Breakpoints & Animations

The Diablo 2 engine runs at 25 Frames per Second (FPS). Every action a character performs requires a specific number of frames to complete. Frames can't be broken down into fractions, therefore you have to reduce the count by a complete Frame to shorten the animation length, leading to the Breakpoints of the animation. We can improve the Cast Rate, Hit Recovery, Block Rate and Attack Rate through their corresponding Affixes on gear or Skill effects. Each of these animations has their own calculation on how to reduce its Frame count, which we go into detail in their respective sections. This leads to a table of numeric values that can be reached for each of them, the so-called "Breakpoints". Due to the complexity of Attack Speed, it is covered in our Attack Speed article.

Class Breakpoints

Cast Rate

Mechanics

• Cast Rate determines how fast the animation for a casting based Skill is.
• Your cast animation can be interrupted by...
  • ... hits that put you into Hit Recovery (see below).
  • ... stuns.
  • ... you blocking.
• The animation is split into 3 sections.
  • Frames before the Skill activation
  • The "Action Flag" - The Frame when the Skill occurs
  • The remaining Frames of the animation, before another action can be taken
• You can speed up the animation by using gear with +xx% Faster Cast Rate (FCR).
  • Effective Faster Cast Rate is capped to 75%. As a result, having more than +200% FCR equipped has no effect at all.

Calculations

Note for the calculations:

• ceil = round up the term that follows
• floor = round down the term that follows

Cast Frames

Action Flags

To calculate the Cast Frame of a Character, we need the following values:

• The total +xx% Faster Cast Rate (FCR) from our gear.
• The "Casting base" of the Character. Check in the table below.
• The "Animation Speed" of the Character. Check in the table below.

With these values, we can go through the following formulas.

Effective Faster Cast Rate (EFCR)

Note: EFCR has a hard-coded cap of 75%. This means that FCR values past 200% have no effect.
EFCR = floor(FCR * 120 / (FCR + 120))

Cast Frames

Cast Frames = ceil(256 * Casting Base / floor(Animation Speed * (100 + EFCR) / 100) - 1)

Cast Frame Exception

The Skills Lightning and Chain Lightning of the Sorceress use a slightly modified version of this formula.
Cast Frames = ceil(256 * Casting Base / floor(Animation Speed * (100 + EFCR) / 100))

Character	Casting Base	Animation Speed
Amazon	20	256
Assassin	17	256
Barbarian	14	256
Druid	16	208
Werewolf	16	229
Werebear	16	228
Necromancer	15	256
Vampire form	15	160
Paladin	16	256
Sorceress	14	256
Lightning / Chain Lightning	19	256
Act 3 Mercenary	18	256

Practical Example

Example 1

With 50 FCR on a Sorceress:

Effective Faster Cast Rate (EFCR)

EFCR = floor(50 * 120 / (50 + 120))
EFCR = floor(6,000 / 170)
EFCR = floor(35.294...)
EFCR = 35

Cast Frames

Cast Frames = ceil(3,584 / floor(256 * 135 / 100) -1)
Cast Frames = ceil(3,584/ 345 - 1)
Cast Frames = ceil(9.388...)
Cast Frames = 10

This means the Sorceress with 50 FCR on gear uses 10 Frames for the Cast animation.

Example 2

With 50 FCR on a Sorceress using Lightning:

Effective Faster Cast Rate (EFCR)

EFCR = floor(50 * 120 / (50 + 120))
EFCR = floor(6,000 / 170)
EFCR = floor(35.294...)
EFCR = 35

Cast Frames

Cast Frames = ceil(256 * 19 / floor(256 * (100 + 35) / 100))
Cast Frames = ceil(4,864 / floor(256 * 135 / 100))
Cast Frames = ceil(4,864/ 345)
Cast Frames = ceil(14.098...)
Cast Frames = 15

This means a Sorceress with 50 FCR on gear will use 15 Frames to cast Lightning.

To calculate the Action Flag of a Character, we need the following values:

• The total +xx% Faster Cast Rate from our gear.
• The "Action Flag Base" of the Character. Check in the table below.
• The "Animation Speed" of the Character. Check in the table below.

With these values, we can go through the following formulas.

Effective Faster Cast Rate (EFCR)

Note: EFCR has a hard-coded cap of 75%. This means that FCR values past 200% have no effect.
EFCR = floor(FCR * 120 / (FCR + 120))

Action Flag

Action Flag = ceil(Base Action Flag * 256 / floor(Animation Speed x (100 + EFCR) / 100))

Character	Variable	Animation Speed	Base Action Flag
Amazon	Using Bow	256	10
	No Weapon	256	11
	Using Crossbow / Two-Handed Sword	256	12
	Using Two-handed Staves, Hammers, Axes, Polearms, Knives, Javelins, or Spears	256	13
Assassin	------	256	9
Barbarian	------	256	9
Druid	Normal Form	208	10
	Werewolf	229	8
	Werebear	228	9
Necromancer	Normal Form	256	8
	Vampire Form	160	5
Paladin	------	256	9
Sorceress	------	256	7
Act 3 Mercenary	------	256	7

Practical Example

Practical Example with 70 FCR on am Amazon using a Bow:

Effective Faster Cast Rate (EFCR)

EFCR = floor(FCR * 120 / (FCR + 120))
EFCR = floor(70 * 120 / (70 + 120))
EFCR = floor(8,400 / 190)
EFCR = floor(44.210...)
EFCR = 44

Action Flag

Action Flag = ceil(Base Action Flag * 256 / floor(256 * (100 + EFCR) / 100))
Action Flag = ceil(10 * 256 / floor(256 * (100 + 44) / 100))
Action Flag = ceil(2,560 / floor(256 * 144 / 100))
Action Flag = ceil(2,560 / floor(368.64)
Action Flag = ceil(2,560 / 368)
Action Flag = ceil(6.9565...)
Action Flag = 7

This means any casting Skill of the Amazon using a Bow at 70 FCR will trigger 7 Frames into the animation.

Cast Delay

Skills with a Cast Delay (CD or Cooldown) cause a waiting period before they can be cast again. This period starts at the Action Flag. Cast Delay Skills don't hinder each other to be cast without a waiting period.
The CD itself can't be reduced by any means, however, due to the interaction with the Action Flag, you can reduce the interval (Action Flag + Delay) by hitting Breakpoints for the Action Flag.

Cast Delay Skills

Amazon

Skill	Delay (seconds)
Poison Javelin	0.6
Plague Javelin	4
Immolation Arrow	1
Valkyrie	6

Assassin

Skill	Delay (seconds)
Shock Web	0.6
Blade Sentinel	2
Shadow Warrior	6
Dragon Flight	1
Shadow Master	6

Druid

Skills	Delay (seconds)
Werewolf	1
Firestorm	0.6
Werebear	1
Molten Boulder	2
Fissure	2
Volcano	4
Armageddon	6
Hurricane	6

Paladin

Skill	Delay (seconds)
Fist of the Heavens	1

Sorceress

Skill	Delay (seconds)
Fire Wall	1.4
Meteor	1.2
Blizzard	1.8
Hydra	1.6
Frozen Orb	1

Hit Recovery

Mechanics

• Hit Recovery will interrupt other animations like, cast animation, attack animation, run/walk animation, or your idle animation (standing around).
• While in Hit Recovery, you are unable to perform any actions.
• You can be put into Hit Recovery repeatedly without cooldown, potentially leading to a full "stun lock".
• You can improve the animation by using gear with +xx% Faster Hit Recovery (FHR).

Calculations

Breakpoint Calculations

How is Hit Recovery determined?

Note for the calculations:

• ceil = round up the term that follows
• floor = round down the term that follows

Before we can use the formulas for Hit Recovery, we need the following values:

• The total +xx% Faster Hit Recovery from our gear.
• The "Hit base" of the Character. Check in the table below.
• The "Animation Speed" of the Character. Check in the table below.

With these values, we can go through the following formulas.

Effective Faster Hit Recovery (EFHR)

EFHR = floor(FHR * 120 / (FHR + 120))

Hit Recovery Frames

Hit Recovery Frames = ceil(256 * Hit Base / floor(Animation Speed * (50 + EFHR) / 100) - 1)

Character	Hit Base	Animation Speed
Amazon	6	256
Assassin	5	256
Barbarian	5	256
Druid (1-handed swinging Weapons) (*)	7	248
Druid (Other Weapons)	7	256
Werewolf	4	256
Werebear	5	184
Necromancer	7	256
Vampire Form	4	136
Paladin (Spears and Staves)	5	192
Paladin (Other Weapons)	5	256
Sorceress	8	256
Act 1 Mercenary	6	256
Act 2 Mercenary	8	256
Act 3 Mercenary	9	256
Act 5 Mercenary	5	256

(*) This only means: 1-handed Axes, Clubs, Maces, Scepters, Swords, Throwing Axes, and Wands.

Practical Example

Practical example with 50 FHR on a Sorceress:

Effective Faster Hit Recovery (EFHR)

EFHR = floor(50 * 120 / (50 + 120))
EFHR = floor(6,000 / 170)
EFHR = floor(35.294...)
EFHR = 35

Hit Recovery Frames

Hit Recovery Frames = ceil(256 * 8 / floor(256 * (50 + 35) / 100) - 1)
Hit Recovery Frames = ceil(2,048 / floor(256 * 85 / 100) -1)
Hit Recovery Frames = ceil(2,048 / 217 - 1)
Hit Recovery Frames = ceil(8.437...)
Hit Recovery Frames = 9

This means the Sorceress with 50 FHR on gear will use 9 Frames for the Hit Recovery animation.

The engine goes through a number of steps to determine whether a target is put into Hit Recovery:

• Damage is calculated and applied. The target isn't put into Hit Recovery if
  • the calculated damage is enough to kill the target.
  • the target is Frozen.
  • the applied damage is Poison Damage only.
  • the applied damage is less than 1.
• Check the maximum Life of the target.
• Get the "divisor" value which is needed in the next step. This value is determined by the "hitclass" of the attack, which can be found in the Missile.txt game file. Each attack in the game has a hitclass value attached to it, which translates to a certain divisor. This correlation is hard coded in the engine.

Hitclasses	Divisor
2, 6, 10 and 11	8
Default	16
4 and 8	32
5	64

• Use formula: TriggerNumber = maximum Life / divisor
• Now we actually determine whether the target will be put into Hit Recovery. To do so, the engine goes through the following checks:
  • Compare the value of applied damage with the calculated value for TriggerNumber
    • Damage < TriggerNumber -> No Hit Recovery occurs
    • Damage >= TriggerNumber -> continue with the next check.
  • If Damage is < 2 * TriggerNumber, there is a 50% chance for the target to be put into Hit Recovery. The game rolls a number (rnd{0, 1}).
    • 0 = No Hit Recovery occurs
    • 1 = continue with the next check.
  • If the last check was successful and damage < 4 * TriggerNumber there is a 75% chance for Hit Recovery to occur. The game rolls a number (rnd{0, 1, 2, 3})
    • 0 = No Hit Recovery occurs
    • 1, 2, 3 = Hit Recovery occurs
  • If the applied damage > 4 * TriggerNumber, Hit Recovery occurs guaranteed.
• The final step of the game is to check whether a target can be put into Hit Recovery in the first place. There are a number of targets that are "immune" to Hit Recovery. Your poor CPU might have wasted its time...

Practical Example

Alright... after that mind bender of theory... Let's apply our knowledge to a practical example:
Our Character has 1600 Life and gets hit for 200 damage by an attack with the default divisor of 16.

The first step after knowing these values is:
TriggerNumber = maximum Life / divisor
TriggerNumber = 1600 / 16 = 100

Let's see if we will be put into Hit Recovery:

• 100 < 200 -> Our TriggerNumber is smaller than the inflicted damage. -> go to the next step.
• 100 * 2 = 200 -> The damage is equal to 2 times TriggerNumber. -> Time to roll a random number (rnd{0, 1}), meaning we have a 50% chance to get out of the Hit Recovery check.
  • 0 = No Hit Recovery
  • 1 = Go to next check
• Assuming we got unlucky and rolled a 1 we now have a 75% chance to be put into Hit Recovery. Time to roll another random number to determine that: (rnd{0, 1, 2, 3})
  • 0 = No Hit Recovery occurs
  • 1, 2, 3 = Hit Recovery occurs
• Since the damage is not >= 4x TriggerNumber there is no guarantee to be put into Hit Recovery.
• Finally, let's check whether we can be put into Hit Recovery in the first place. The Characters you play can always be put into Hit Recovery, so if we rolled a 1-3 in the earlier check, we are out of luck and will be put into Hit Recovery.

Block Rate

Mechanics

• Blocking is an animation that is performed when you successfully block a physical attack. This includes the Assassins' Weapon Block.
• While blocking, you are unable to perform any actions.
• You can block repeatedly without cooldown, potentially leading to a full "block lock".
• You can speed up the animation by using gear with +xx% Faster Block Rate (FBR).
  • This Affix is exclusive to Shields, making it very hard to come by. The only exceptions to this rule are Guardian Angel and Pattern.

Calculations

Note for the calculations:

• ceil = round up the term that follows
• floor = round down the term that follows

Before we can use the formulas for Block Rate, we need the following values:

• The total +xx% Faster Block Rate from our gear.
• The "Block Base" of the Character. Check in the table below.
• The "Animation Speed" of the Character. Check in the table below.

With these values, we can go through the following formulas.

Effective Faster Block Rate (EFBR)

EFBR = floor(FBR * 120 / (FBR + 120))

With Holy Shield

EFBR = floor(FBR * 120 / (FBR + 120)) + 50

Block Frames

Block Frames = ceil(256 * Block Base / floor(Animation Speed * (50 + EFBR) / 100) - 1)

Character	Block Base	Animation Speed
Amazon	3	256
Amazon (1-handed Weapons) (*)	3	88
Assassin	3	256
Barbarian	4	256
Druid	6	256
Werewolf	5	256
Werebear	5	200
Necromancer	6	256
Paladin	3	256
Sorceress	5	256

(*) This only means: 1-handed Axes, Clubs, Maces, Hammers, Scepters, Swords, Throwing Axes.

Practical Example

Example 1

With 50 FBR on a Paladin without Holy Shield:

Effective Faster Block Rate (EFBR)

EFHR = floor(50 * 120 / (50 + 120))
EFHR = floor(6,000 / 170)
EFHR = floor(35.294...)
EFHR = 35

Block Frames

Block Frames = ceil(256 * 3 / floor(256 * (50 + 35) / 100) - 1)
Block Frames = ceil(768 / floor(256 * 85 / 100) -1)
Block Frames = ceil(768 / 217 - 1)
Block Frames = ceil(2.539...)
Block Frames = 3

This means the Paladin with 50 FBR and without Holy Shield will use 3 Frames for the Block animation.

Example 2

Practical example with 50 FHR on a Paladin with Holy Shield:

Effective Faster Block Rate (EFBR)

EFHR = floor(50 * 120 / (50 + 120)) + 50
EFHR = floor(6,000 / 170) + 50
EFHR = floor(35.294...) + 50
EFHR = 85

Block Frames

Block Frames = ceil(256 * 3 / floor(256 * (50 + 85) / 100) - 1)
Block Frames = ceil(768 / floor(256 * 135 / 100) -1)
Block Frames = ceil(768 / 345 - 1)
Block Frames = ceil(1.226...)
Block Frames = 2

This means the Paladin with 50 FBR and with Holy Shield will use 2 Frames for the Block animation.

Summary

• Animations are an integral part of your Character's power and survival.
• The information accessible in-game is limited to summing up the animation improving Affixes without telling you whether you actually hit a Breakpoint.
• With every Breakpoint, you reduce the corresponding animation by 1 Frame or 0.04 seconds.

Credits

Written by Teo1904
Reviewed by MacroBioBoi