Okay, say that we have a street samurai with 1.3 essence and a moderate wound. Our mage with Sorcery 6, and a full spell pool and health, and no bioware/cyberware, goes to heal him with a Level 4 Heal spell. How is drain calculated, exactly? It's Force Level or Force Level divided by 2, times the wound level, right?

Also, if you roll well enough, can you avoid drain entirely? Do you do a separate roll to see if you avoid drain? I've got the SR3 core rulebook in front of me, but I'm scratching my head. The combat rules for weapons are so much simpler...

Nevermind, I figured it out. Silly me. Except for one small problem...

How does essence enter into this equation?

Low essence increases the target number of the Sorcery test. The target number is, I believe, 10-essence.

Okay, I've got it now. How about Bioware? I don't see it in the equation, but I thought it also affects Heal spells.

You also add half of the Bio-Index to the TN.

Ah, thank you very much.

Yeah. No problem. Sadly, your samurai probably isn't going to get that heal spell any time soon, though.

So if you have 1.3 essence, you have a TN of 9 (or does it round down to 8?). Except if you factor in the 2.4 points worth of bioware, the TN goes up by 1.2. So basically its a target number of 9.9 (which either rounds up to 10 or down to 9).

I think that you end up with an 11, since you get a 9 out from the essence, and then add 1.2, which I believe you round up to two.

From what I remember (it's been a while), you add the two before calculating anything. So 4.7 Essence + 1.2 Bio-Index (half of 2.4) = 5.9. I believe that this would result in a target number of 9 though, because (also from memory) you round down to whole numbers in this case.

As I remembered it, you always round to your disadvantage.

No books, so can't back anything up. I do know that there were exceptions to that general rule though, and I believe the wording in this case is one such exception. If not though, then the TN would be 10.