NAME¶

xquarto - X version of a simple but tricky board game

RULES¶

The board is made up of 4x4 squares and 16 pieces. The pieces carry 4 properties each, namely:

o Black or brown

o Horizontal or vertical

o Solid or hollow

o Round or square

This makes a total of 16 possible pieces and there are exactly one piece of each type (so each piece can be represented by a binary number of length 4).

Initially, the board is empty and it is successively filled with pieces. The game is over when a row, a column or a diagonal has four pieces carrying a common property in it, e.g. four black (brown) pieces, four square (round) pieces, four solid (hollow) pieces, four horizontal (vertical) pieces. In the original quarto rules, the player who is the first to complete a row, column or diagonal as described above wins. This is the implicit mode under which Xquarto runs. A variant of the game (tic rules) consists rather of avoiding alignments, i.e. the player who is forced to complete an alignment loses.

The game is a two-player game. Player 1 chooses one of the 16 pieces. Player 2 then places this piece on one of the 16 squares of the board and chooses a piece out of the remaining 15 pieces which he gives to player 1, who places this piece on one of the remaining 15 squares on the board, etc...

Xquarto supports three different player combinations: human vs computer, computer vs human and human vs human (possibly through the local network in the latter case). The default combination is human vs computer, i.e. the human player starts the game against the computer. This can be changed by clicking on the "Actions" menu (see below for more details).

MENU COMMANDS¶

There are two menus, the 'Actions' Menu and the 'Options' Menu, and two additional buttons: a 'Hint' button letting the computer produce a suggestion, and an 'Undo' button allowing to take a piece back to its previous position.

Actions Menu¶

New game: Human vs computer

Starts a new game of xquarto, ending the previous one abruptly and letting the human start.

New game: Computer vs human

Identical to previous option, except that the computer will begin the next game.

New game: Human vs human

A new game is started with two human players, named as Player 1 and Player 2. The computer doesn't play any role, except for deciding which of the two players is the winner.

New game: Network game

Opens a popup from which you can specify a host to connect with, e.g. <othermachine>:0.0. You can then play with a human opponent working on <othermachine>, through the local network. The opponent must have set to export widgets to <othermachine> (just pass a phone call or an e-mail to tell him!). Again, the computer doesn't play any role, except for deciding which of the two players is the winner - and optionally managing mail between players or giving hints...

Save game

Saves the actual state game as .xquarto_save in the user's home directory.

Load game

Loads a previously saved game .xquarto_save from the user's home directory.

Help

Displays a short explanation of Quarto and Tic rules.

Quit

Exits from xquarto.

Options Menu¶

Quarto rules

Use quarto rules (who gets first an alignment wins).

Tic rules

Use tic rules (who is forced to realize an alignment loses).

Level trivial

The easiest level. The computer only tries to place the selected piece in a way that it does not lose immediately, and chooses any free piece to give away, i.e. it thinks only one move ahead.

Level easy

The computer thinks two moves ahead.

Level medium

The computer thinks three moves ahead.

Level hard

The computer thinks four moves ahead.

Level very hard

The computer thinks five moves ahead.

Level don't try

The computer thinks six moves ahead. This can be quite slow (and hard).

Game Type: normal

In addition to the rows and columns, the two main diagonals are dangerous (can make the game end).

Game Type: nodiags

Only the rows and columns are dangerous.

Game Type: torus

All 8 "diagonals" are dangerous. This corresponds to playing on a torus.

Undo Button¶

Cancels the last action made by human player(s).

BUGS¶

Probably plenty. Report any you find to mjo@math.kth.se

AUTHOR¶

Mattias Jonsson, Dept of Mathematics, Royal Institute of Technology, S-100 44 Stockholm, Sweden.

email: mjo@math.kth.se, URL: http://www.math.kth.se/~mjo