Skill/ship bonus are applied as a total %
Module/rig bonus are applied each as a % of the remaining stats after the last bonus applied.
I'm not so sure that makes sense. I need more coffee

See this for a more detailed explanation of how stacking works: Eve Uni to the Rescue

PS: there is no need to mention diminishing returns, I am aware of that.

So skills and ship bonuses that affect a variable are accumulated and then applied? so x*1,55 for the example above?
Makes perfect sense, could you tell me where I could verify that? (Where did you found that info)
I dont really get what you mean with module/rig bonuses, could you clarify that for me please?

everything in eve stacks multiplicatively and most of the time are subject to stacking penalties apart from a few notable exceptions (damage control and reactive armour hardener).

everything in eve stacks multiplicatively

An EANM gives you 20% resistance across the board. An energized em membrane then givea you 35.7%. That 35.7% is taken from the remaining 80%, not the original 100% so...diminishing returns.

resistances are added together, so are flat boni to cpu, cap etc.

resistances are added together, so are flat boni to cpu, cap etc.

OK. But that's only the case for resistances, right?

___

Here's the deal guys: In a Bellicose fitting, with Min Cruiser V and Signature Focusing V, you get a 37,5% and a 25% bonus to Target Painting. Now, is the formula either A: 30*1,625 or B: (30*1,375)*1,25? (or, in the case of a specific order to bonuses being applied, even a option C: (30*1,25)*1,375?

I'm also interested how it would work for other variables.

Bonus Multiplier = (1 + bonus1) * (1 + bonus2) * (1 + bonus3) * ... * (1 + bonusN)

Stacking penalty applies to some modules with the same effect. The effects are sorted from largest to smallest before applying penalties.

Aenigma's Stacking Penalty Guide

Number of modules/rigs Stacking penalty
1 1.000000000000
2 0.869119980800
3 0.570583143511
4 0.282955154023
5 0.105992649743
6 0.029991166533
7 0.006410183118
8 0.001034920483
9 0.000126212683
10 0.000011626754
11 0.000000809046

Bonus Multiplier = (1 + bonus1 * 1.0) * (1 + bonus2 * 0.869119980800) * (1 + bonus3 * 0.570583143511)

There is no order, because you multiply all factors together, there is no addition.

um, no theyre not?

And please don't ever write "boni" again, it's not a word.

Thanks everybody for replying in my topic to help me but for God's sake, read the original post thoroughly and then reply. I am (specifically) not asking about diminishing returns nor am I asking something about resistances in specific.

yes they are, otherwise T1 ships would not be able to get EM shield resistance.
depends on the language.

One really cannot discuss resistance bonuses without mentioning stacking penalties.

Resistances are affected by resistance modules, resistance rigs, and damage controls. Damage controls are not stacking penalized, but the rest are.

Note that ship resistance bonuses are not stacking penalized either. [Neither are implants, nor skill bonuses when applicable.]

If there is a stacking penalty, the ring or module will indicate so.

So you are saying is, all modifiers are added together and then applied to the variable? (30*1,625)?
Where did you found that information?

Things generally work multiplicatively:

Example:
For T2 Nuetron Blaster Damage on a Thorax:
Total Damage =
Base Damage Modifier (=4.41 for a Nuetron Blaster) *
( 1 + .05 * Gallente Cruiser Level) * |
( 1 + .05 * Med Hyb Turret Level) * | Skills don't have Stacking Penalties
( 1 + .02 * Med Blaster Spec Level) * |
( 1 + .03 * Surgical Strike Level) * |
( 1 + .10 for the first t2 Magnetic Field stabilizer) *
( 1 + .10 for the second T2 MFS * 0.869 <- stacking Penaltiy for second module altering the same attribute) *
( 1 + .10 for the thrid T2 MFS * 0.571 <- Stacking Penalty for the third module altering the same attribute) *
( 1 + .10 for the Hybrid Collision Accelerator Rig * 0.283 <- Stacking Penalty for the fourth Module alter the same attribute)

= 11.328 at all level 5's

Why, good sir, are you discussing resistance bonuses in my topic about modifiers in general and the order (or not) in which they are applied?

You know what, nevermind. I'll head to BattleClinic

Example:

Shield Thermal Resist on a Drake with 2x IFs, 1 anti-Therm Shield Rig, and a DCU.
Base Thermal resist on a Drake's Shields (20%): Don't look at this as a 20% increase in resists, look at this as it receives only 80% of the incoming damage!

It is best to look at this as damage it receives. Starting with 1:
1 * ( .8 From Base resists ) *
( 1 - .04 * Caldari Battlecruiser Skill Level) *
( 1 - .125 from Damage Control II <-- special module that does not stack) *
( 1 - .30 from the First Invulnerability Field II ) *
( 1 - .30 From the 2nd IF * 0.87 <- Stacking Penalty for second Module) *
( 1 - .30 From the Anti-Therm Rig * .57 <- Stacking Penalty for the third Module)

= 0.240
If you were to receive 100 damage incoming, only 24 damage would be inflicted to your shield HP.
Your Shield resistances would be 1 - 0.240 = .76 = 76%

Thanks for your answer. Could you explain to me how I apply this into the field of Ewar? So how do I calculate bonuses for target painting? Target painters dont have base modifiers, afaik.

resistances, ignoring stacking penalties:

Resistance 1: 30%
Resistance 2: 25%

Resistances are applied to incoming damage. So, 100 damage coming in.

100 * (1-0.3) * (1-0.25)

or 52.5 damage remaining. resistance of 47.5%

Modules that increase your ships Resistances do NOT ignore stacking penalties... That's simply incorrect.

Ok, The increase in sig radius of your target, from a Huggin with 3x T2 Target Painters, assuming all level 5 skills:

The signature Radius Bonus of each module should be calculated first:
Sig boost from a single t2 Paint = +30% (Base module value) *
( 1 + .05 * Signature Focusing Skill Level ) *
( 1 + .10 * Minmatar Cruiser Skill Level )
== +56.25% per painter with all level V Skills

So, a Frigate with a 40 m Signature will have
40 (no Paints)
40 * ( 1 + 0.5625 ) = 62.5 m (1 Paint)
40 * ( 1 + 0.5625 ) * ( 1 + 0.5625 * .87 <-- Stacking Penalty for Second Module) = 93.1 m (2 Paints)
40 * ( 1 + 0.5625 ) * ( 1 + 0.5625 * .87 ) * ( 1 + 0.5625 * .57 <-- Stacking Penalty for Third Module) = 122.9 m (3 Paints)

Note: Most frigs do not have exactly 40 m as their sig size... The ship type, and how it is fit will change this value.