This has become a tricky question. I'm making a test-bed character with augmentations in all flavors - Cyber, Bio, Gene, and Nano - and with all of the good Essence reducers - all Delta because what the hell, has the Biocompatability (Cyberware) quality, and is going to have Adapsin gene therapy.

In terms of base costs, the math as I have it working out now would be 5.65 Essence worth of cybernetic augmentations. Now, here's my question, what's the order of operations?

Do I add up the (not-yet-listed) Bioware first, and compare it to the Cyber, reducing the lesser of the two by half? Or does that step come last? I think it comes last, by my present understanding.

Now, with 5.65 essence worth of cyber (so far, haven't gotten around to any nanoware yet,) how do I reduce that?

Do I reduce it to 30%? (50% discount from Delta grade, 10% discount from Biocompatability, 10% discount from Adapsin?) Do I reduce it to 50%, reduce that number by 10%, and then reduce that number by 10%? Do I reduce it by 50% (grade) and then add Biocompatability and Adapsin together and reduce the 50% number by 20%?

The answers are not the same, not at all.

5.65 * .5 is a healthy 2.825.
2.825 * .8 is an even healthier 2.26
2.825 *9 is 2.5425, and 2.5425 *.9 is 2.28825
Whereas 5.65 * .3 is an astoundingly low 1.695.




Was this enumerated somewhere and I simply didn't notice?

There are actually two answers to this question.

The multiplication math depends on whether you're using the german patch or not. You're supposed to multiply the essence costs by all the discounts.
That is to say, if you have two 10% discounts on a basic grade cybertorso you muliply 1.5 x .9 x .9 and get 1.215.
Using this system, you get the Secondhand Alphaware exploit that's cheaper and costs slightly less essence (.96) than buying regular grade.

I believe the german patch(and unreleased arsenal augmentation) changed the essence calculations to use Lazy Math. That is, you add up all the bonuses once then multiple. two 10% bonuses and alpha ware for 20% gets added up to 40% total.
Its way easier to do, and needs less of a calculator and/or tons of pasting into google, and fixes the secondhand alphaware exploit(+20%-20%=0% change), and tends to make more whole numbers, but takes sliiightly more essence than the other method.

So you need to figure out which method of essence calculations you're using first.

Once you do that, its easy:
Cyber and Nanocryber count as Cyber, so you total all those.
Bio and Gene count as gene, so you total all those too.
the lesser category gets half off per the usual rules.

So, Delta + Adapsin + Biocompatability means you get cyberware at a whopping 30% of what its normal Essence cost would be, using the Lazy Math?

yes, and x 0.405 using Real Math.

It only takes more essence cost for the additive method when you include penalties. If you're only getting essence cost bonuses then the additive method comes out ahead of the multiplicative method.

Used Alpha costs the same money-wise


Only for the Essence cost modifier of cyber suites. Everything else, including ¥ cost of suites, remains the same.

Doesn't change the fact that it cost less essence if you don't add the modifiers together first.

Then where did the Lazy Math Method get introduced? Was that a missions thing?

It's what multiple author said to be in the never relised Augmentation errata and is also inferred by multiple people as a way to go based on the only % modifiers in the game that actually have rules about how they stack(the modifiers to initiation/submersion cost)

Plus most of the examples used lazy math if you worked them out. It ends up being way less headache and you're talking about a system that was intended to be more streamlined, after all.

Okay, that's what I thought.

You know the german version includes the unreleased errata, right?

I read a post over on pegasus that, basically, they send all their corrections and improvements to CGL for approval as they print stuff- and have actually got the missing errata files. I've seen people quoting from it occasionally, I believe the current version was 1.31 or 1.32.

And CGL just goes "okay!" and lets it sit in an inbox somewhere instead of actually doing their job and letting their english-speaking customers share the goodies.
No fragging respect for the consumer at all.

for Me its definitely the "lazy Math" version because its exactly like this in my German Books

....and what Udoshi says
(its exactly that way)

with a lazy Dance
Medicineman

The lazy version works, if you exclude cybersuits. So a cybersuit counts as "one piece of ware" with the allready calcuated costs..

It would become a problem, if there were more ways to reduce the essence costs...

Or to but it like that:
30% or 40% of the costs aint't a big differance....
But 10% or 30% would definitly be one.

It only gets a big differance if you get to the lower end.

In general this lazy math methode always runs into problems, if the amount of modifiers is not limited.

Same issue with the normal math solution and positiv modifiers.
10 times +10% would be 100% or ´+150%.
Probably best known for spelldurations: Double the spell duration for a malus of X. Works quite good as long as you only can do it 2 or 3 times....

I know that's wrong, because I know cybersuites were addressed SEPERATELY to fix the math error that was made in their construction of base stats.
Here, I think sengir's responsible for translating some of the stuff from the german books: http://pdfcast.org/pdf/germanstuff Page 6, sidebar. Sadly, it doesn't include all the changes, just the extra toys.



Speaking of which, Medicineman, can I ask you to look something up for me, please? If you have a minute to look at your books.

Can you tell me if your german Nanobiomonitor actually has a game effect now, and what it is?
I'd also like to know what the Max Rating is on Dynamic Handprints, Retinal Adjusters, and Voice Mimics - should be on page 113. I've heard it was 9 and I want to confirm that before I use it.

Nanovitalmonitor Page 118 Bodytech:
.....in combination with Nanosymbiontes,O-Cells and other medical nanites....raises the effective level of Nanosystems by +1

Dynamic Handprints Level 1-9 Avail 12V
Retinal Adjusters Lvl 1-9 Avail 16V
Voice Mimics Lvl 1-9 Avail 16V
Jouh thats correct

with an affirmative Dance
Medicineman

P.S
we could've used PMs for that....

But now everyone knows this information! Data rules the universe!

But really, the lazy math method actually allows you to avoid more trouble and headache. You don't run into things like

"Do I subratct the 20% from Beta before or after the adapsin, biocompatabilty, and suite option?" (or whatever the percentage is, brain not working right now). Instead, there is no order of operations to consider, it merely becomes 100(%) - (20+10+10+10(%)). And even with every modifier available to you, you cannot hit full essence reduction.

I was always taught that unless specifically called out, you lump like terms with like terms then combine them with everything else. It's all about the order of operations in mathematics.

Thus the way I have always treated Essence mods is what everyone is calling 'lazy math'. It's hardly lazy and it has always come out ahead of fully multiplicative combination.

BTW, additive modifiers that were combined first and then multiplied against the base value is how the previous versions handled it. I see no reason why SR4/A would treat it differently absent a specific rule change (which I might add doesn't exist).

ESSENCE_COST * (1 - SUM_ALL_ESSENCE_MODS) = DISCOUNTED_ESSENCE_COST

Lazy math avoids exponential growth and exponential growth usually means migraines in RPGs due to runaway power. Such as four 100% increases to spell duration meaning a 1 minute duration becomes 5 minutes under the additive method vs 16 minutes under the multiplicative.

I find 'Lazy Math' to be a misnomer though since there is a term that references those operations.

Thanks, medicineman! I didn't even think of PM's, sorry.

Darthmod: Do people not teach PEMDAS these days?

1 - (1 * 10 / 100) - (1 * 10 / 100) - (1 * 20 / 100) + (1 * 20 / 100)

1 * (1 + 10 / 100) * ( 1 + 10 / 100) * (1 + 20 / 100) * (1 - 20 / 100)

PEMDAS isn't the problem.

Well, unless you are dealing with reduction. Then it is the other way around. A reduction of 99 reductions of 1% or not that great, unless you add them together....

Er. Exponential growth. The additive method is linear in reductions. The multiplicative method is still exponential with reductions. You're just heading left on the curve towards zero rather than right with each additional reduction provide a smaller overall change that one previous.

It's also easier to install floors to combat the additive method over installing ceilings to combat the multiplicative method.

I dunno, man, you're still doing addition before multiplication. If you're adding together the multipliers before multiplying them, you're breaking the order of operations.

If games want to have extra-fancy not-breaking-the-rules math they need to make that clear in the rule book. The Cancer Game's special rules for critical damage multipliers stacking up is a prime example of additive multiplication(a doubled double is a triple) instead of real multiplication.(it would be four times)


All in all, I feel that adding the discounts up first saves a ton of math hastle, though it is super dumb this wasn't clarified officially and set in stone near launch. For such a core mechanic, so many years after launch, its wonderful that people still can't figure out how to calculate things right.

The P in PEMDAS means you resolve the inside of a parenthesis to generate a value. That can and will result in addition being done before multiplication.

(4 + 3 * 9)^2 means you resolve the 4 + 3 * 9 first according to PEMDAS. Which means you do the 3 * 9 = 27 then add 4 then apply the square for 961. The top method that I wrote is the longhand for the additive method. You don't actually do any addition before multiplication with that method. The bottom one is the multiplicative method which has the addition before multiplication.

1 - (1 * 10 / 100) - (1 * 10 / 100) - (1 * 20 / 100) + (1 * 20 / 100)
1 - (10 / 100) - (10 / 100) - (20 / 200) + (20 / 100)
1 - (0.1) - (0.1) - (0.2) + (0.2)
1 - 0.1 - 0.1 - 0.2 + 0.2
0.9 - 0.1 - 0.2 + 0.2
0.8 - 0.2 + 0.2
0.6 + 0.2
0.8

1 * (1 - 10 / 100) * ( 1 - 10 / 100) * (1 - 20 / 100) * (1 + 20 / 100)
1 * (1 - 0.1) * (1 - 0.1) * (1 - 0.2) * (1 + 0.
1 * (0.9) * (0.9) * (0. * (1.2)
1 * 0.9 * 0.9 * 0.8 * 1.2
0.9 * 0.9 * 0.8 * 1.2
0.81 * 0.8 * 1.2
0.648 * 1.2
0.7776




The additive method I believe is call summing the percentages or something like that. 50% of base + 50% of base + 50% of base. This is an entirely legitimate method of doing things.

It fairly easy to see how it was included in the original SR4 book. There were only two things that affected essence cost and that was 'ware grade and the Sensitive System negative quality, but it says to double the loss so it probably is supposed to be applied at the very end since it is a doubling and a not a 100% increase. The addition of biocompatibility, adaptsin, and secondhand 'ware is where it was broken since that is where stacking of essence cost modifiers should have been addressed.

It takes quite some time for the "exponetial" thing gets out of hand.
For example: If you increase the damage 9 times by 10% you end up with 235% instead of 190%. Thats just under 25% off.
If you reduce cost by 9 times 10% you end up with 35% instead of 10%. Thats 300% off.

So I have to disaggree here. Mostly because there is nearly always an upper limit you can go to (your dicepool, your skill etc.)