     XTIC(1)                    Mattias Jonsson, KTH                     XTIC(1)
                                         X11

     NAME
          xtic - 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 pieces. The
          player who places the fatal piece loses.

          The game is a two-player game, although in the current release, only
          the human-computer combination is supported.  Player 1 (the human by
          default) chooses one of the 16 pieces. Player 2 (the computer by
          default) 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.

          As mentioned above, the game is over when a player places a piece in
          such a way that a row, a column or a diagonal (but see below) contains
          four pieces carrying a common property.  The player who places this
          piece loses. If there is no empty square left, we have a draw (yes,
          this can happen).

     MENU COMMANDS
          There are two menus, the Actions Menu and the Options Menu.

     Actions Menu
          New game - You start
                  Starts a new game of xtic, ending the previous one abruptly
                  and letting the human start.

          New game - I start
                  Identical to "New game - You start" except that the computer

                                        - 1 -       Formatted:  December 3, 1999

     XTIC(1)                    Mattias Jonsson, KTH                     XTIC(1)
                                         X11

                  will begin the next game.

          Quit    Exist from xtic.

     Options Menu
          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.

     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

                                        - 2 -       Formatted:  December 3, 1999