## Help for the Game of Hextad

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

hextad challenge [-pool_size=number] [-min_pips=number] [-max_pips=number] [-strict|lenient] userid1 userid2

starts a new game for two players.

The -pool_size parameter specifies how many tiles each player has in their pool (default 7).
The -min_pips parameter specifies the minimum number of pips on any face (default 0).
The -max_pips parameter specifies the maximum number of pips on any face (default 6).
The -strict option specifies that every intersection formed must score points (default on).
The -lenient option specifies that not every intersection formed has to score points.

### Introduction

Hextad is a game played with hextiles in which players score points by forming triplets at intersections that add up to valid sums.

### Rules

Hextad is played with a complete set of 28 "double six" hextiles (hexagonal dominos) each showing a unique pip pair in the range 0 to 6.

Start: All tiles start off face down in the boneyard (unused tile set). Players take turns drawing a tile until a double is drawn, and this becomes the first tile played. Players each then draw their own pool of 7 tiles, which the opponent can see.

Play: Each turn, the current player must place one of their tiles adjacent to at least one existing tile. If the -strict option is used, then every intersection formed by the move must add up to a valid sum (explained shortly). If the player cannot move, they must draw tiles from the boneyard until they are able to move (no passing). After the move, the player draws a tile from the boneyard to replace the tile just played.

Scoring: Players score points for every valid sum formed by their move. A valid sum exists when the pip counts of three tiles meeting at an intersection can be arranged so that two of the pip counts add up to the third. The mover scores a number of points equal to the sum's value for each sum formed.

```       _____                   _____         _____                  _____         _____           /     \                 /     \       /     \                /     \       /     \        /  ooo  \               /  ooo  \_____/   o   \              /  ooo  \_____/  o o  \_____      /\       /              /\       / o o         /             /\       / o o         /     \    \ \     /               \ \     /  o o   _____/              \ \     /  o o   _____/  o o  \     \/     \     ---->      \/     \  o o  /____/     ---->      \/     \  o o  / o o         /     /  ooo  \               /  ooo  \_____/                      /  ooo  \_____/        _____/    /\       /              /\       /____/                      /\       /____/\  o o  /____/         \ \_____/               \ \_____/                            \ \_____/     \ \_____/     \/____/                 \/____/                              \/____/       \/____/

Start tile                3+3=6 (6 pts)                        2+4=6, 2+2=4 (10 pts)        ```

The largest possible score for any move is 60 pts.

Aim: The game ends when neither player has any move, typically when the tiles run out. The player with the highest score wins.

### Syntax

The move syntax is: