Reduced Mana Reserve Implicit Corruption not working

Using Enlighten level 3 and 1% Reduced Mana Reserved corruption on a jewel for Vitality, Malevolence and Herald of Agony doesn't allow for all 3 to be active (total Mana Reserved should be 101% without the corrupt, therefore with the implicit it should allow for all auras to be on - 100% reservation).

Helmet with links:



Jewel with Reduced Mana Reserved implicit:



Bug report ref screenshot:

https://imgur.com/a/3XjhD2k

Edit: Please read further below for maths for maths' sake post explaining further.

Edit 2: I believe this belongs in Bug Reports section, but it was moved to Discussion when clearly there is an issue with how rounding is done. Oh well.

It's working as intended.

The implicit applies against each source of Mana Reservation individually, and so you need more than 1% for it to have an effect due to the game rounding down.

Take Malevolence for example. If you reduce 50% Mana Reservation by 1%, that's 1% of 50% - which is 0.5%. So your Malevolence skill should reserve (50% - 0.5% =) 49.5% of your total Mana. The game then rounds that 0.5% down to 0%, so no reduction is applied. If you had 2% Reduced Mana Reservation, that 50% would be reduced by 2%, which is 1% of your total Mana, and so Malevolence would reserve (50% - 1% =) 49% of your total Mana.

This is a common mistaken report. If you search only the Bug Reports section of the forum for "reduced mana reservation", you'll get 796 pages of results, each including 10 posts. (Link)

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Sarno wrote:

It's working as intended.

The implicit applies againt each source of Mana Reservation individually, and so you need more than 1% for it to have an effect due to the game rounding down.

Take Malevolence for example. If you reduce 50% Mana Reservation by 1%, that's 1% of 50% - which is 0.5%. So your Malevolence skill should reserve (50% - 0.5% =) 49.5% of your total Mana. The game then rounds that 0.5% down to 0%, so no reduction is applied. If you had 2% Reduced Mana Reservation, that 50% would be reduced by 2%, which is 1% of your total Mana, and so Malevolence would reserve (50% - 1% =) 49% of your total Mana.

This is a common mistaken report. If you search only the Bug Reports section of the forum for "reduced mana reservation", you'll get 796 pages of results, each including 10 posts. (Link)

Fair enough, I might have not seen it correctly on PoB or my version might have been bugged (current version shows -1% as it should based on this formula for calculation, but while I was planning it it was showing a different number hence why I was confused). Although I don't quite understand the logic of rounding pre-all calcs, but I guess that's an internal design decision so I won't prod at it too much.

Thanks for the clarification. Will redo my build to account for this accordingly.

Apologies for double post in advance/lengthy maths for maths' sake post.

Re above mentioned working as intended, I thought about it but it doesn't make sense to me (logically and mathematically). Rounding is an operation normally done either for "prettiness" of the output, or because the next operation does not work with floating point values. Here is my deduction (from a programmer's perspective):

In the current case from my understanding, the rounding is done due to the Aura being unable to reserve a floating point value, which makes sense:

- If lets say we want to reserve 35.73% Mana and we have 100 Mana total, there is no way to reserve 35.73 Mana, as Mana works on an integer base.

In this case, rounding up or down is fine (I'd say using standard mathematical rounding - up in this case - would make more sense since it's past .5, and the game seems to employ this method, but I could be wrong on that).

However, let us take the example of the issue I reported:
- I am taking Malevolence (50% reservation), Vitality (35% reservation) and Herald of Agony (25% reservation).
- Each of these auras is benefiting from a Enlighten Level 3 Gem, therefore we can reduce their Mana used (reserved) as follows (based on 92% mana usage multiplier):

* Malevolence - from 50% to 46% Mana Reserved (4% reduction)
* Herald of Agony - from 25% to 23% Mana Reserved (2% reduction)
* Vitality - from 35% to 32.2% (2.8% reduction)

Total Mana Reserved: 101.2%
Total reduction (from Enlighten): 8.8%

Note that I did not round Vitality just yet. This is important as normally mathematical and algorithmic operations are done with the absolute value wherever possible (i.e. value should stay as is for now).

Next we can apply the reduction from the Mana Reserved (in this case 1%):

* Malevolence - from 46% to 45.54% (0.46% reduction)
* Herald of Agony - from 23% to 22.77% (0.23% reduction)
* Vitality - from 32.2% to 31.878% (0.322% reduction)

Total Mana Reserved: 100.188%
Total reduction (from Mana Reserved reduction): 1.012%

Note that no rounding has been done yet. As we can see based on the calculation so far, if we were to apply rounding (based on a round operation, personally "opinionated" I'd say always doing mathematical round would be correct), our values would therefore be:

Total Mana Reserved(rounded): 100%
Total reduction (from Mana Reserved reduction, rounded): 1%

It is important here to note that the order this is calculated is irrelevant, i.e. in Maths:

(46 + 23 + 32.2) * 0.01 = 46 * 0.01 + 23 * 0.01 + 32.2 * 0.01

Therefore whether it is done per Aura or as total is not relevant. However in Path of Exile's case, it is likely done the second way due to the game not having to account for multiple auras when calculating said reduction(i.e. what if you only have 1 aura active at a time, reduction is only counted for the active one and it makes more sense to pass singular auras to the algorithm and then sum the results).

I guess the questions I have here are:

- Mathematically, we should be able to use 3 auras with Enlighten level 3 and 1% Reduced Mana Reserved (as per calculated above), but the game does not allow this, so was that done due to balance reasons or is it residual from before which the community has taken as a "Working as intended" without too much looking into it (possibly someone might have before, if that is the case, my apologies, but filtering through hundreds of posts is not feasible)?

- Going forward (PoE 2), where it was said that we could turn on all auras at once, will this then be used too? (Considering you'd assume if you are triggering all 3 then the calculation should be done for all of them together, so this will make even less sense as reason to be done this way and not allow the 3 to be on at once.)

Suggestion:
- Why not record the reduction made in some way before rounding (depending on when this reduction is calculated, whether with Enlighten or after), and adjust accordingly to fit cases such as the one mentioned above where we can clearly see we are going to the 1% reduced Mana Reserved and therefore we should be able to use all 3 Auras? (whether this is to be stored in a variable etc. in code is up to you guys, just my suggestion for a possible solution)
- Another way is to have it recalculated and if the total has now been reduced by a full value (i.e. 1% in this case), then the value is done to fit the case (will have to account for not yet triggered auras so that they can be fit in based on unreserved mana left and this calculation of the reduction).

Sorry but Sarno is 100% correct here. This is by design of GGG and have been confirmed by GGG several times. So no bug here.
You will need a level 4 gem or get more jewels with the 1% reduced.

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HanSoloDK wrote:

Sorry but Sarno is 100% correct here. This is by design of GGG and have been confirmed by GGG several times...

I do not believe you read my second post where I said it is likely a design decision. The math's for math's sake post clearly shows me just brainstorming as to a solution as what the design is currently, shows a mathematical inconsistency of basic application of operations.

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HanSoloDK wrote:

...So no bug here.
You will need a level 4 gem or get more jewels with the 1% reduced.

Let me pose the question another way, how much is 1% out of 101?
Refer to below quote if you would like to say that every aura is calculated separately:

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It is important here to note that the order this is calculated is irrelevant, i.e. in Maths:

(46 + 23 + 32.2) * 0.01 = 46 * 0.01 + 23 * 0.01 + 32.2 * 0.01

However, how the above was designed into an algorithm is what has been done incorrectly (as it defies mathematical laws the way it is right now).

Manacost is just always rounded up so you need to get your end total below 100%

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Torguemada wrote:

Manacost is just always rounded up so you need to get your end total below 100%

This is incorrect. I can give you an example:
- Level 3 Enlighten (92% Mana multiplier) linked to Vitality (35% Reservation). If you do the math it will be 32.2% (float), ingame it is 32%. Therefore it was rounded down.

Oh lol your just doing incorrect math, thats the problem

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injustcorr wrote:

It is important here to note that the order this is calculated is irrelevant, i.e. in Maths:

(46 + 23 + 32.2) * 0.01 = 46 * 0.01 + 23 * 0.01 + 32.2 * 0.01

First your statement about order being irrelevant is simply false.
Secondly Your calculation is wrong anyway, its should be like this
(46*0,99)+(23*0,99)+(32*0,99)
=(45,54)+(22,77)+(31,68) and since reservation is calculated on per aura bases those are all invidually rounded so end result is
46+23+32=101
if you calcualted them all together first then you would end up with
101*0,99=99,99 witch would indeed get you to even 100%, but that wouldn't make any sense, all the auras are seperate spells with seperate mana reservation costs.

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Torguemada wrote:

Oh lol your just doing incorrect math, thats the problem

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injustcorr wrote:

It is important here to note that the order this is calculated is irrelevant, i.e. in Maths:

(46 + 23 + 32.2) * 0.01 = 46 * 0.01 + 23 * 0.01 + 32.2 * 0.01

First your statement about order being irrelevant is simply false.

Do lecture me on how the ordering of the following formula matters:
(A + B + C)*D = A*D + B*D + C*D

Or do you think that (B + A + C)*D would give a different result?

I'd be keen on learning a new mathematical law here seeing as apparently this one does not hold.

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Torguemada wrote:

Secondly Your calculation is wrong anyway, its should be like this
(46*0,99)+(23*0,99)+(32*0,99)
=(45,54)+(22,77)+(31,68) and since reservation is calculated on per aura bases those are all invidually rounded so end result is
46+23+32=101
if you calcualted them all together first then you would end up with
101*0,99=99,99 witch would indeed get you to even 100%, but that wouldn't make any sense, all the auras are seperate spells with seperate mana reservation costs.

Also, it is 0.01 as that was the calculation for the specific reduction from reduced Mana Reserved. How you calculate this final result is not relevant simply due to the fact that the sum of it is 1.012 as I stated.

And lastly, if you had read what I wrote you would have clearly seen that I did mention that it is done per aura currently hence why it is 101% instead of the 100.188% which it would be if it was done the way I did the calculation. However, let me put this another way:
The #% reduced Mana Reserved is a global multiplier, i.e. yes it affects every aura separately. However, what this means also (from a mathematical and programmatic perspective), is that the sum of the local values with this applied should equal this applied on the sum of the local values without it applied. Currently, this is not the case. I will not discuss the sense you are talking about as that is 'game sense' which is build from playing the game, instead of 'algorithmic sense' which is what it should be mathematically.

Should I also add that rounding in this specific mechanic is entirely unnecessary (from observation), as there are cases where Mana is an uneven number anyway, so therefore when a percentage of it is taken it is rounded further anyway (if I take 50% of 673, I will get 336.5, which I cannot reserve .5 mana so this will be rounded). So why even round the % of Mana Reserved by the Aura? This will introduce a case where the total will be something like 100.188% as in this case, therefore 3 auras would not be possible, but atleast that will be mathematically consistent.
Is it a bit clearer now?