Welcome to the network Cross server. The challenge command is described here. Other commands are the same for all pbmserv games.
cross challenge [-size=number] userid1 userid2
Starts a new game between userid1 and userid2.
The -size parameter sets the number of cells per board side. This must be a number in the range 2..10 (default 6).
Start: The board is initially empty.
Play: O places one of their pieces at an empty cell then X may elect to swap colours in lieu of making the second move (swap option).
Players then take turns placing a piece of their colour on an empty cell.
Aim: A player wins by connecting three non-adjacent board sides with a chain of their pieces.
A player loses by connecting two opposite board sides with a chain of their pieces (without also connecting three non-adjacent sides).
Each corner cell belongs to both sides that meet there.
For example, the following boards show a game won by O (left) and a game won by X (right). Exactly one player must win every game.
. . o . . . . . o . . .
. . . o . . . . . . o . . .
. . . o . . x x . . . o . . . x
x x . . o x x . . . . . . o . x x .
. . x x o x . . . . . . . . o x x . . .
. . . . x o o . . . . . . . . x o . . . . .
. . . . o x o o . . . . x x . o . . . .
. . o o x . . o o x x . . o . . . .
o o . . x . . . . . . . o . . .
. . . x . . . . . . o . . .
. . . x . . . . . o . .
The move syntax is:
F6 Place a piece at coordinate F6, which must be empty.
swap X may elect to swap colours as their first play.
Cross rules copyright (c) Cameron Browne 2008.
The Cross rules were originally devised as a game using the Gates tiles that did not favour either player, however it was obvious that the rules constituted a fundamental connection game in their own right. They incorporate a mechanism similar to Yavalath in that players win by achieving a major connection but lose by achieving a minor connection without also achieving the major connection.
Cross is similar to Unlur but simplifies it; both players have identical goals and no extended contract phase is required.
Implementation and help file by Cameron Browne, June 2008.