In PoE 2, Evasion is pivotal in your defensive systems. Still, it is odd that its mechanics are not well laid out within the game itself, leaving many players scratching their heads trying to figure out how it actually works. Moreover, most of the information found from outside sources is unreliable due to the changes made in PoE 2's evasion formula. This guide aims to provide a comprehensive and modern interpretation of the mechanics concerning evasion, including the relationship between Evasion, Accuracy, and the new 'Chance to Hit' formula.

• Evasion & Accuracy
• Chance To Hit
• New Evasion Formula
• PoE2db Bug
• Evasion Spreadsheet
• Entropy
• Evasion Affixes

↖ Evasion & Accuracy

Evasion is what decides whether your character gets hit or not. This mechanic is dependent on how much an attacker's Accuracy Rating affects the character's Evasion Rating.

Key Points:

• Evasion Check: The game calculates whether an action is a hit or miss based on how the attacker's Accuracy Rating compares to the defender's Evasion Rating.
• Limitations: Certain moves cannot be evaded such as Area of Effect (AoE) moves or boss slams. Only when using the Acrobatics passive skill can these attacks be avoided.
• Dynamic Interaction: Greater Evasion Rating also lowers the chance of getting hit but is directly balanced against the attacker's Accuracy Rating.

Understanding this interaction is crucial for building an effective evasion-based character.

↖ Chance To Hit

In PoE 1, the Chance to Hit formula was relatively straightforward; everyone knew how it worked. However, with the advent of PoE 2, this calculation becomes more complex due to certain changes. 

Observations from Testings

• Old Formula Issues: Using PoE 1's formula in PoE 2 often results in incorrect values, such as negative chances to evade.
• Example:
  • A level 37 character with 797 Evasion Rating faces a level 37 monster with 716 Accuracy Rating.
  • Using the old formula, it would require unrealistically high Evasion (e.g., over 2,000) to achieve a positive chance to evade.
• Conclusion: The old formula is no longer valid, necessitating a new approach to calculating hit and evade chances.

↖ New Evasion Formula

After extensive testing and research, a new evasion formula has been identified in PoE 2. This updated formula simplifies calculations while maintaining accuracy. 

Key Points:

• Source Verification: The updated formula was confirmed through the Path of Building tool (PoE 2 fork) and developer communication with Grinding Gear Games (GGG).
• Formula Overview: The new formula incorporates a simpler calculation method compared to PoE 1 but remains distinct from its predecessor.
• Testing Results: Using the new formula provided more accurate results that aligned with in-game character sheet values.

Formula Comparison Table:

↖ PoE2db Bug

What is termed the bug of PoE2db has to do with the fact that the accuracy ratings of certain monsters are being wrongly calculated. In particular:

• Base Accuracy Multiplier Issue: monster accuracy ratings seem to be incorrectly multiplied (e.g., x2 instead of x1).
• Consistency Across Monsters: Most monsters inaccurately apply a base multiplier of x2, which becomes a prevalent error.

Example of the Bug:

Why It Matters?

The bug affects how players calculate their evasion rating targets. If you rely on PoE2db for accuracy data, you may overestimate monster accuracy and adjust your build unnecessarily.

How to fix?

Use base accuracy values ​​without applying inflation multipliers. Test your evasion abilities against game results to verify your calculations.ions.

↖ Evasion Spreadsheet

The Evasion Spreadsheet is a tool designed to help players calculate their chance to evade attacks based on monster accuracy and their own evasion rating. It accounts for attacker level and accuracy scaling as you progress in the game.

Key Features:

1. Accuracy vs. Evasion Mapping: Maps attacker levels and accuracy values against defender evasion ratings (e.g., from 0 to 63,000). Allows players to test scenarios and determine their chance to evade.
2. Dynamic Scaling: As you level up, monster accuracy increases (e.g., from 70 at level 5 to 75 at level 6). If your evasion rating remains static, your chance to evade decreases over time.

Example Table:

How to Use It?

1. Input your character's current evasion rating.
2. Select the level and expected accuracy of attacking monsters.
3. Review the calculated chance to evade and adjust your build accordingly.

↖ Entropy

Entropy in PoE 2 is a system that prevents streaky outcomes in evasion mechanics by ensuring a more consistent distribution of hits and misses over time.

How It Works?

• Initial Roll:  When a monster attacks, a random number between 0 and 99.99 is rolled for entropy.
• Adding Accuracy:  The monster's chance to hit (e.g., 30%) is added to the entropy roll.
• Threshold Check:  If the total value is below 100, the attack misses. If it exceeds 100, it hits, and entropy resets for the next attack.

Example Process:

Why It's Important?

Prevents random, frustrating hit-or-miss streaks which can disrupt the flow of frustrating gameplay. Assists players in formulating the number of attacks they expect to evade during an encounter.

↖ Evasion Affixes

Evasion affixes are critical for enhancing your character's ability to evade enemy attacks. 

1. Types of Evasion Modifiers

Evasion modifiers can be categorized based on their source and functionality:

• Flat Evasion Increases: Found on armor pieces (e.g., chest, gloves), Local modifiers that apply specifically to the item they are on.
• Percentage Evasion Increases: Found on jewelry (e.g., rings, amulets) and passive skill trees, These contribute to a global additive pool that multiplies your base evasion rating.

2. Jewels and Passive Tree Interaction

Jewels can enhance specific nodes on the passive tree, offering localized improvements to evasion. These modifiers can synergize with other global and local increases for significant boosts.

3. Acrobatics Keystone

• Effect: Acrobatics applies a less multiplier (e.g., 0.3x) to your total evasion rating.
• Purpose: Mitigates the inability to evade large boss slams or heavy hits.
• Trade-off: Reduces overall evasion but provides a safety net against unavoidable damage.

Grasping how evasion works in PoE 2 involves looking into affixes, interactions with the passive tree, and keystones such as Acrobatics. Although the system is well-crafted, providing clearer feedback would make player experience regarding mechanics much more seamless.