news\ Feb 16, 2012 at 10:11 am

BioWare explains Mass Effect 3 'Power Stat Upgrades' math formula


There's been a lot of question surrounding the power bonuses in Mass Effect 3 since the release of the demo a few days ago, with some going so far as to say the system is broken.  BioWare, on the other hand, argues against that theory and has the numbers to back it up.

In a detailed post on the developer's forum, Mass Effect 3 senior designer Manveer Heir provided fans with the mathematical formula used to calculate how bonuses are applied to players' stats in Mass Effect 3.

Unlike Mass Effect 2, which Heir admits is fairly similar in formula, BioWare chose not to release the final numbers to the players with that game.  This time around, however, BioWare is doing it to "allow the hardcore RPG player to maximize their potential and know what is happening."

"We realized this would be a very small percentage of people that do this so instead of confusing people and trying to explain everything in game with complicated formulas, we do the math in the background, give you guys the results that matter and let you make your choices from there," Heir said. "The truly hardcore can read this, hopefully helpful, forum post to understand everything further."

"I promise you the numbers we are giving you are correct and are calculated correctly and we spent lots of time discussing the formulas, when to use which ones, and how players will understand. We understand this isn’t clear in-game how the formulas work, but the important information is given to you the player. You are told the end result of your action as well as the percentage increase. This really only breaks down when you think the game is broken and decide to do the math on your own and realize you don’t have the correct formula to solve the problem."

Below are the three different types of formulas used to calculate power bonuses, along with their mathematical explanation.  And yes, Heir and BioWare have "spent a lot of time making sure the numbers were correct and this is all working as intended, even if it doesn’t make perfect sense at first glance."

Prepare for your math lesson, fans.  At least it's useful math this time around!

Formula 1 – Normal Power Upgrades

The vast majority of powers data upgrades fall under this, such as damage, force, and impact radius. Most notably, power recharge speed (aka cooldown) does NOT fall under this formula.

New Value = Base Value at Rank 1 * (1.0 + Sum of all rank bonuses + Dynamic Bonuses)

Base Value at Rank 1 is simple. Whatever damage (or whatever is being upgraded) is at rank 1 of that power is the base value. This is what all the percentages are off of.

Sum of all the rank bonuses are the bonuses of every other rank that you have bought added all up. So if Rank 3 upgrades damage 10% and you bought Rank 4 evolve that upgrades damage 15% and at Rank 6 you bought the evolve that upgrades damage 25% then the sum of the rank bonuses are 50% (add all three numbers). You only add in rank bonuses for the stat you are upgrading that you have bought. Note, this value is expressed as a floating point number so 50% = 0.5. 100% = 1.0.

Dynamic Bonuses are from things like your passives and weight capacity. So you could have 100% bonus total by having a 70% bonus from weight capacity, 10% from wearing certain armor, and 20% from your passive power. Note, this value is expressed as a floating point number so 50% = 0.5. 100% = 1.0.

So why do we calculate it like this instead of just taking the current value and multiplying it by the upgrade amount (like 25% for example)? Balance is a big reason. If the upgrade modifies the current value, the upgrade is more useful for players who have a higher value from things like passives and all that. This means powers can quickly become overpowered or an upgrade is useless for some players and ridiculously powerful for others. This becomes hard to balance and manage. So all upgrades go off of the BASE value (and the base value is calculated before any passives, armor, weight capacity, etc stuff is accounted for).

Formula 2 – Recharge Speed Upgrades

Recharge speed (aka cooldown) use a formula called divide by bonus sum. The formula is as follows:

New Value = Base Value at Rank 1 * (1.0 / (1.0 + Sum of all rank bonuses + Dynamic Bonuses))

The definitions of the values are the same as above. So if recharge speed is 10 seconds at Rank 1, the sum of your rank bonuses is 50% and the dynamic bonuses total at 25%, using the formula above what you find is the value is 5.7. Only recharge speed is calculated using this formula. Also, it should be noted that Henchmen power recharge speeds are always double what Shepard’s recharge speed is (there may be one or two execptions, but those are close to double). This is to stop the henchmen from being overpowered.

Formula 3 – Hard Value Bonuses

This formula is used for stats that are expressed as percents. So, normally if you are upgrading something like Force, that is measured in Newtons. So you are upgrading 25% to the base 100 N of Force. However, what do you do when the stat you are upgrading is Weapon Damage Bonus, like many of the passives have. Weapon Damage Bonus is expressed as a percentage.

So Rank 1 Weapon Damage Bonus may be 10%. If we say at rank 2 the Weapon Damage Bonus increases by 50% what is the correct result for total weapon damage bonus now. If you used formula 1, it would be 15%. But that goes against what people expect, because you are increasing a percent by a percent. Instead, you expect the numbers to add together. So a 50% increase to 10% should be 60%.

Because of this we created a different formula for these sorts of stats. This just makes the numbers work like what players expect. The formula is simple

New Value = (Base Value at Rank 1 + Sum of Rank all rank bonuses) * (1.0 + Dynamic Bonuses)

Well, those are the three formulas.  Perhaps if I had paid more attention in school I'd understand the formulas a little better.  Then again, who would've thought all of that useless junk learned in school would actually be useful in something so important as Mass Effect 3.  I don't even think Rainman could figure this stuff out.  But maybe it's just me.  Heck, if I was any good at math I wouldn't be doing this for a living.

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