How do % increases stack?

[risikawi]

When you get promotion or building or whatever that increases something by X% and you allready have something boosting the same thing by Y% there are two ways how these could stack - either by multiplication or by adding them up and then applying to base value - now which way it is in civ ?

Just to give example why it matters - say there is a unit with combat 100 and all three drill promotions:
100x(20+20+25)=165
100x20x20x25=180

So with multiplication the actual inrease is 80% not 65%, meaning that with units, at least, it would make choosing next level of same promotion more favourable than taking diffrent promotion

 

[aimlessgun]

I think it's always additively. You can check in the game though I suppose, just do some math. Not sure if there are any bonuses that are exceptions.

 

[Slowpoke]

It's definately additive for combat.

 

[jorissimo]

100x(20+20+25)=165
100x20x20x25=180

You meant 100x(1+0,20+0,20+0,25)=165, right?

 

[Zechnophobe]

You meant 100x(1+0,20+0,20+0,25)=165, right?

I love the global community of the internet. But man, every symbol set that has ',' and '.' swapped freaks me out. That looks a whole lot like 1+0; 20+0; 20+0; 25. Which makes absolutely no sense.

 

[eric_]

lol Zechno, I had the same initial reaction!

 

[Lanstro]

And some of them just work funny. One game I had Big Ben (25% cheaper to buy things) and the Mercantilism social policy (-25%). Things were costing me half price to purchase - all fine and dandy.

Then I got Militarism from the autocracy tree (-33% cost of buying units), expecting units to suddenly cost only 17% of original. Nope, they cost some funny amount that was just under half price, which I suspect was 42% (so one of the 25% reductions from Big Ben or Mercantalism was ignored). Which was a pity - 17% cost purchasing of units would've made for a total steamroll!

 

[milk steak]

^ There might be a hard cap as to how low you can reduce things.

 

[UknowsI]

But in some situations this will have an advantage too. I believe the open land penalty and the promotions also stack additively, which makes it quite possible to defend on flat land with a double or triple shock promotion.

 

[Rathelon]

I love the global community of the internet. But man, every symbol set that has ',' and '.' swapped freaks me out. That looks a whole lot like 1+0; 20+0; 20+0; 25. Which makes absolutely no sense.

That's how them Europeeeans do decimals, right?

 

[risikawi]

You meant 100x(1+0,20+0,20+0,25)=165, right?

No, I meant what I wrote, what is the diffrence, if we got same result ?

And people from English-speaking parts doing every thing the other way around and complaining that everyone else is doing it...

I am not really spreadsheet kind of type, I just got curious. Non-unit bonus multiplication might be harder to implement as they often don't come in any particular order, hovewer military do and if they multiplied it would be usefull to know - I often chose both drill and shock as free promotions from buildings in city making unit more versatile, but it may be more sensible to specialise it, if you got much more combat strenght from it.

 

[Soronery]

100x(20+20+25)=<-----this is the problem 165
100x20x20x25=<--- this is the problem 180

Why is it a problem?
100(20+20+25)=650
100(20)(20)(25)=1 000 000

To correct what you wrote:
100x(20+20+25)&#8800;165
100x20x20x25&#8800;180

 

[Slowpoke]

^ There might be a hard cap as to how low you can reduce things.

There is, it's 75% reduction as far as I can tell from the xmls. Which is quite a lot O.O

 

[jorissimo]

No, I meant what I wrote, what is the diffrence, if we got same result ?

And people from English-speaking parts doing every thing the other way around and complaining that everyone else is doing it...

I am not really spreadsheet kind of type, I just got curious. Non-unit bonus multiplication might be harder to implement as they often don't come in any particular order, hovewer military do and if they multiplied it would be usefull to know - I often chose both drill and shock as free promotions from buildings in city making unit more versatile, but it may be more sensible to specialise it, if you got much more combat strenght from it.

We didn't get the same result...
100(20+20+250)=6500=rediculous?
100(1+0,20+0,20+0,25)=165
Oh, and about the commas, that's where Americans would use '.'

 

[Seanirl]

I've a question about the comma system...

What if you wanted to express one hundred thousand one hundred and twenty five, but also one hundred point one two five?

Wouldn't they both be 100,125?

Have I discovered a fatal flaw in this system?
Probably not, but I'm still curious.

 

[humbe]

I've a question about the comma system...

What if you wanted to express one hundred thousand one hundred and twenty five, but also one hundred point one two five?

Wouldn't they both be 100,125?

Have I discovered a fatal flaw in this system?
Probably not, but I'm still curious.

Tsk.. Americans .. Where comma is used to separate the integer part from the rest, dot is used to separate thousands, and vice versa. I've never liked the thousand separations anyways though.

So that would be 100,125 and 100125 or 100.125 if you really wanted the thousand separation. Many applications I see rather put in a space in between rather than dot for thousand separation though.

As to the original posters question, it varies depending on what mechanism you're talking about.. Some are additive and some are multiplicative. Though I think most are additive. The bonuses come in different shapes and sizes too. Some don't specify percent increase. For instance the library that gives +1 science for every 2 persons. That's +50% to research to the base population research, but that's a multiplicative bonus added before the other bonuses which in this case is additive.

Also, it would be great if the game actually gave formulas, as this is crucial information to know what effects gives good synergi and which doesn't. Takes a lot of time to figure everything out by trying.
Tried to find out how number of city unhappiness was calculated last night, but failed.. The numbers just didn't add up any way that made sense to me.

(Huge map = - 40%, indians +100%, but the formula wasn't "number of cities * 2 * 0.6 * 2", neither was it "number of cities * 2 * (1.0 + 1.0 - 0.4)")

The economy screen actually showed all the bonuses/penalties I had which was great. The description just didn't add up to a formula that calculated the correct result.

 

[risikawi]

I assumed I am using % to manipulate 100, since that is what the thread about I assumed you`d know what I mean

I've a question about the comma system...

What if you wanted to express one hundred thousand one hundred and twenty five, but also one hundred point one two five?

Wouldn't they both be 100,125?

Have I discovered a fatal flaw in this system?
Probably not, but I'm still curious.

No, because we don`t use comma as thousands separator, that is the fatal flaw of you having to be different from others - people think that you don`t either so it seems that your numbers are terribly small

 

[Seanirl]

Tsk.. Americans ..

I'm not American

Where comma is used to separate the integer part from the rest, dot is used to separate thousands, and vice versa. I've never liked the thousand separations anyways though.

So that would be 100,125 and 100125 or 100.125 if you really wanted the thousand separation. Many applications I see rather put in a space in between rather than dot for thousand separation though.

I've never noticed that before. I'm familiar with the whole 1,24 and whatnot system from seeing it in currencies and stuff but I don't remember ever noticing a . for thousands.

Hmmm... this article is actually quite interesting:
http://en.wikipedia.org/wiki/Decimal_mark

Says the French started using the comma because they used a . for Roman numerals... whereas Islamic mathematicians before then used a small vertical stroke, kind of like halfway between a comma and a dot.

East Asian countries use a dot as well... and computers use the . system in programming languages and such so it must be best

 

[jorissimo]

That more people use it, doesn't mean it's the best. These are just two systems, there isn't a 'better' system, they are just different. People use the one that they're brought up with. It's kinda silly to make this into a comma versus point war or something.

 

[Wurlf]

-love the debate on ',' and '.' as I'm a ',' person living in a '.' country...-

anyway, regarding the % questions, I find the info-scroll thingy in the game quite informative.

Always give you the detail of calculation before the fight and if yu mouse overany number in city screen (food, hammer, bulbs, gold and culture especially) you'll find the details of how these are calculated including any buildings and wonders involved and in which order.

That's how I found out the the bonus for food when you provide a luxury good wanted is applied 'after' the population's feeding. (not related to the current topic but illustrate well my point).

same way there is quite some info within the economy menu if you find your way there (that little scroll left to the three big buttons at the top is actually quite useful).