Welcome to the informative guide on Path of Exile 2 mechanics, focusing on Leech. As we approach the Early Access launch on December 6, we aim to clarify how leech mechanics function in PoE 2 compared to its predecessor. Understand how leech works, with examples, design philosophy, and the role of instant leech. 

• PoE 2: Leech Mechanics
  • Types of Leech
  • Primary Statistics 
  • Example
  • Keypoints
• PoE 1: Leech Mechanics

↖ PoE 2: Leech Mechanics

If you want to restore a hit resource based on damage dealt, then leech is your ultimate go-to mechanism. However, it is important to remember that leech does not affect damage over time. So, Net leech recovery has to be interpreted gradually with time instead of a single blow.

↖ Types of Leech

↖ Primary Statistics

Now we focus on two main statistics: 

• Percentage of Damage Leeched: Resource recovery can also be defined in simple terms as the percentage of damage done which has been converted irrespective of proportion that has been done.
• Leech Resistance on Monsters: Unfortunately, not every creature is that defenseless, in fact, monsters using this mechanic can resist part of the leeched resource.

In simpler terms, the amount of leech a character gets is equal to the damage taken by the monster after mitigation times the percentage that was leeched. But the twist is that this value is reduced by the percentage of leech resistance to determine what the character had recovered over time.

↖ Example

To better comprehend this mechanic, let us take the example highlighted below:

• A character has a life stealing mechanic of 2% of the physical damage dealt.
• The character is said to have dealt a monster 2000 damage of physical type.
• Life leeched in this case will be: 2/100 * 2000 = 40 life.
• The monster has a 30% resistance to getting leached.
• Final life recovery after the leech is: 40 * 1 – 0.3 = 28 life over time.

↖ Keypoints

• Monster Leech Resistance: Tends to increase this value as the monster's rank increases, to balance the increasing damage that character's inflict.
• Balanced Leech Recovery: Affords across the board efficiency of leeching in all levels of the game be it in the earlier parts of the game in the acts or the late ones.
• Vaal Pact Keystone: Turns all life leech recovery into 'no cooldown' but disables the use of life flasks which are a good tradeoff.

The exact duration of a lunge where a leech is called upon, is said to have no version set time frame to it. However, comments made by developers in an interview indicate a recovery time of about one second per single instance.

↖ PoE 1 Leech Mechanics

The mechanics of leech in Path of Exile are probably more complicated than in any other game, which has given it a level of complexity that is already difficult. For the purposes of this post, we will try not to go deep into the complex mechanics of leech in POE 1. 

• Basis: The damage done to the character in the form of hits is considered after mitigation effects from monsters are determined.
• Multiplication: By the character's percentage damage leech amount.
• Leech Instances: each attack counts and hits at once, leech is applied dynamically also.
• Instance Cap: By default only 10% of the rate resource is returned in every instance.
• Recovery Cap: The default rate of replenishing: life = 20% , mana = 20% , energy shield = 10%, every second; of maximum possible reserves.

Overall, We believe in the case of leech, that for the better mechanics have changed in POE 2, has made the game and engagement of players much clearer and balanced out the strategy.