http://dbd.game/killswitch
How To Calculate Action Speed (Math) In DBD
Let me ask you a simple question. If something slows down your speed of an action by 40%, and that action normally takes 90 seconds, how long would it take? Normally you would say "90 x 1.4 is 126, so it would take 126 seconds", you would technically be right, but in terms of DBD match, you wouldnt.
A lot of actions within DBD use a "charge" system to calculate the speed of an action. So for DBD, an action is 1 Charge per Second (often shortened to C/S by the community), with 90 total Charges, making the action at base take 90 seconds.
If an action were to be slowed by 40%, it would not affect the total amount of Charges needed to complete an action, it will always be the 90 Charges that it is presented to be. Instead, the penalty is applied to the C/S. So instead of taking 1 C/S, it will take 0.6 C/S (-40%, or -0.4 from the base). With this in mind, the action would actually take 150 seconds to complete, since that the time it would take 0.6 C/S to reach 90 Charges.
Before calculating, it is also a really good idea to determine if the number you are using is a multiplicative or additive value, this can often be shown through the wording of the effect, but sometimes it is best to do testing in a Custom Game and/or look up that information from other sources (make sure to site your source if you use any, it's a good idea to provide credit!).
Another VERY important factor to understand is that negative modifiers are applied BEFORE positive modifiers, which often can dampen the positive modifiers since they are modifying a small number. This is especially the case for anything that uses a direct % instead of a flat listed amount, since flat listed amounts are not variable of base amount being modified.
- ((((1 C/S x -Multiplicative Value) - Subtractive Value) x +Multiplicative Value) + Additive Value) = Total Charges (-/+ Value).
So uh… yea. Have fun with this obscure knowledge. Go do math, I guess!
Comments
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Negative modifiers are not applied prior to positive ones, and even if they would be it wouldn't change the outcome: One effect halves action speed, the other doubles it - no matter what you apply first the result is the action speed is unchanged.
For an actual in-game example, if you heal someone with Botany Knowledge equipped while they are under the effect of Mangled, it doesn't matter whether you do the -20% or +50% first or second, the result is the same either way: 16 / 0.8 = 20 → 20 / 1.5 = 13.3 seconds; 16 / 1.5 = 10.6… → 10.6… / 0.8 = 13.3 seconds.
In fact, you can simply apply all modifiers at once, by multiplying negative with positive ones: 0.8 * 1.5 = 1.2 → 16 / 1.2 = 13.3.
The multiplicative and additive distinction is between negative and positive modifiers. The game multiplies negative ones among one another and adds up positive ones. It does this because adding up negative ones would cause -100% (and more) action speed, leading to actions taking forever or actually regressing (fun fact: some things in DbD actually worked like that in its distant past, leading to debuff stacking causing infinite healing times and such).
Adding up positive modifiers on the other hand does not carry the same issue, as all increasing action speed by 100% does is halve action time. It does however have the issue that it diminishes returns on stacked positive effects, and this is what actually "dampens" their impact: If you increase, say, an altruistic heal's action speed by 30% and 50%, the game simply applies this as an added-up 80% modifier (16 / 1.8 = 8.8 seconds), decreasing healing time by 44.44%, whereas applying them successively (16 / 1.5 = 10.6… → 10.6… / 1.3 = 8.2 seconds)/multiplicatively (1.5 * 1.3 = 1.95 → 16 / 1.95 = 8.2 seconds) would decrease it by 48.72%. I think there is an argument to be made that positive modifiers should also be totalled multiplicatively, such that their stacked effects aren't diminished. It wouldn't change too much at all, but it would make some perks just a slight bit more effective in conjunction with others.
Example: We'll Make it and We're Gonna Live Forever both increase one's healing speed by 100%, each respectively doubling it to 200%, but rather than halving the time it takes to heal times two when used together, this is applied as a combined 200% (added onto the base 100% for a total of 300%), so 16 / 3 = 5.3 seconds. But intuitively you would think it gives you a (16 / 2 = 8 → 8 / 2 =) 4-second healing time, or 400% healing speed because it got doubled twice. Which multiplying them instead would achieve (2 * 2 = 4 → 16 / 4 = 4 seconds). Changing this would only reduce the healing time by 1.3 seconds in this very niche, very situational instance, and this is with huge action speed increases at play. So yeah, consider this my petition to make BHVR tally up positive modifiers multiplicatively too.
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Negative modifiers are not applied prior to positive ones, and even if they would be it wouldn't change the outcome
Negative modifiers DO apply before positive ones, and can provide diminishing effect depending on where what and how a modifier is modifying the number. There are many sources that confirm this and even the developers back in 2017-2018 have confirmed this, the issue is that some listed values are not properly represented based on the description of the effect, which again, requires research and testing.
The best example of this is how multiplicative effects can apply to one another, currently there are not many perks that actually apply a multiplicative effect but Call of Brine and Overcharge currently do.
Some effects use a % is a % based on a modified base (not the original base), meaning it will have a diminished effect if it is taking a percent of a small number compared to a percent of a bigger number.
Some perks do use flat additive and subtractive amounts, and those perks wont be affected by something like this, since it relies on taking a % of an unmodified base (the original base). This is more common to see with Movement Speed modifiers.
One thing that I dislike about math in DBD is the fact that flat additive and subtract amounts versus variable percents are not really properly explained, which is why I recommended doing personal research or using external sources, since sometimes things can be listed as percents but be flat amounts, or be listed as flat amounts but be percents.
Post edited by Iron_Cutlass on0 -
Other thing to keep in mind is that negative modifiers are applied multiplicatively, and positive ones additively.
This is so that something can't be reduced to 0, or even negative, and something positive can't exponentially go out of control.
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Actually no. Rather an effective is positive/negative and flat, percent, or multiplicative is entirely based on how it applies. There are some effects effect descriptions can be misleading as to how they apply, which is why I recommend doing research and using external sources.
This is so that something cant be reduced to 0, or even negative.
Most effects within a game are % based on a modified %, this is the most common modifier to see, these effects normally apply after flat additive/subtractive amounts this way you are only adding/removing a % based on the modified amount which would inherently be smaller.
We have not had math yet that would result in us reaching 0 action speed, but Im sure the developers though of this and put a cap on negative effects on action speed to prevent a situation like such, otherwise I would seriously lose all faith in this game.
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The devs have stated what i said to be fact in several places.
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Y'all are making me feel stupid. I'm lost.
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Again, Im not completely disagreeing, a lot of negative effects are just straight up multiplicative, but some are based on % of the modified amount, again, to provide a diminished effect and prevent action speed from reaching zero. It is based on how the effect is applied, and there are some effects, where if you test it, and check the math, they are not ALL multiplicative, most are, but not all.
IDK HOW MANY TIMES I HAVE TO SAY THIS, but just check ingame through testing or do research to see how it applies, not all effects will apply the same or how you think they would apply.
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I’ll explain the increase bonus cause I actually know that one more
A Gen takes 90 charges. 1 charge=1 second. So 90 charges is 90 seconds to compete one generator.
let’s say you run the perk deva vu that gives a 6% bonus speed.You take the 6% and move the decimal to the left twice so now it’s .06
You take 1 second and you add the .06, so 1+0.06 is 1.06.
then you take the original 90 seconds and divide that by your result that being 1.06.
90/1.06=84.906 rounded up would be 85 charges/seconds.So in conclusion with the math done, deva vu would reduce the time to do gens by exactly 5 seconds.
That’s what I know about the speed increase I hope that’s simple enough to understand
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What you said is the definition of multiplicative.
Let say we look at 2 situations. Gens take 90 seconds, or 90 charges, survivors add 1 c/s.
If i have 2 effects that increase my gen speed by 10% and also by 15%, they add together to 25% and increase my speed to 1.25 c/s, making the gen take 72 seconds.
If i have 2 effects that decrease my gen speed by 10% and also 15%, that are multiplicative and applied stacking. So i start at 1 c/s, reduced by 10% becomes 0.9 c/s reduced by 15% becomes 0.765 c/s Which makes the gen take 117.6 seconds, which is actually about 30% longer.
The reason for this is because lets say they were swapped, and positive effects were multiplicative, and negative effects were additive.
If we had say, 5 effects that increase my gen speed by: 20%, 50%, 10%, 5%. 25%. In an additive world, this increases my gen speed by: 110%, effectively more than doubling my gen speed to 2.1 c/s. But in a multiplicative world, this would be significantly higher at 2.59 c/s which is almost a 160% increase. So its possible for them to quickly stack out of control.
If we had 5 effects that negatively decrease gen speed by the same amounts: 20%, 50%, 10%, 5%, 25% and it were multiplicative, your 1 c/s becomes 0.2565 c/s. But if it were additive, it becomes -10%. So repairing a gen actually unrepairs it at 0.1 c/s. Thus being out of control quickly.
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No, if we are talking about action speed, all modifiers are applied at-once, and even if they weren't the order wouldn't matter. Mathematically it doesn't matter whether you first decrease a value multiplicatively and then increase it, or vice versa.
If you are talking about charges instead, you would have to give me actual game examples, because as far as I know BHVR either made them apply a flat +/- value, or with charge efficiency and inefficiency instead of having effects apply to actual charges, made them apply to the charge depletion rate, in which case you use the formula "charges divided by ((1 / negative modifier) * (1 / positive modifier))" to calculate the effective charges, where order again doesn't matter. For example: Botany Knowledge applies a 20% charge inefficiency to med-kits, meaning for every 1 charge of a med-kit used, only 0.8 charges of healing progress happen, so you need 1 / 0.8 = 1.25 med-kit charges per every 1 charge of healing progress, or 16 / 0.8 = 20 med-kit charges to fully heal for one health state; Streetwise applies a 25% charge efficiency, meaning for every 1 charge of med-kit used, 1.25 charges of healing progress happen, so you only need 1 / 1.25 = 0.8 charges of med-kit for every 1 charge of healing progress, or 16 / 1.25 = 12.8 for a full heal. To determine the med-kit's effective total charges when both are equipped, it doesn't matter whether you first apply the rate reduction or increase, both cancel each other out either way: 1 / 0.8 = 1.25 → 1.25 / 1.25 = 1 charge of med-kit for 1 charge of healing progress; 1 / 1.25 = 0.8 → 0.8 / 0.8 = 1. Or just 1.25 * 0.8 = 1.
How do Call Of Brine and Overcharge interact mathematically, and do you have evidence for this? Because again, if we just take them to apply multiplicatively to the base regression rate of 0.25 charges a second, it doesn't matter whether you apply Overcharge's * 0.85 decrease or COB's * 1.25 increase first, the result is the same (0.265 charges a second, or 106.25% regression rate, obviously growing to 1.3 * 1.25 = 1.625 → 0.25 * 1.625 = 0.4 charges a second, or 162.5% regression rate).
The mistake in your logic with "positive percentual modifier of a smaller number is less" is that you neglect that if you apply the positive modifier first, the negative percentual modifier applying to that then bigger number will also be more. It cancels each other out, so the order doesn't matter and you can instead just apply them together (so for Overcharge and COB, 0.85 * 1.25 = 1.0625; 0.25 * 1.0625 = 0.265).
I do agree that these things aren't sufficiently (or really at all) explained or even just stated properly in the game. How effects stack is not readily available knowledge, and that should be remedied.
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IDK HOW MANY TIMES I HAVE TO SAY THIS, but just check ingame through testing or do research to see how it applies, not all effects will apply the same or how you think they would apply.Saying it doesn't really matter. If you have an example that disproves what the others are saying, just tell us the perks and people will go try them. Something like 'what you all are saying means X and Y should result in Z, but actually go run X and Y and you'll see it results in A'. That will make things much clearer on whether there is an example or if people are just talking past each other.
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During the Hex: Thrill of the Hunt meta I explained how some effects apply their modifiers since some people were making posts saying "just use Counter Force" when Counter Force was not a counter. People were throwing out odd numbers with how long it would take so I did some test and some math and calculated that Hex: Thrill of the Hunt specifically would apply before Counter Force, and since Counter Force was a variable % (not a flat %), it would receive a diminished effect from Hex: Thrill of the Hunt slowdown down the action speed first.
Keep in mind, this is not as detailed as it was in the original thread but it an example of an interaction between positive and negative modifiers that does display that negative does go before positive. Here is the original thread if you want a look for yourself:
DBD Math can be really weird, sometimes things you think would apply a certain way just dont, I often tend to record videos of stuff and trim the clips to see the time it took for an action to be completed, this way I can at least work backwards to determine how different perks are applying their values. Sometimes DBD also changes effects, sometimes the way that they apply can be changed when a perk is buffed/nerfed/reworked, which results in the time an action will take being altered by it.
To put it bluntly, stuff like this can be really complicated.
The way I put it is a bit weird, so allow me to explain it a bit better.
Typically when you think of multiplicative values in a game, they typically follow everything else so they have the highest potential, DBD is a bit different in the sense that multiplicative values go before additive and variable percent values, this is because multiplicative values are designed specifically to scale off other multiplicative values being present, this is why effects like Call of Brine being stacked with Overcharge were so strong before they were hard nerfed.
DBD uses a lot of multiplicative values for negative modifiers since, as you mentioned, it makes it really difficult to reach an action speed of 0 C/S. But, DBD does have additive and flat modifiers that are negatively applied to action speed, which was my main point, that effects like that do exist. Specifically, the best example of this is how Thantaphobia affects Totem Cleansing Speed, since it actually provides a variable percent amount that happens after multiplicative modifiers (Hex: Thrill of the Hunt) are applied.
I come from the Warframe community, so a lot of what I do is math, spreadsheets, timing things, recording data, etc, it's needed for minmaxing gear, and this is just based on my own test, but I could have very well gotten the math wrong in some areas, I am human and I could have possible made a mistake along the way with my testing.
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Like i said, Nothing personal, but i'm going to take word of official statements from devs rather than random people on the internet. The devs have stated that all negative modifiers are multiplicative, and positive modifiers are additive.
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Nothing personal, but Im going to take word of official statements from dev rather than random people on the internet.
Oh, Im not talking it personally, I just thought it would be a good idea to further clarify my ideas and thoughts since Idk how well articulated they were.
Im not a developer, I dont have access to the game's code, Im just stating information based on personal observations and testing but DBD is DBD and there is bound to be some jank. 👍️
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During the Hex: Thrill of the Hunt meta I explained how some effects apply their modifiers since some people were making posts saying "just use Counter Force" when Counter Force was not a counter. People were throwing out odd numbers with how long it would take so I did some test and some math and calculated that Hex: Thrill of the Hunt specifically would apply before Counter Force, and since Counter Force was a variable % (not a flat %), it would receive a diminished effect from Hex: Thrill of the Hunt slowdown down the action speed first.But this doesn't seem to disagree with what anyone, such @zarr is saying in this thread. The order of operations is not relevant here.
1*0.3*1.2=0.36
1*1.2*0.3=0.36
That is, and has always been, my understanding of how math in DBD works.
If we throw in something like leader the formula should be
1*0.3*(1+0.2+0.25) = 0.435
Writing it as
1*(1+0.2+0.25)*0.3=0.435
Let's do Thana with all 4 survivors injured, CF, and Leader
1*0.3*0.8*(1+0.2+0.25) = 0.348
Let's put the additives in the middle:
1*0.3*(1+0.2+0.25)*0.8 = 0.348
Hypothetically, let's imagine more than one leader could apply so we have a both 70% increase and a 70% decrease.
1*(1+0.2+0.25+0.25)*0.3 = 0.51
1*0.3*(1+0.2+0.25+0.25) = 0.51
What comes first is irrelevant. Increases are added to together before we start multiplication, but otherwise everything just gets multiplied together.
Post edited by crogers271 on0
