Slow

A slow is a type of status effect that reduces the afflicted units movement speed by a percentage, and/or attack speed by a flat value of their current speeds.

Mechanics

Usually, slows from different sources stack with each other, but multiple of the same instance do not, but refresh their duration instead. There are some exceptions to this.

Slowing movement speed

Movement speed slows are always percentage based. The percentage of multiple slow instances fully stack, following this movement speed formula. A unit's movement speed cannot be slowed below 100, as it is the minimum allowed movement speed. The only exception are some trap abilities, which set affected units' movement speed to 0. Although roots disallow movement, they technically do not slow and thus have no influences on abilities which work with movement speed. Hexes do not slow either, but rather set a unit's base movement speed to a certain value.

A unit affected by haste fully ignores movement speed slows.

Slowing attack speed

Attack speed slows stack additively as well, but unlike movement speed, do not reduce attack speed by a percentage, but by a flat value. A unit's attack speed cannot be slowed below 20 (every unit's base attack speed is 100, except Roshan who starts with 200). There are no exceptions to this. Disarms do not slow attack speed, but simply do not allow affected units from attacking at all, so their attack speed value is unaffected.

There is no equivalent to haste for attack speed, although some abilities give an enormously high attack speed bonus, so that it is impossible to reduce their attack speed in a regular game.

Movement speed slows

Source	Slow	Duration
Abaddon – Curse of Avernus	8%/12%/16%/20%	2.5
Ancient Apparition – Ice Vortex	15%/20%/25%/30%	16
Ancient Apparition – Chilling Touch	30%	0.3
Ancient Thunderhide – Slam	25%	2 (4 on creeps)
Arc Warden – Flux	20%/30%/40%/50%	6
Arc Warden – Spark Wraith	100%	0.4/0.5/0.6/0.7
Axe – Battle Hunger	12%	10
Batrider – Sticky Napalm	3%/5%/7%/9% per stack	8
Beastmaster – Primal Roar	50%	2/3/4
Boar – Poison	10%/20%/30%/40%	3
Bounty Hunter – Jinada	15%/20%/25%/30%	3
Brewmaster – Thunder Clap	25%/35%/45%/55%	4 (8 on creeps)
Brewmaster – Drunken Haze	10%/20%/30%/40%	4
Bristleback – Viscous Nasal Goo	20% + 3%/6%/9%/12% per stack	5 (10 on creeps)
Broodmother – Incapacitating Bite	16%/26%/36%/46%	2
Centaur Warrunner – Stampede	100%	1.8
Chen – Penitence	18%/24%/30%/36%	8
Crystal Maiden – Crystal Nova	20%/30%/40%/50%	4.5
Crystal Maiden – Freezing Field	30%	10
Dark Seer – Wall of Replica	75%	1
Dazzle – Poison Touch	33%–66%/100%/66%	3/3/3/2
Death Prophet – Spirit Siphon	5%/10%/15%/20%	6
Diffusal Blade – Inhibit	100%–20%	4
Dragon Knight – Elder Dragon Form (Frost Breath)	30%	3
Drow Ranger – Frost Arrows	16%/32%/48%/64%	1.5 (7 on creeps)
Dust of Appearance – Reveal	20% (invisible units only)	12
Earth Spirit – Rolling Boulder	80% (only when using a Stone Remnant)	0.8/1.2/1.6/2
Echo Sabre – Echo Strike	100%	0.6
Elder Titan – Earth Splitter	30/40/50%	3/4/5 ( 4/5/6)
Enchantress – Enchant	55%	3/4/5/6
Ethereal Blade – Ether Blast	80%	3
Eye of Skadi – Cold Attack	35%	5/2.5 (melee/ranged)
Faceless Void – Time Dilation	10% (for each cooldown frozen)	6/8/10/12
Ghost – Frost Attack	20%	1.5
Gyrocopter – Call Down	30%/60% (first/second missile)	2/4 (first/second missile)
Heaven's Halberd – Maim	26%/13% (melee/ranged)	5
Hellbear Smasher – Thunder Clap	25%	3
Huskar – Life Break	40%/50%/60%	4/5/6
Invoker – Ghost Walk	20%/25%/30%/35%/40%/45%/50% ( /55%), 30%/20%/10% self-slow on levels 1–3	100
Invoker – Ice Wall	20%/40%/60%/80%/100%/120%/140% ( /160%)	3/4.5/6/7.5/9/10.5/12 ( /13.5)
Io – Spirits	20%/40%/60%/80%	0.3
Jakiro – Dual Breath	28%/32%/36%/40%	5
Kunkka – Torrent	35%	3.35/4.1/4.85/5.6 (applied together with a stun)
Leshrac – Lightning Storm	75%	0.4/0.6/0.8/1 ( 3.4/3.6/3.8/4)
Lich – Frost Blast	30%	4
Lich – Ice Armor	30%	2
Lich – Chain Frost	50%	2.5
Lich – Freezing Slow	40%	3
Lifestealer – Open Wounds	70%–10%	8
Lion – Mana Drain	16%/19%/22%/25%	5
Magnus – Skewer	25%/30%/35%/40%	2.5/2.75/3/3.25
Medusa – Stone Gaze	35%	5/6/7
Meepo – Geostrike	5%/10%/15%/20%	2
Monkey King – Primal Spring	0%–20%/40%/60%/80%	4
Necrophos – Ghost Shroud	6%/12%/18%/24% ( 22%/28%/34%/40%)	3/3.5/4/4.5
Night Stalker – Void	50%	2 (day), 2.5/3/3.5/4 (night)
Nullifier – Nullify	100%	0.4
Ogre Frostmage – Ice Armor	30% (melee units only)	5
Ogre Magi – Ignite	20%/22%/24%/26%	5/6/7/8
Omniknight – Degen Aura	10%/18%/26%/34% ( 26%/34%/42%/50%)	Indefinite
Orb of Venom – Poison Attack	12%/4% (melee/ranged)	3
Pangolier – Heartpiercer	35%/40%/45%/50%	2/3/4/5
Phantom Assassin – Stifling Dagger	50%	1/2/3/4
Phantom Lancer – Spirit Lance	10%/20%/30%/40%	3.25
Phoenix – Icarus Dive	28%	4
Pudge – Rot	17%/22%/27%/32%	Indefinite
Pugna – Decrepify	30%/40%/50%/60%	3.5
Queen of Pain – Shadow Strike	20%/30%/40%/50%–0%	15
Razor – Unstable Current	100%	0.5/1/1.5/2
Riki – Smoke Screen	10%/15%/20%/25%	6
Roshan – Slam	50%	2 (4 on creeps)
Sand King – Caustic Finale	21/24/27/30%	3
Sand King – Epicenter	30%	3
Sange – Maim	26%/13% (melee/ranged)	5
Sange and Yasha – Maim	26%/13% (melee/ranged)	5
Satyr Banisher – Purge	50%–10%	5
Shadow Demon – Demonic Purge	100%–20%	7
Shadow Fiend – Requiem of Souls	25%	5
Shiva's Guard – Arctic Blast	40%	4
Silencer – Arcane Curse	9%/12%/15%/18% ( 34%/37%/40%/43%)	6 + 4 per spell cast
Skywrath Mage – Concussive Shot	30%/35%/40%/45%	4
Slardar – Slithereen Crush	20%	3.5/3.75/4/4.25 (applied together with a stun)
Sniper – Shrapnel	15%/20%/25%/30%	10
Sniper – Headshot	100%	0.5
Spectre – Spectral Dagger	8%/12%/16%/20%	12
Spiderling – Poison Sting	8%	2 (6 on creeps)
Storm Spirit – Electric Vortex	50%	3
Storm Spirit – Overload	80%	0.6
Templar Assassin – Psionic Trap	30%–60%	5
Terrorblade – Reflection	25%	2.5/3.5/4.5/5.5
Tidehunter – Gush	40%	4
Timbersaw – Chakram	5% (for every 5% of health missing)	Indefinite
Timbersaw – Chakram (Aghanim's Scepter)	5% (for every 5% of health missing)	Indefinite
Tornado – Tempest	15%	40
Treant Protector – Leech Seed	16%/20%/24%/28%	4.5
Troll Warlord – Whirling Axes (Ranged)	30%	3/3.75/4.5/5.25
Tusk – Frozen Sigil	10%/15%/20%/25%	30
Tusk – Walrus PUNCH!	40%	3/4/5
Tusk – Walrus Kick	40%	5
Undying – Flesh Golem	1%–20%	30
Undying Zombie – Deathlust	7%	2.5
Ursa – Earthshock	25%/35%/45%/55%	4
Venomancer – Venomous Gale	50%–0%	15
Venomancer – Poison Sting	11%/12%/13%/14%	6/9/12/15
Viper – Poison Attack	10%/20%/30%/40%	2
Viper – Corrosive Skin	10%/15%/20%/25%	4
Viper – Viper Strike	40%/60%/80%–0%	5.1
Visage – Grave Chill	32%	3/4/5/6
Warlock – Upheaval	7%/14%/21%/28% per second channeled, max of 84%	16
Windranger – Windrun	8%/16%/24%/30% ( 33%/41%/49%/55%)	3/4/5/6
Winter Wyvern – Arctic Burn	22%/28%/34%/40% ( 37%/43%/49%/55%)	5
Winter Wyvern – Splinter Blast	30%	4
Wraith King – Wraithfire Blast	20%	4 (applied together with a stun)
Wraith King – Reincarnation	75%	5

Attack speed slows

Source	Slow	Duration	Max Attacks Reduction	Note
Abaddon – Curse of Avernus	8/12/16/20	2.5	0.125/0.25/0.375/0.5	Also affects attacked buildings, but not wards.
Beastmaster – Primal Roar	50	2/3/4	1/1.5/2	Affects secondary targets.
Boar – Poison	10/20/30/40	3	0.3/0.6/0.9/1.2
Bounty Hunter – Jinada	15/20/25/30	3	0.45/0.6/0.75/0.9
Brewmaster – Thunder Clap	25/35/45/55	4 ( 7)	1/1.4/1.8/2.2	Hero duration.
Brewmaster – Thunder Clap	25/35/45/55	8 ( 11)	2/2.8/3.6/4.4	Creep duration.
Crystal Maiden – Crystal Nova	20/30/40/50	4.5	0.9/1.35/1.8/2.25
Crystal Maiden – Freezing Field	30	1	0.3	Refreshes the slow on enemies within range for up to 10 seconds.
Dragon Knight – Elder Dragon Form	30	3	0.6	Only available on level 3. Attacks slow enemies within a radius.
Enchantress – Untouchable	20/60/100/140 ( 120/160/200/240)	Indefinite	Indefinite
Eye of Skadi – Cold Attack	45	5	2.25	Melee wielder.
Eye of Skadi – Cold Attack	45	2.5	1.125	Ranged wielder.
Ghost – Frost Attack	20	1.5	0.3
Heaven's Halberd – Maim	26/13 (melee/ranged)	5	1.3/0.65	Has a 40% chance to proc on attack targets.
Hellbear Smasher – Thunder Clap	25	3	0.75
Jakiro – Dual Breath	28/32/36/40	5	1.4/1.6/1.8/2
Jakiro – Liquid Fire	30/40/50/60 ( 90/100/110/120)	5	1/1.5/2/2.5	Affects buildings as well.
Lich – Frost Blast	20	4	1.2
Lich – Ice Armor	8/16/24/32	2	0.4	Slows enemies which attack the shielded unit.
Lich – Chain Frost	65	2.5	needs completion
Lich – Freezing Slow	40	3	1.2	Talent learned at level 25.
Lycan Wolf – Cripple	60	4	1.6	20% chance to proc. Multiple instances do not stack.
Magnus – Skewer	25/30/35/40	2.5/2.75/3/3.25	needs completion	Slows affected enemies after the dragging.
Medusa – Stone Gaze	35	5/6/7 ( 7.5/8.5/9.5)	needs completion	May fully disable enemies for 3 seconds when staring too long.
Night Stalker – Void	50	1.25	1	During daytime.
Night Stalker – Void	50	4	2	During nighttime.
Ogre Frostmage – Ice Armor	20	5	1	Slows enemies which attack the shielded unit.
Omniknight – Degen Aura	10/18/26/34 ( 22/30/38/46)	Indefinite	Indefinite	Aura.
Phoenix – Fire Spirits	80/100/120/140	4	3.2/4/4.8/5.6
Roshan – Slam	50	2	1	Hero duration.
Roshan – Slam	50	4	2	Creep duration.
Sand King – Epicenter	30 ( 80)	3	0.9	Releases pulses for 3 seconds, which refresh the slow on nearby enemies.
Sange – Maim	26/13 (melee/ranged)	5	1.3/0.65	Has a 40% chance to proc on attack targets.
Sange and Yasha – Maim	26/13 (melee/ranged)	5	1.3/0.65	Has a 40% chance to proc on attack targets.
Shiva's Guard – Freezing Aura	45	Indefinite	Indefinite	Aura.
Slardar – Slithereen Crush	20	2	0.4
Sniper – Headshot	100	0.5	0.5	Has a 40% chance to proc on attack targets.
Storm Spirit – Overload	50	0.6	0.3
Tiny – Grow	20/35/50	Indefinite	Indefinite	Affects self.
Ancient Thunderhide – Slam	25	2	0.5	Hero duration.
Ancient Thunderhide – Slam	25	4	1	Creep duration.
Tusk – Frozen Sigil	30/40/50/60	Indefinite	Indefinite	Aura. The sigil lasts for up to 30 seconds.
Viper – Poison Attack	25/30/35/40	3	needs completion
Viper – Corrosive Skin	8/16/24/32 ( 14/22/30/38)	4	0.4/0.6/0.8/1	Affects enemies which damage Viper.
Viper – Viper Strike	40/60/80	5	Indefinite	The slow decreases linearly in 0.1 second intervals.
Visage – Grave Chill	64	3.25/4.5/5.75/7	needs completion
Tornado – Tempest	15	Indefinite	Indefinite	Aura. The Tornado lasts for up to 40 seconds.
Wraith King – Reincarnation	75	5	3.75	Slows all nearby enemies when on death when reincarnating.

See also

• Movement speed
• Attack speed
• Disables

Mechanics Stats Armor Attributes (Strength / Agility / Intelligence) Collision size Health (Health regeneration) Magic resistance Mana (Mana regeneration) Movement speed Status resistance Turn rate Vision Attack Attack animation Attack damage Attack modifier (Bash / Cleave & Splash / Critical strike / Lifesteal / Mana break) Attack range Attack speed Cast animation Cast range Damage types Motion buffer range Projectile speed Spell damage Spell lifesteal Abilities Abilities Aura Channeling Damage block Damage manipulation Damage over time Evasion Talents Teleport Status effects Break Cyclone Disable Disarm Ethereal Fear Forced movement Hex Hide Invisibility Invulnerability Root Silence Sleep Slow Spell immunity Stun Taunt World Experience Gold Glyph of Fortification Map (Minimap) River Scan Runes Time of day Trees Gameplay Creep control techniques Denying Disjoint Dispel Ganking Harassment Hero complexity Initiating Item passive stacking Item sharing Jungling Lane Pushing Random distribution Roles Trap Units Ancient creeps Buildings Couriers Creep-heroes Heroes Illusions Lane creeps Neutral creeps Roshan Summons & Wards