Comprehensive Guide to Calculating Damage Numbers in Diablo IV
Understanding how damage is calculated in Diablo IV is essential for optimizing your character’s build and maximizing your effectiveness in combat. The game employs a complex system that combines base damage with various additive and multiplicative bonuses. This guide will walk you through the process step-by-step, providing a clear framework to calculate damage numbers for a single hit. Whether you’re a Barbarian cleaving through enemies or a Sorcerer hurling spells, this breakdown will help you grasp the mechanics behind your damage output.
Overview of Damage Calculation
In Diablo IV, damage is determined by starting with a base damage value, which is then modified by a series of additive bonuses and multiplicative bonuses. These bonuses come from your weapon, skills, attributes, gear affixes, and specific mechanics like critical strikes or vulnerable status. The general formula can be expressed as:
Total Damage = [Base Damage] × [1 + Sum of Additive Damage Bonuses] × [Multiplicative Bonuses]
The multiplicative bonuses typically include factors like your primary attribute, critical strike damage, vulnerable damage, and other global multipliers from unique items or legendary aspects. Below, we’ll break this down into manageable sections.
Step 1: Calculate Base Damage
The foundation of your damage calculation is the base damage, which depends on your weapon and the skill you’re using.
- Weapon Damage: Every weapon in Diablo IV has a damage range (e.g., 50–100 damage). For simplicity, you can use the average weapon damage when calculating. For dual-wielding classes like Barbarians or Rogues, the game typically uses the damage of the specific weapon tied to the skill’s hit. For a general guide, assume we’re calculating for a single hit with one weapon’s average damage.
- Skill Damage Percentage: Each skill has a damage percentage listed in its description (e.g., “Deals 100% weapon damage”). This percentage scales directly with your weapon damage. Even many spells in Diablo IV scale with weapon damage, unlike some other games where they might have independent values.
Formula for Base Damage:
Base Damage = Weapon Damage × Skill Damage %
Example:
- Weapon Damage: 50–100 (average = 75)
- Skill: “Deals 120% weapon damage”
- Base Damage = 75 × 1.2 = 90
Note: The damage shown in skill tooltips may already include some bonuses (like attributes), but for a precise manual calculation, start with weapon damage and skill percentage as the raw base.
Step 2: Apply Additive Damage Bonuses
Next, you add up all additive damage bonuses. These are percentage increases that stack together within the same “damage bucket” and are applied to the base damage. Additive bonuses are common and come from various sources, such as skills, passives, gear affixes, and paragon boards.
Common Sources of Additive Bonuses:
- Skill and Passive Bonuses: e.g., +20% damage with Core Skills
- Enemy-Specific Bonuses: e.g., +15% damage to Elites, +10% damage to Demons
- Conditional Bonuses: e.g., +25% damage to Close Enemies, +30% damage while Healthy
- General Bonuses: e.g., +10% damage from a gear affix
Sum all applicable additive bonuses to get the total additive damage percentage.
Formula:
Additive Damage Multiplier = 1 + Sum of Additive Bonuses
Example:
- +20% damage with Core Skills
- +15% damage to Close Enemies
- +10% damage to Elites
- Total Additive Bonus = 20% + 15% + 10% = 45% = 0.45
- Additive Damage Multiplier = 1 + 0.45 = 1.45
Damage So Far = Base Damage × Additive Damage Multiplier
Using the previous example:
- Base Damage = 90
- Damage with Additive Bonuses = 90 × 1.45 = 130.5
Step 3: Apply Multiplicative Bonuses
After additive bonuses, multiplicative bonuses are applied. These are separate “damage buckets” that multiply the damage further, making them more powerful than additive bonuses. In Diablo IV, the main multiplicative bonuses include the primary attribute, critical strike damage, vulnerable damage, and other global multipliers.
3.1 Primary Attribute Multiplier
Each class has a primary attribute that boosts damage:
- Barbarian: Strength
- Rogue: Dexterity
- Sorcerer: Intelligence
- Necromancer: Intelligence
- Druid: Willpower
- Spiritborn: Resolve
The exact scaling isn’t publicly detailed, but it’s commonly understood that the primary attribute provides a multiplicative bonus. For example, every 10 points of your primary stat might grant +1% damage, though this is an approximation.
Assumed Formula:
Primary Attribute Multiplier = 1 + (Primary Stat × Scaling Factor)
- Scaling Factor might be something like 0.001 (0.1% per point), but let’s assume 1000 Strength = +100% damage (2x) for simplicity.
Example:
- Primary Stat: 1000 Strength
- Multiplier = 1 + (1000 × 0.001) = 1 + 1 = 2
3.2 Critical Strike Multiplier
If the hit is a critical strike (based on your Critical Strike Chance), you apply the critical strike multiplier. The base critical damage is 50% (1.5x), increased by additional critical damage bonuses from gear or skills.
Formula:
Critical Multiplier = 1 + (Base Crit Damage + Additional Crit Damage %)
- Base Crit Damage = 0.5 (50%)
- Additional Crit Damage = e.g., +50% from gear
Example:
- Base Crit Damage = 50%
- +50% Critical Damage Bonus
- Critical Multiplier = 1 + (0.5 + 0.5) = 1 + 1 = 2 (if crit occurs)
If the hit isn’t a crit, this multiplier is 1 (no increase).
3.3 Vulnerable Damage Multiplier
When an enemy is Vulnerable (often triggered by skills or effects), they take increased damage. The base vulnerable bonus is 20% (1.2x), enhanced by additional vulnerable damage bonuses.
Formula:
Vulnerable Multiplier = 1 + (Base Vulnerable Damage + Additional Vulnerable Damage %)
- Base Vulnerable Damage = 0.2 (20%)
- Additional Vulnerable Damage = e.g., +30%
Example:
- Base Vulnerable Damage = 20%
- +30% Vulnerable Damage Bonus
- Vulnerable Multiplier = 1 + (0.2 + 0.3) = 1.5 (if enemy is vulnerable)
If the enemy isn’t vulnerable, this multiplier is 1.
3.4 Other Global Multipliers
Certain legendary aspects, unique items, or skills provide additional multiplicative bonuses (e.g., “x% increased damage”). These are rare but stack multiplicatively with the above.
Example:
- Unique Item: +50% increased damage
- Multiplier = 1 + 0.5 = 1.5
Total Multiplicative Bonus = Primary Attribute Multiplier × Critical Multiplier × Vulnerable Multiplier × Other Multipliers
Final Damage Formula
Putting it all together:
Total Damage = [Base Damage] × [1 + Sum of Additive Bonuses] × [Primary Attribute Multiplier] × [Critical Multiplier (if crit)] × [Vulnerable Multiplier (if vulnerable)] × [Other Global Multipliers]
Full Example:
- Weapon Damage: 75 (average)
- Skill Damage %: 120% (1.2)
- Additive Bonuses: +45% (1.45 multiplier)
- Primary Stat: 1000 Strength (2x multiplier)
- Critical Strike: Yes, with +50% bonus (2x multiplier)
- Vulnerable: Yes, with +30% bonus (1.5x multiplier)
- Other Multipliers: None (1x)
1. Base Damage = 75 × 1.2 = 90
2. With Additive Bonuses = 90 × 1.45 = 130.5
3. Primary Stat = 130.5 × 2 = 261
4. Critical Strike = 261 × 2 = 522
5. Vulnerable = 522 × 1.5 = 783
Total Damage = 783
Additional Considerations
Overpower Mechanic
Overpower is a separate mechanic with a base 3% chance to trigger, adding bonus damage equal to your total Life plus Fortify. This bonus can crit and is added to the total damage but calculated separately. For simplicity, it’s often excluded from per-hit calculations unless focusing on an Overpower build.
Attack Speed and DPS
Attack speed doesn’t affect damage per hit but increases your damage per second (DPS) by allowing more hits over time. To calculate DPS, multiply the damage per hit by your attacks per second.
Damage Variance
Weapon damage ranges mean your actual damage varies slightly per hit. Use average values for consistency.
Enemy Defenses
This guide focuses on your damage output before enemy damage reduction (e.g., armor or resistances), which would lower the final damage taken by enemies.
Summary
To calculate damage numbers in Diablo IV:
- Base Damage: Multiply your weapon’s average damage by the skill’s damage percentage.
- Additive Bonuses: Sum all +% damage bonuses and apply as a single multiplier (1 + total %).
- Multiplicative Bonuses: Apply separate multipliers for primary attribute, critical strikes (if applicable), vulnerable status (if applicable), and other global effects.
- Multiply all components together for the total damage per hit.
By understanding and balancing these “damage buckets,” you can optimize your gear and skills for maximum output.
Happy slaying, Nephalem!
