It is one of the problems of IGo UGo games, can the other player just storm across the board and crash into the enemy, whilst the enemy sits there and does nothing? It is this aspect of the games that has put some of the local players off these type of games.
On the other hand it seems that the really short range fire (from muskets) was the thing that counted - and that is covered in Black Powder.
One rule mod might be to allow the non-phasing player to shoot each time the enemy makes a move within their shooting range? That way units cannot just leap forward unscathed across ground.


