Hi folks, i gotta question.

Example: My ki ad has the quality "biocompatibility" that cyberware costs 10% less essence than it normally would. I gave him a lower cyberarm with essence cost of 0.45. With the quality that makes 0.405 essence. Is it that amount of essence or do you round it up to 0.41 or round it down to 0.4?

I've found nothing about it... so a quote from the rules would be great on that issue.

You don't round. If the character had 6 Essence before the cyberarm, they'd lose 0.405 Essence for the implant and now have 5.595 Essence.

Is there a rule for that? A quote from the books would be great.

There is no need to round up or down since a number can have an infinitly long decimal part. If you want to round anyway maybie because having 3 figure decimal part looks bad on the character sheet or whatever, just round mathematically so 0.405 -> 0.41, 0.404 -> 0.40 etc.

Unless there's a rule saying to round the value off, there's no reason to do so. Nobody can provide a page number for the absence of this rule.

So there is no rounding in SR4? In SR3 it essence loss was rounded to 2 numbers after the comma. Thanks for the answers.

There is no rounding concerning essence loss, AFAIS.

The language for magic loss and resonance loss says to round the essence down to the nearest whole number.
This makes me think Essence is left unrounded. There is nothing I've seen about 2 digits or other rounding conventions in SR4/SR4A.

Ok then what the hell do they mean with:

Augmentation - Entrance for Adapsin Geneware (dont know the exact page):

"... Adapsin reduces the Essence cost of implanting cyberware
(but not bioware) by 10% (round normally) if the subject has..."

The same thing is written in the german Bodytech (Page 97) - and as far as i know they implemented the errata in the german book.

I know it is the ONLY place where they say something about rounding in all rulebooks, but what should we do with it? Only round if someone has Adapsin - ignore it?

I'd go with just ignoring it. Absolute worst case scenario, the different things for changing essence costs for stuff will put you at 4 decimal places (including the halving of the lower of cyber and bioware). While situations where those last couple decimal places actually matter are going to be rare, between the ease with which I'd expect most players to be able to access a calculator, or a spreadsheet to calculate them - and how infrequently they'll actually need to be calculated.

I remember there was a rule to round to the second decimal place. IIRC it was in SR3 so it might not have made the jump to SR4. I don't have my books with me but I will try and remember to look it up when I get home.

That was SR3, M&M.