ . x o . . +           + . . . x . +
+ + x o + + + +         + + + + + x + +

### Notes

Exactly one player must win Quadrant Y.

The central (upside down) triangle may appear to the the strongest subgame as it is the only one that touches all three sides. However, winning this central subgame does not necessarily help a player, as demonstrated by the above example.

Quadrant Y applies the principle introduced in Steven Meyer's game Quadrant Hex to Y. This principle constitutes a metarule that may be applied to a number of connection games. This metarule may also be recursively applied to any of the Quadrant game themselves, splitting each subgame into four subsubgames for a total of 16 + 4 + 1 = 21 pts up for grabs, and each subsubgame split further into four subsubsubgames for a total of 64 + 16 + 4 + 1 = 85 pts, and so on.

### Syntax

X moves first. The move syntax is: