Who rolls first?
The old U.K. rules are quite clear that the attacker rolls the dice first, then the defender rolls. Though it isn’t explicit, this suggests that the defender can choose how many to roll based on the attacker’s dice, since this would seem to be the only point of rolling later. This sometimes causes the defender to use only 1 die when he was entitled to use 2. If faced by 2 sixes you only roll 1, whereas faced with the second highest being a one you roll 2. (In both cases this assumes you are not trying to let the attacker through with minimal losses to get to a mutual enemy.) The U.S. and new U.K. rules specify that both attacker and defender decide beforehand and roll simultaneously. This leads to a faster game and it is rare that the defender rolls 1 when entitled to 2.