Rules Interactions

This is Steven Petrick posting.

One of the hard parts of a large game is trying to incorporate the interactions of different rules. This problem, however, can even pop up in a relatively small and simple game, such as Space Hulk.

The Space Marines include one man equipped with a shield. This shield has the effect of allowing the Space Marine player to cancel the highest die roll made by a given genestealer in hand-to-hand combat with that Marine. That sounds simple, but what happens if that Marine faces off with the brood lord?

The brood lord is allowed to combine his two highest dice into a single roll.

So, assuming the brood lord is attempting to kill the Space Marine with the shield do you:

A.) Have the brood lord throw his three dice, say a 2, a 4, and a 6, and the Space Marine's shield cancels the 6 resulting in the brood lord scoring 6 points of damage by combining the two remaining dice, or

B.) Have the brood lord throw his three dice, say a 2, a 4, and a 6, combine the 4 and the 6 into a ten and then the Space Marine's shield cancels both of them (since they have been combined into one mighty blow and thus are a "single die") and so the brood lord scores only 2 points, or

C.)Have the brood lord throw his three dice, say a 2, a 4, and a 6, and the Space Marine's shield cancels the 6 resulting in the brood lord scoring only 4 points of damage because the 4 would have been combined with the 6 and the 2 would have been ignored normally.

The interaction between these two rules is simply not explained, allowing the rules lawyers to have a field day, and resulting in different groups getting radically different results depending on what "local ruling" prevailed.

I wish I could say that SFB is free of such problems. I do try to make it so (any new rule starts with a review of the table of contents and the question "how would this affect that?"), but I am sadly not perfect.
We do try.