I'm building a chemist who is a bit of a pyromaniac and have spent some time memorizing the explosives sections in both SR4 and Arsenal and have a question.

On SR4 p.315 it says "When attached directly to a target, the target's armor value is halved, otherwise the explosive is assumed to have an AP value of 0."
In the advanced demolition section of Arsenal it never mentions this rule at all, even in the multiple examples for calculating charge size for breaching walls and such. It isn't mentioned in the SR4 Errata either, so what gives? Am I to assume that this rule has been tossed in favor of the charge positioning DV multipliers on Arsenal p.90?

anything in Arsenal that is different from the core rulebook has been ADDED for advanced gameplay.

So.... they are meant to be used even if they were specifically omitted from the breaching examples of a later published book, which is about the only place they really apply? Do these advanced rules replace the simple ones?

Sorry if I'm being dense, intentionally or otherwise, but what you said doesn't really answer my question.

I think he means that you use either the simplified rule in the BBB or the advanced rules in Arsenal.

Word on this from the developers is that new rules in SR4 supplements never intentionally contradict the BBB. If a BBB rule isn't used in an example in a supplement you can presume that it is an unintentional omission.

In other words, use both. Always use both unless the new rule is explicitly stated to be an optional rule that replaces an old rule if used.

Thanks, thats exactly what I needed. I really didn't care either way, just wanted to know the official ruling.