Expiration rate

The expiration rate of a temporary effect describes how fast or slow time progresses for that effect relative to real time.

Ordinarily, the expiration rate of a temporary effect is equivalent to real time – that is, one second of temporary effect duration lasts one actual second – however, there are modifiers that can increase or decrease it. Modifiers that cause a temporary effect to expire x% slower decrease the expiration rate of that effect, thereby making it last longer. Similarly, modifiers that cause it to expire x% more quickly (or expire x% faster) increase its expiration rate, making it last a shorter period of time.

Mechanics

Despite changing the total time that temporary effects last, it does not increase or decrease the duration of that temporary effect. For most characters this difference does not matter, because the main goal is an overall longer or shorter time for the game mechanic. The difference only matters for benefits and/or downsides that only affect expiration rate or duration. For example:

Vaal skills with duration buffs/auras, like Vaal Molten ShellVaal Molten ShellSpell, AoE, Duration, Fire, Physical, Vaal, Guard
Level: (1-20)
Cooldown Time: 0.50 sec
Can Store 1 Use(s)
Souls Per Use: 50
Can Store 1 Use(s)
Soul Gain Prevention: 14 sec
Cast Time: InstantRequires Level 4Applies a buff that raises your armour, and takes some of the damage from hits for you before being depleted. Each second, the skill deals reflected damage to surrounding enemies based on the damage taken by the buff in that second. When the buff is removed, the skill deals reflected damage to enemies around you based on the total damage that was taken by the buff. You cannot have the buff at the same time as any other Guard skill.Base duration is 9.00 seconds
Modifiers to Skill Effect Duration also apply to this Skill's Soul Gain Prevention
Buff grants +(50-858) to Armour
(35-39)% of Damage from Hits is taken from the Buff before your Life or Energy Shield
Buff can take Damage equal to 20% of your Armour, up to a maximum of 10000
Reflects (300-9000)% of Damage taken from Buff as Fire Damage each second,
or when Buff expires or is depleted

Additional Effects From 1-20% Quality:
(1-20)% increased Skill Effect DurationCorruptedPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. and Vaal GraceVaal GraceAura, Spell, AoE, Duration, Vaal
Level: (1-20)
Cooldown Time: 0.50 sec
Can Store 1 Use(s)
Souls Per Use: 50
Can Store 1 Use(s)
Soul Gain Prevention: 9 sec
Cast Time: Instant
AoE Radius: 36Requires Level 24Casts a temporary aura that grants you and your allies additional chance to evade attacks, and makes suppressed spell damage unlucky against you.Base duration is 6.00 seconds
Modifiers to Buff Duration also apply to this Skill's Soul Gain Prevention
+(0-1.9) metres to radius
You and nearby allies have +15% chance to Evade Attack Hits
Suppressed Spell Damage dealt to you is Unlucky

Additional Effects From 1-20% Quality:
(2-40)% increased Area of EffectCorruptedPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket. will gain soul gain prevention time from Increased Duration modifiers, but not from those that affect expiration rate. Therefore having these skills expire slower on you will result in them being active more often than increased duration would.

Temporary effects that can possibly be affected by expiration rate include buffs, debuffs, curses, flask effects, and temporary auras. Temporary effects that are not affected by expiration rate include rage and Focus, which don't have a modifiable duration, but instead apply at fixed rates or for fixed intervals.

Slower expiry rate is capped at 75% after combining all sources, or a 4x effective duration.^[1]

Formulas

The modifier expire x% faster has diminishing returns, while the modifier expire x% slower has increasing returns.

Expiration Rate

The expiration rate of an effect, where IncreasedExpirationRate and DecreasedExpirationRate are the sums of all expire #% faster and expire #% slower modifiers applicable.

$\color [rgb]{0.6392156862745098,0.5529411764705883,0.42745098039215684}{\text{ExpirationRate}}=1+{\frac {\text{IncreasedExpirationRate}}{100}}-{\frac {\text{DecreasedExpirationRate}}{100}}$

Effective Duration

From its base duration and expiration rate, we can calculate the effective duration of an effect.

$\color [rgb]{0.6392156862745098,0.5529411764705883,0.42745098039215684}{\text{EffectiveDuration}}={\frac {\text{BaseDuration}}{\text{ExpirationRate}}}$

Sources of expiration rate

Gems

Temporal ChainsTemporal ChainsSpell, AoE, Duration, Curse, Hex
Level: (1-20)
Cost: (16-33) Mana
Cast Time: 0.50 secRequires Level 24Curses all enemies in an area, lowering their action speed and making other effects on them expire more slowly.Base duration is (5.00-8.80) seconds
+(0-1) metre to radius
50% less Effect of Curse against Players
Cursed Normal and Magic Enemies have (15-29)% less Action Speed
Other effects on Cursed enemies expire 25% slower
Cursed Rare and Unique Enemies have (9-18)% less Action Speed

Additional Effects From 1-20% Quality:
(1-20)% increased Curse DurationPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.

Temporal RiftTemporal RiftSpell
Level: (1-20)
Reservation: 10% Mana
Cooldown Time: 5.00 sec
Can Store 1 Use(s)
Cast Time: 0.25 secRequires Level 34Reserves mana to apply a buff and leave afterimages of your recent past. Cast the spell again to return to the oldest afterimage, teleporting to that location as well as resetting your Life, Mana and Energy Shield to the values they had then.(0-38)% increased Cooldown Recovery Rate
Buff makes you Unaffected by Temporal Chains
This Spell's Cast Speed cannot be modified

Additional Effects From 1-20% Quality:
Buff causes Debuffs on you to expire (1-20)% fasterPlace into an item socket of the right colour to gain this skill. Right click to remove from a socket.

Buffs

Shaper's Presence

Ultimatum league introduced a trials of chaos. These trials can have an option that makes buffs expire three times faster. This does not affect all temporary effects listed above, only buffs.

Debuffs

Rupture

Notables

Masteries

Duration Mastery

Pantheon

Pantheon Upgrade for Soul of Arakaali: Arachnoxia found in the Toxic Sewer Map

Items

Stasis PrisonStasis Prison
Carnal ArmourEvasion: (847-1008)
Energy Shield: (247-293)
Movement Speed: -3%Requires Level 71, 88 Dex, 122 Int+(20-25) to maximum Mana(140-160)% increased Evasion and Energy Shield
+(80-100) to maximum Life
Temporal Rift has no Reservation
(80-100)% of Damage taken Recouped as Life
Debuffs on you expire (80-100)% fasterThose that can never die have but one wish.
Watcher's EyeWatcher's Eye
Prismatic JewelLimited to: 1(4-6)% increased maximum Energy Shield
(4-6)% increased maximum Life
(4-6)% increased maximum Mana
<Two or Three random aura modifiers>One by one, they stood their ground against a creature
they had no hope of understanding, let alone defeating,
and one by one, they became a part of it.Place into an allocated Jewel Socket on the Passive Skill Tree. Right click to remove from the Socket. grants Debuffs on you expire (20-15)% faster while affected by HasteHasteDebuffsExpireFaster
Intrinsic
Debuffs on you expire (20-15)% faster while affected by Haste
The Flow UntetheredThe Flow Untethered
Cloth BeltRequires Level 60(15-25)% increased Stun and Block RecoveryGrants Summon Harbinger of Time Skill
(10-15)% increased Attack and Cast Speed
(10-15)% increased Energy Shield Recovery rate
(10-15)% increased Life Recovery rate
(15-20)% increased Cooldown Recovery Rate
Debuffs on you expire (15-20)% faster

, The Torrent's ReclamationThe Torrent's Reclamation
Cloth BeltRequires Level 60(15-25)% increased Stun and Block RecoveryGrants Summon Greater Harbinger of Time Skill
(10-15)% increased Attack and Cast Speed
(10-15)% increased Energy Shield Recovery rate
(10-15)% increased Life Recovery rate
(15-20)% increased Cooldown Recovery Rate
Debuffs on you expire (15-20)% faster
Warped TimepieceWarped Timepiece
Turquoise AmuletRequires Level 50+(16-24) to Dexterity and Intelligence(10-25)% increased Attack Speed
(10-25)% increased Cast Speed
(10-15)% increased Movement Speed
(20-10)% reduced Skill Effect Duration
Debuffs on you expire 100% fasterAs you have lived, so you shall die
forever trying to keep up with me.
Your blood on these hands of mine
forever makes me the public enemy.