Help for the Game of Trichet

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

  trichet challenge [-num_tiles=n] [-win_size=n] userid1 userid2

Starts a new game for two players.

The -num_tiles option specifies the available number of tiles (default 96).
The -win_size option specifies the minimum number of tiles a region must have in order to win (default 10).


Trichet is a tile placement game of territory closure for two players.


Equipment: Two players, Oh and Dot, share a common pool of 96 triangular Trichet tiles. Each side of each tile has a 1/6 arc dividing the tile into two regions, marked 'o' and '.'.

       +            +
      ooo          /.\
     ooooo        /...\
    /.....\      ooooooo
   +-------+    +ooooooo+

     Front         Back

Start: Oh starts by placing two tiles in the middle of the playing area as shown:


Play: Players then take turns adding a tile of their choice to touch at least one edge or corner of an existing tile such that all neighbouring regions match in colour.

Auto Moves: Each move may result in one or more positions at which only one tile in one rotation may be placed such that colours match; all such positions are automatically made as part of the the move. Each auto move may result in additional auto moves, hence each player move will usually result in multiple tile placements.

For example, the move shown below creates two positions p and q (left) which only have one valid placement each, which are automatically made (centre). Placement p then creates position r which has only one valid placement, which is also automatically made to complete the move (right).

                                          r                            /...\
       +       +                      +ooooooo+ooo----+              +ooooooo+ooo----+              
      ooo  p  ooo  q                 ooooooooooooo.../              ooooooooooooo.../             
     ooooo   /.ooo                  ooooo.../.ooooo./              ooooo.../.ooooo./              
    /.....\ /                /.....\./              /.....\./...ooooo           
   +-------+----ooo+     --->     +-------+----ooo+     --->     +-------+----ooo+ 
    \...../                        \...../                        \...../                   
     ooooo                          ooooo                          ooooo                    
      ooo                            ooo                            ooo                      
       +                              +                              +                     

Aim: A player wins by completing surrounding a region of their colour that uses at least 10 tiles (i.e. a circle of 6 arcs is not sufficient). For example, Dot wins the following game:


If a move surrounds regions of both colours then the mover loses. If the tiles run out before either player encloses a region then the game is tied.


The default number of tiles is 96 as this number allows all tiles to be placed within a hexagonal shape according to the formula f(n) = 6*n*n.


The following command plays tile rotation 'd' at position 3, in addition to any resulting auto moves:

  trichet move <game#> <userid> <passwd> d3           


Trichet tiles and rules by Cameron Browne and copyright © Cyberite Ltd 2008.

The name “Trichet” refers to the game's origins as a form of triangular Truchet-like tiles.

Graphical web interface:

More details are available at the official Trichet page.

Implementation and Help file by Cameron Browne, December 2008.