I meant to include a table with the probabilities at each level, but I'm not sure my math is right. Probabilities when rolling two dice is much more complicated than when rolling one. I'm sure I could do it, it's just not worth the headache right now.

I'll explain it a different way. Imagine the game has started, and players are about to take the first turn. Before anything else (unless the wave moves AFTER everyone else has, but bear with me here) two dice are rolled. The wave is currently parked on system 1, ready to move to system 2. In order to move, the roll of two dice must be GREATER THAN the next space the wave will reach, which is 3 or higher. Unless you roll two ones, the wave WILL move forward. In fact, it is not improbable that it will continue to move on unimpeded up until it reaches the 5th system. At this point you will need to roll at least a 6 for the wave to continue, otherwise it stays put this turn. So you continue to roll and the wave continues to move forward less and less frequently until it finally dies on system 12. There is no way to roll a 13 with two dice, so presumably the game ends here with the player who scored the most VP winning the game.

I don't quite understand this...could you give me more details on what you're trying to describe?