Slimetrail, a slithering slug strategy game

This rendition of the rules is by Dave Boll.

Game by Bill Taylor.

Rules

Slimetrail is a two player, abstract conflict game played on an NxM rectangle of squares. Each player takes turns moving a piece around the board. The piece can take one step orthogonally, and may not re-visit a visited square. Each player tries to move the piece into his/her goal square. The two goal squares are located at diagonally opposite corners of the rectangle. The piece starts on any mutually agreed upon square.

Note: It doesn't matter which player actually ends up moving the piece into a goal square; just the fact that it is there means that someone won.

Analysis

A first player win exists, starting from any square, provided at least one of the board dimensions is even. On an odd by odd board, winning and losing start squares alternate in a checkerboard pattern. A draw is only possible via cooperation; if one player moves to avoid draws, the other can never force them. We're still wondering if the winning/losing start square pattern means there is an easy strategy for this game that neither of us has seen yet.

Variations

Chess king slime trail: The piece moved around the board has the movement capabilities of a chess king. Results for small boards (1st player goes to upper left, 2nd to lower right)

      W = Winning start square for 1st player, assuming perfect play.
      L = Losing start square for 1st player
      T = Tied game with perfect play. (A game is tied if neither player
      has a move)

       3x3       4x3       4x4         4x5           3x5
      * W L    * W W L    * W L W    * W W W    * W W W L
      W W W    W W W W    W W W L    W W W W    W W W W W
      L W *    L W W *    L W W W    W W W W    L W W W *
               W L W *    W W W W
                          W W W *

(the additional movement capabilities makes deep search difficult) Seems to be biased toward the 1st player, with losses only cccuring (sometimes) in the vincinity of the non-goal corners. It should be noted that some of the start squares marked W have only one winning move out of the eight available, and the direction of that winning move is not obvious at all - so they still make for fairly good games.

Hex slime trail, targets in obtuse corner. Probably the best version of this game. Here's some small board results:

        4x4        5x5          5x4          4x6
        * W T L    * W T W T    * W T W T    * W T L
       W W L T    W W W W W    W W W W W    W W L T
      T L W W    T W W W T    W W W W W    T L W W
     L T W *    W W W W W    W T T W *    W W L T
              T W T W *                  T L W W
                                        L T W *

I think this variation is best because of relative balance of start squares that lead to W, L, or T. We really haven't playtested this one enough to vouch for superior play-ability.

Hex slime trail, targets in acute corner. On 4x4 and 4x5 board all squares win for first player. Draws are too easy to come by in this version.

      5x5
      * W T T T
       W L T T T
        T T L T T
         T T T L W
          T T T W *

Rules write up by Dave Boll, Colorado, USA

boll@CS.ColoState.EDU
Jan 18, 1993

The Game Cabinet - editor@gamecabinet.com - Ken Tidwell