Guide to HP and Mana leech in PoE (at last until 9.3)

This guide is based on numbers from the character screen, the HP/s and MP/s stats. Guide is also based on Mark telling me where I screwed up.

In Path of Exile, you do not get HP and Mana back instantly from leech. You get it back over time, at a rate that is equal to a certain percentage of your total HP or Mana per second.

-For life leech, the rate appears to be ~20% of total hp per second.

-For mana leech, the base rate appears to be ~12.5% of total mana per second.

The item mod "XX% Increased Mana Regeneration Rate" increases your mana leech rate. This mod just went from useless to awesome in my eyes after I found this out (Mark informs us below that this is a bug).

So there are two ways to improve your leech: increasing your leech percentage, or increasing your leech rate by increasing your total HP or mana pool (or using the bugged +mana regen stat). You may hit a point where more mana leech % does not help you for the purposes of sustained DPS, in which case try to find +mana items instead.

"

Mark_GGG wrote:

What do you mean by 'cap' here? Cap is usually used to describe a situation where something has a variable value but cannot exceed a certain amount, which isn't the case here (unless leech has majorly changed since last time I changed it - will check Monday) - there's no capping occuring, simply all leech occurs at a set rate.

Oh, and those stats weren't meant to affect leech and have already been fixed for next patch (due to someone finding out they were affecting potions too).

Indeed. I was trying to produce a situation where I got a number that was not 12.5%/s, and couldn't...at which point I realized something was wrong :D I'll edit to reflect this.

I'm trying to think of how to word this, because there is a cap of sorts. You'll easily hit a point where you're getting that mana rate 100% of the time. And with sustained DPSing, the total mana returned is unimportant, only the rate. So I guess my revised meaning of 'capped' is that additional leech % is no longer helping you (for the purpose of sustained DPS).

EDIT: "Capping" in more detail, to see if this makes any sense :)

Say you have 400 mana, so your leech return rate is 50 mp/s. You built your character for a lot of leech, so you have 7% mana leech.

Using some hypothetical terrible bow, you do 100 damage, shooting once per second. So after every hit, you will return 7 mana at 50 mp/s, so you will return 7 mana within .14 seconds. Your effective MP/s from leech is 7 mp/s.

Say you now have some realistic items for a high level ranger, so you're hitting for 400 damage 6 times a second. Each hit will return 28 mana over .56 seconds. But the next hit arrives every .167 seconds! So your effective rate of return is capped at 50 mp/s.

So the variable thing here that is being capped is effective MP/s, rather than the actual rate of return. Since you do 2400 DPS, you're not benefiting from leech beyond 3%, for the purposes of sustained DPS.

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Mark_GGG wrote:

What do you mean by 'cap' here? Cap is usually used to describe a situation where something has a variable value but cannot exceed a certain amount, which isn't the case here (unless leech has majorly changed since last time I changed it - will check Monday) - there's no capping occuring, simply all leech occurs at a set rate.

How is the rate set ? How much is the leech spread over time ?

"

Mark_GGG wrote:

What do you mean by 'cap' here? Cap is usually used to describe a situation where something has a variable value but cannot exceed a certain amount, which isn't the case here (unless leech has majorly changed since last time I changed it - will check Monday) - there's no capping occuring, simply all leech occurs at a set rate.

I'd like to draw a distinction between "leeching" and "gaining" mana:
leeching: the calculated amount of mana leeched from an enemy that you will eventually gain (but have not yet gained)
gaining: actually getting mana refilled into your orb


So, say I have 200 mana. If I am leeching less than 25 mana per second, getting more leech will continue to increase the amount of mana per second I am gaining. I have not yet hit the cap.

But, once I am leeching more than 25 mana per second, the excess just builds up as "credit". Even if leeching 10,000 mana per second, I will only be gaining 25 mana per second. I will continue to gain 25 mana per second, even after combat has long finished, until the "debt" is paid off.



So, while there is no cap on the amount of mana you can leech, there is a cap on the amount of mana you can gain per second from leech. Assuming aimless is correct, this is 12.5% of total mana per second.

So OP was right. In short, the rate is caped, but not the amount.

"

Mark_GGG wrote:

Oh, and those stats weren't meant to affect leech and have already been fixed for next patch (due to someone finding out they were affecting potions too).

Is there a reason aside from "we didn't expect this" that you're removing this? It seems like a nice little hidden mechanic that adds flavour to the game.

"

Dreggon wrote:

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Mark_GGG wrote:

Is there a reason aside from "we didn't expect this" that you're removing this?

It's excessively overpowered for flasks, so I can understand removing that. I'm sure the bug is affecting all forms of mana gain in the same way, so fixing it would affect all the same.

Throwing in my 2 cents to this, which is

Mana leech in its current form is next to useless as it doesnt work in the way we're used to as in giving you chunks of mana back per attack instantly

I always have to chug potions to keep my attacks going, leeching is just too slow. Especially so on rangers and such.

"

Dreggon wrote:

"

Mark_GGG wrote:

Oh, and those stats weren't meant to affect leech and have already been fixed for next patch (due to someone finding out they were affecting potions too).

Is there a reason aside from "we didn't expect this" that you're removing this? It seems like a nice little hidden mechanic that adds flavour to the game.

Seconded!

It's gonna make another mod on items and passives crappy.