Ringworlds and Sphereworlds

[Suicide Junkie]

While there are 169 potential places for the random movement to pull you towards, the ones near the center are MUCH more likely.

If you are not in the middle, then there is a greater chance to be pulled in the general direction of the center than away, since there are more squares on that side for the pull direction to choose from. (You are pulled towards a random square, not really random directions)
The pull square dosen't even have to be the center, since if you are 2 squares left of center (and up or down at most 2) and the pull (strength 2) is in any of the squares right of the center, you win also.