Copyright (c) 2001 Don Green

THE SNAILS - A snail moves to any adjacent (orthogonal or diagonal) occupied cell, capturing the token (and thus, no snail can move to that cell again).
One the first turn, White move one cell. Then, Black moves 2 cells, White moves 3 cells, ...
GOAL - A player unable to move looses the game.

An example

White just moved 6 cells. If Black makes the following sequence of moves (the marked violet stones), he traps the White snail: He must move 8 times, but only has 5 cells left.

There is a ZRF to play Snailtrail with Zillions. Check Slimetrail for a similar game