Oops, I did it again

I've been reviewing the rules for firing into melee, and true to form I screwed up the ruling.

There are two things that come into play: firing into melee, and cover.

When firing into a melee (which is defined, oddly enough, as any situation where two characters are in melee combat with one another and in adjacent squares), you take a -4 penalty to hit. This is standard, and is negated with the Precise Shot feat. Dead simple.

However, in addition, if you want to fire at a character through the square occupied by another character, then the blocking character provides your target with cover (unless there's a huge difference in size, but that comes up rarely enough to not matter). Anyway, cover provides a further -4 penalty to hit. Precise Shot does nothing to help with this penalty.

Furthermore, if your attack misses by 1-4 points (so, it would have hit if not for the cover), the missile instead hits the object providing the cover, in this case the other target. This has one of three effects. If the attack roll beats the covering character's armour class, then that character takes damage from the missile. If the attack roll doesn't beat the covering character's AC, but does beat his AC versus touch attacks, the missile hits the character's armour and bounces off, without causing damage. Finally, if the attack fails to beat the covering character's touch AC, then it turns out that that character didn't actually provide cover at all; the missile hits its intended target (personally, I don't like this last adjustment - I'd prefer that it either hits or misses the covering character, but there we go).

To illustrate this, let's consider two characters in melee combat, Alf and Bob. Let's imagine that Carl and Dave want to shoot Bob, but neither of them has Precise Shot. Imagine further that Dave has to shoot 'through' Alf to hit Bob, but that Carl does not.

Carl, therefore, takes a -4 penalty to hit Bob. He has no chance of hitting Alf. Dave, on the other hand, takes a -8 penalty to hit Bob. Worse, if he misses by 1-4, he hits Alf instead.

Imagine also that Eloi and Fraser want to shoot Alf. Both have Precise Shot. Fraser has to shoot 'through' Bob to hit Alf, but Eloi does not.

Eloi, therefore, takes no penalty to hit. He has no chance of hitting Bob. Fraser, however, takes a -4 penalty to hit Alf. If he misses by 1-4, he hits Alf instead.

And that's that. My mistake.