Lemontropia-Suite/docs/ARMOR_DECAY_FORMULA.md

4.2 KiB

Entropia Universe Armor Decay Formula

Source: "A Most Complete Guide to Armors (2020 Edition)"
Formula Author: Hijacker27 (confirmed through testing)
Date: 2026-02-09


Armor Decay Formula (VU 15.15)

Decay (in PEC) = damage_absorbed * 0.05 * (1 - durability/100000)

Where:

  • damage_absorbed = Amount of damage the armor piece absorbed
  • durability = Armor's durability stat (varies by armor type)
  • Decay output is in PEC (divide by 100 for PED)

Armor Economy (hp/pec)

The economy can be calculated as:

hp/pec = 20 / (1 - durability/100000)

Or simplified:

hp/pec ≈ 20 + (durability/5000)

Unlimited Armor Protection Costs

Armor Durability hp/pec dmg/100 PED decay
Ghost 2000 ~20.41 204,082 damage
Gremlin 2950 ~20.61 206,079 damage
Adjusted Nemesis 3400 ~20.70 207,039 damage
Angel 4000 ~20.83 208,333 damage

Analysis: Using Angel instead of Ghost saves ~2 PED for every 100 PED of decay (2% savings).


Limited (L) Armor Protection Costs

Note: Formula may differ for Limited armors with >10k durability (research ongoing).

Armor Durability hp/pec dmg/100 PED vs Ghost
Martial (L) 13,000 ~22.99 229,885 ⮟ 11.22% less decay
Mayhem (L) 13,300 ~23.07 230,680 ⮟ 11.53% less decay
Angel (L) 14,000 ~23.26 232,558 ⮟ 12.24% less decay
Perseus (L) 15,000 ~23.53 235,294 ⮟ 13.27% less decay
Moonshine (L) 15,400 ~23.64 236,407 ⮟ 13.67% less decay

Key Insight: Limited armors with high durability (13k+) have significantly better economy than unlimited armors.


Calculation Examples

Example 1: Ghost Armor (2000 durability)

Monster hits for 15 Impact, armor absorbs all 15:

Decay = 15 * 0.05 * (1 - 2000/100000)
Decay = 15 * 0.05 * 0.98
Decay = 0.735 PEC
Decay = 0.00735 PED

Example 2: Angel Armor (4000 durability)

Same 15 Impact hit:

Decay = 15 * 0.05 * (1 - 4000/100000)
Decay = 15 * 0.05 * 0.96
Decay = 0.72 PEC
Decay = 0.0072 PED

Savings: 0.015 PEC (2% less decay than Ghost)

Example 3: Martial (L) (13000 durability)

Same 15 Impact hit:

Decay = 15 * 0.05 * (1 - 13000/100000)
Decay = 15 * 0.05 * 0.87
Decay = 0.6525 PEC
Decay = 0.006525 PED

Savings: 0.0825 PEC (11.22% less decay than Ghost)


Implementation for Lemontropia Suite

Python Implementation:

from decimal import Decimal

def calculate_armor_decay(damage_absorbed: Decimal, durability: int) -> Decimal:
    """Calculate armor decay in PED.
    
    Args:
        damage_absorbed: Amount of damage absorbed by armor
        durability: Armor durability stat
        
    Returns:
        Decay cost in PED
    """
    durability_factor = Decimal(1) - Decimal(durability) / Decimal(100000)
    decay_pec = damage_absorbed * Decimal("0.05") * durability_factor
    return decay_pec / Decimal(100)  # Convert PEC to PED

# Example usage
decay = calculate_armor_decay(Decimal("15"), 2000)  # Ghost absorbing 15 dmg
print(f"Decay: {decay:.5f} PED")  # 0.00735 PED

Armor Stats Database:

ARMOR_DURABILITY = {
    "Ghost": 2000,
    "Gremlin": 2950,
    "Adjusted Nemesis": 3400,
    "Angel": 4000,
    "Martial (L)": 13000,
    "Mayhem (L)": 13300,
    "Angel (L)": 14000,
    "Perseus (L)": 15000,
    "Moonshine (L)": 15400,
}

Plate Decay Formula

Note: Plate decay uses the same formula with plate's own durability.

Plate Decay = damage_absorbed_by_plate * 0.05 * (1 - plate_durability/100000)

Important: Plate and armor decay are calculated independently based on how much damage each absorbed.


Research Notes

  1. Formula confirmed by Hijacker27 and guide author through independent testing
  2. Limited armors >10k durability may use different formula (needs more research)
  3. Decay is linear per damage point absorbed (post-Loot 2.0)
  4. No minimum decay - always proportional to damage absorbed

References

  • PlanetCalypsoForum: "A Most Complete Guide to Armors (2020 Edition)"
  • Hijacker27's research on armor decay
  • VU 15.15 patch notes (Loot 2.0 armor changes)