Tinker
* Skywrath Mage stands perfectly on the center line against Tinker, thanks to his nuke and silence. Also, thanks to his abilities, he can quickly kill a victim, and Tinker is one of the most subtle heroes in the game
Additional:
* Skywrath Mage stands perfectly on the center line against Tinker, thanks to his nuke and silence. Also, thanks to his abilities, he can quickly kill a victim, and Tinker is one of the most subtle heroes in the game
Legion Commander
* 
Mystic Flare can easily burst down Legion Commander while she is Dueling.
Tinker
* 
Nether Ward discourages Tinker from using abilities and items due to its high damage against heavy mana usage.
Legion Commander
* 
Decrepify on either hero stops Legion Commander from completing a Duel, and dissuades her from initiating Duels on ethereal allies.
* 
Life Drain can help Pugna's teammates win a fight, either by killing Legion Commander or replenishing her target's health.
Additional:
* Decrepify prevents Legion Commander from attacking allies during 
Duel, regardless if it's used on her or on the ally .
* Pugna can easily cast Decrepify, Nether Blast and Life Drain on Legion during the 4/4.75/5.5/8 seconds of duel
Tinker
* 
Shadow Wave provides good sustain against Tinker's spammable abilities.
* 
Shallow Grave can stop Tinker from bursting down a target.
Legion Commander
* Shallow Grave prevents Legion Commander from killing her opponents in Duels.
* Shadow Wave will heal an ally caught in a Duel, as well as dealing damage to Legion Commander.
Tinker
* 
Tinker who can't fight multiple heroes will suffer greatly against Ransack and Earthbind.
Legion Commander
* When Legion Commander uses Duel on one Meepo, he can use his other Meepos to kill her. If he wasn't dueled, he can help the teammate who was duelled to give the teammate the damage instead of Legion Commander.
* However, if Legion Commander picked up an Aghanim's Scepter and she duels one Meepo, that might be the end of Meepo if Legion managed to gather enough damage from previous duels.
Tinker
* Zeus can easily reveal Tinker's location in the trees with 
Thundergod's wrath.
* When Zeus has an 
Aghanim's Scepter, he can use his 
Nimbus, together with 
Lightning Bolt to interrupt Tinker's 
Keen Conveyance channelling and cancel Tinker's 
Blink Dagger.
Additional:
* Due to Tinker's low health pool, Zeus can easily burst Tinker down, while also cancelling 
Rearm.
* Once Zeus gets Aghanim's Scepter, he will gain Nimbus, which allows him to scout out Tinker on the map, especially when he is pushing lanes while hiding in the trees.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: 
Nature's Prophet, 
Ancient Apparition, 
Zeus, 
Invoker, 
Treant Protector
Tinker
* Even though Luna has a hard time laning against Tinker because of 
Heat-Seeking Missile and 
Laser, she can win against him in late game once she buys 
Black King Bar, as none of Tinker's spells can bypass spell immunity.
* 
Lucent Beam and 0.25 
Eclipse Lucent Mini-stun talent for Eclipse can be used to cancel Rearm and prevent Tinker's escape attempts with 
Boots of Travel. Luna can also use Lucent Beam and Eclipse if she is blinded with Laser.
* An ill-timed and ill-positioned Blink Dagger will make Tinker a very easy target for Luna's Eclipse that can quickly tear him to shreds. This can get even better if Luna buys Aghanim's Scepter and combines it with 0.25 Eclipse Lucent Mini-stun talent for Eclipse.
* However, Luna needs to approach Tinker carefully, as Tinker is a natural 
Scythe of Vyse wielder, and if he gets a jump on Luna first, he will be able to use it to disable and burst down Luna before she can use Black King Bar, Lucent Beam or Eclipse.
Additional:
* Even though Luna has a hard time laning against Tinker because of Heat-Seeking Missile and Laser, she can win against him in late game once she buys Black King Bar, as none of Tinker's spells can bypass spell immunity.
* Lucent Beam and 0.25 Eclipse Lucent Mini-stun talent for Eclipse can be used to cancel Rearm and prevent Tinker's escape attempts with Boots of Travel. Luna can also use Lucent Beam and Eclipse if she is blinded with Laser.
* An ill-timed and ill-positioned Blink Dagger will make Tinker a very easy target for Luna's Eclipse that can quickly tear him to shreds. This can get even better if Luna buys Aghanim's Scepter and combines it with 0.25 Eclipse Lucent Mini-stun talent for Eclipse.
* However, Luna needs to approach Tinker carefully, as Tinker is a natural Scythe of Vyse wielder, and if he gets a jump on Luna first, he will be able to use it to disable and burst down Luna before she can use Black King Bar, Lucent Beam or Eclipse.
Legion Commander
* A well-timed Eclipse before a Duel usually prevents Legion Commander from winning Duels, if Luna is the target.
* Meanwhile, when Luna is not a target, Eclipse and Lucent Beam can also help an ally win a Duel against Legion Commander.
* However, skilled Legion Commander will always buy a Black King Bar to block Eclipse and Lucent Beam or Aghanim's Scepter to reduce it's damage.
Additional:
* A well-timed Eclipse before a Duel usually prevents Legion Commander from winning Duels if Luna is the target. Luna can also buy 
Linken's Sphere to block Duel.
* Meanwhile, when Luna is not a target, Eclipse and Lucent Beam can also help an ally win a Duel against Legion Commander.
* Bear in mind, however, that skilled Legion Commander will always buy a Black King Bar to block Eclipse and Lucent Beam or Aghanim's Scepter to reduce their damage.
Legion Commander
* Heroes that can keep Luna locked down for a long time can be a threat (she is very item and spell dependent): 
Faceless Void, 
Legion Commander, 
Doom.
Tinker
* Heroes that can gain vision over trees to catch Tinker: Invoker, 
Shadow Demon, 
Batrider.
Legion Commander
* Heroes who can hide the Dueled target (
Outworld Destroyer, Shadow Demon, 
Tusk, 
Phoenix with Aghanim's Scepter etc).
Additional:
* Disruption can save allies and mess up an initiation from an enemy Legion Commander. Using Disruption on your ally that is affected by Duel will leave her totally exposed without the benefit of the life steal from 
Moment of Courage. A precise decision to Disrupt Legion Commander or her victim is crucial to waste Duel's potential.
* Demonic Purge cannot be dispelled by a hard dispel from 
Press the Attack, which in turn can be dispelled by your ultimate.
Legion Commander
* If he isn't broken (break), Abaddon can use Borrowed Time to waste Legion Commander's Duel, As Borrowed Time has a shorter cooldown, Legion Commander can't win duels, effectively reducing her targets by one, Duel also means that Borrowed Time heals Abaddon for the duration of the duel, as Legion can't stop attacking.
Additional:
* 
Aphotic Shield and 
Mist Coil makes it hard for Legion Commander to kill Abaddon's teammates in Duels.
* 
Borrowed Time makes Abaddon nearly impossible to kill in Duels, and often replenishes much of his health because Legion Commander cannot manually stop attacking during Duels.
Legion Commander
* 
Purification prevents Legion Commander from killing her target, and will always hit her during Duels.
* 
Guardian Angel completely wastes Duel's duration and can save an ally across the map when upgraded with Aghanim's Scepter.
Additional:
* Both Guardian Angel and Purification are perfect counters against Duel.
Legion Commander
* 
Mana Shield makes Medusa very hard to take down in Duels.
* 
Stone Gaze stops Legion Commander from Dueling altogether, regardless of who she targets.
Legion Commander
* 
Gravekeeper's Cloak protects Visage from Legion Commander's attacks for most of Duel's duration.
* Chain stuns from Visage's familiars prevents Legion Commander from winning Duels.
Tinker
* Night Stalker is one of the best heroes to find (and silence) Tinker in the trees during Dark Ascension.
Additional:
* Night Stalker can easily find Tinker in the trees during 
Dark Ascension.
* 
Void's mini-stun will stop Rearm and Keen Conveyance
* 
Crippling Fear's silence will prevent Tinker from fighting back, as Tinker relies on his spells.
Tinker
* 
Wave of Terror can reveal a Tinker attempting to hide in the trees and then 
Nether Swap and 
Magic Missile will both serve to interrupt/lock him down, should he attempt to town portal or reload.
Legion Commander
* 
God's Strength makes Sven one of the worst heroes to Duel.
* 
Storm Hammer can be used to interrupt Duels.
* 
Warcry gives a big boost in passive defensive ability with the active component to nearby allies.
* With the Aghanim Shard Warcry also gives nearby allies passive increases.
Tinker
* Lifestealer's Rage makes him immune to all of Tinker's damage and debuffs.
* Lifestealer can infest a mobile ally (teams usually pick one against Tinker), which may ensure that Tinker will die if he is caught.
Additional:
* 
Rage will dispel Laser's blind and turns him spell immune for the duration so Tinker cannot damage him.
* 
Feast will quickly bring down Tinker due to being so fragile.
Legion Commander
* Earthshaker's AoE stuns can save ally against Duel, forcing Legion Commander to spend Aghanim's Scepter or Black King Bar.
Legion Commander
* 
Paralyzing Cask can save ally from Legion Commander Duel's until she purchases Aghanim's Scepter.
* 
Voodoo Restoration can heal Witch Doctor allies from Duel's.
* 
Death Ward can help Witch Doctor allies from winning Duel's, if, he is not a target.
Tinker
* Tinker relies on his high mobility from Boots of Travel and Blink Dagger to survive. Those items don't help him if Spirit Breaker manages to cast Charge of Darkness on him.
* Spirit Breaker can easily cancel Rearm and Boots of Travel.
Legion Commander
* Solar Guardian can save allies who are being dueled and will interrupt her Duel initiation.
Tinker
* 
Pounce prevents Tinker from blinking away.
* Slark frequently builds 
Shadow Blade, which allows him to approach Tinker unnoticed. Since Tinker's farming usually covers a significant amount of area on the map, Sentry Wards may not be cost effective.
* 
Shadow Dance allows Slark to detect both common and unusual wards. Eliminating common ward causes Tinker trouble farming many lanes if he does not know who may be waiting to jump on him. Slark is also uniquely able to identify some of the less common wards used by Tinker, such as those placed on the cliffs at map edges which Tinker uses to give him vision over the trees he uses to hide in.
* Slark's extremely high move speed from Shadow Dance, potentially stacked with Shadow Blade, allows him to easily follow Tinker between lanes, especially if Tinker has pushed the lanes out.
* 
Dark Pact dispels Laser's blind.
Tinker
* Storm Spirit destroys trees and ignores impassable terrains with 
Ball Lightning, rendering them dangerous places for Tinker to hide within.
* Ball Lightning disjoints projectile from Heat-Seeking Missile and damage from 
March of the Machines.
* 
Electric Vortex prevents Tinker from teleporting away, and 
Static Remnant and 
Overload can easily burst him down.
Additional:
* He can easily catch Tinker in the trees with Ball Lightning and kill him with 
Orchid Malevolence and his abilities, which deal both physical and magical damage, making them difficult for Tinker to itemize against.
Legion Commander
* With armor items like 
Solar Crest or 
Assault Cuirass combined with Bash of the Deep, Slardar can easily tank the Duel, If not dueled himself, he can drop Legion Commander's armor during duel and/or buff his teammate and save them, leaving her only the choice of dueling supports which can also be saved with fast Blink into Slithereen Crush.
Tinker
* His global teleportation with Boots of Travel and Rearm is easily countered with 
Haunt, and Spectre can reach him anywhere on the map.
* He is squishy, and if alone 
Desolate will kill him very fast.
* 
Dispersion can reflect and reduce his burst damage.
Tinker
* Illusion heroes, such as 
Naga Siren, 
Phantom Lancer, 
Chaos Knight, 
Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, 
Mjollnir or 
Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Legion Commander
* Song of the Siren lasts long enough to prevent a successful Duel (but only if Naga wasn't the target).
Legion Commander
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Legion Commander
* 
Lucky Shot can disarm Legion Commander and reduce her armor, which can reduce her chances of winning a duel. If an ally is targeted, Pangolier can simply use 
Swashbuckle to inflict it on her.
* If an enemy Pangolier casts a well-timed 
Rolling Thunder before Legion Commander can cast Duel, it might result in her chasing down Pangolier until his or her ultimate ends, whichever duration ends first, resulting in an open window for enemy allies to target Legion Commander, making her vulnerable and susceptible to any source of attacks. If Legion Commander has an Aghanim's Scepter in her inventory, the risk of wasting a solid 8 seconds would result in a futile duel.
* Dueling Pangolier is normally a mistake, Pangolier can disarm you in the duel, and potentially gain some Duel damage, Only duel Pangolier if at least 1 ally is nearby, and he is on low health, And even then, be wary, A good duel can easily turn against you with one Lucky Shot (Due to Lucky Shot lasting 4 seconds).
Additional:
* Swashbuckle can be used to disarm Legion Commander while she is Dueling an ally, granting her opponent a considerable advantage, Lucky Shot lasts 4 seconds at most wasting Legion Commander's entire Duel, (Or half, if Legion Commander has the Scepter).
* Legion Commander will try not to duel Pangolier alone, as she will almost inevitably lose, thanks to Lucky Shot's disarm, If Legion Commander wants to duel a Pangolier, she must be with atleast a teammate, and if she has her scepter, 3 or 4 teammates.
* Legion Commander is often with her allies, allowing you to rack up some considerable damage resistance with Shield Crash.
Tinker
* Tinker is heavily dependent on his abilities and 
Doom prevents him from using any of them.
* This becomes even worse if Doom chooses the level 25 talent {ValueColor:1|Doom applies Mute|25tal} {Symbol:Talent}, which will prevent Tinker from using items such as Blink Dagger.
Additional:
* Tinker is heavily reliant on casting his spells and Doom can disable all of his abilities and items. An Aghanim's Scepter only makes it harder for Tinker to survive.
Tinker
* Beastmaster's Hawk can find Tinker easily while he is pushing or blinking into trees.
Tinker
* Tinker is relatively helpless against Invoker, as his Rearm and Boots of Travel can be easily interrupted by Invoker's long range disables, even if he blinks away.
Legion Commander
* Invoker's spells will disable and destroy Legion Commander while she's locked in a Duel.
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: 
Crystal Maiden, 
Enchantress, 
Gyrocopter, 
Lion, 
Riki, 
Techies, Terrorblade, 
Necrophos, Invoker.
Legion Commander
* Heroes with long lockdowns: 
Shadow Shaman, Legion Commander.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Legion Commander
* Enigma can be a perfect counter-initiator with his ultimate. A perfectly timed Black Hole will turn the tide of any initiation, especially from heroes like; 
Spirit Breaker, Legion Commander, 
Axe, 
Puck, and 
Slardar.
Tinker
* Similarly, heroes with low cooldown teleports can be afraid to split push against X Marks the Spot, such as Tinker and Nature's Prophet.
* In general, highly mobile heroes like 
Earth Spirit or 
Storm Spirit are at a disadvantage against X Marks the Spot.
* Similarly, heroes with low cooldown teleports can be afraid to split push against X Marks the Spot, such as Tinker and Nature's Prophet.
Additional:
* 
X Marks the Spot can be used to prevent Tinker from escape with Blink Dagger or Keen Conveyance, discourage him from snapping farm and snapping gank. However, in later game, it'll be much more difficult because Tinker can buy Black King Bar or Linken's Sphere to prevent Kunkka from placing X on him, or 
Eul's Scepter of Divinity to prevent the recall.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Legion Commander
* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).
Additional:
* Legion Commander relies on her powerful attack and her Duel to be effective. But if Phoenix gets the jump on her first, she can find herself severely slowed, taking heavy damage, and find herself unable to Duel a burning Supernova.
* It must be noted that Press the Attack will both dispel the attack slow of Fire Spirits and grant her or whoever she targets bonus attack speed. This allows her to easily destroy a Supernova if caution is not taken to prevent this from occurring. As such, it would be a better decision to simply avoid a farmed or skilled Legion Commander instead of attempting to overpower her.
* If an ally is caught by Duel, Phoenix can use Sun Ray to heal the ally and damage Legion Commander, possibly swinging the Duel in their team's favor. Or with Aghanim's Scepter, Phoenix can save an ally from dying in Duel with Supernova and cancel the Duel as well.
Legion Commander
* 
Troll Warlord's melee bash and high attack speed can often help him and his allies win Duels against Legion Commander.
Tinker
* Low health spellcasters: 
Lina, 
Witch Doctor, Tinker, 
Keeper of the Light, all rely heavily on their spells and are fragile heroes. They all also have avoidable spells, allowing Puck to get to them and quickly burst them down.
Legion Commander
* Heroes who can hide the Dueled target (Outworld Destroyer, Shadow Demon, Tusk, Phoenix with Aghanim's Scepter etc).
Additional:
* Walrus PUNCH! makes Legion Commander lose Duel easily, especially when she doesn't have 
Blade Mail. Tusk can also snowball dueled allies, preventing them from taking damage for a large portion of the duel's duration.
Legion Commander
* 
Fate's Edict prevents Legion Commander from attacking for a few seconds, potentially saving Oracle's ally.
* 
Fortune's End dispels Press the Attack's healing and attack speed buff, as well as the movement speed bonus from Overwhelming Odds.
* 
False Promise protects allies and prevents Legion Commander from winning Duels and gaining bonus damage.
Additional:
* Provided that the enemy team does not have an Axe, Oracle can guarantee that his ally survives for the duration of the Duel with False Promise and has decent nuke potential to help ally to win a Duel. He can also disarm Legion Commander with Fate's Edict.
* Oracle can dispel enemy buffs like 
Overwhelming Odds and Press the Attack with Fortune's End.
Legion Commander
* Heroes with long disables, like Lion, 
Night Stalker, or Legion Commander, can prevent Oracle from using spells or items.
Legion Commander
* Magnetic Field prevents Legion Commander from getting wins with Duel.
Additional:
* 
Magnetic Field prevents Legion Commander from easily gaining wins with Duel.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: 
Lycan, 
Arc Warden, 
Warlock, 
Chen
Legion Commander
* 
Atrophy Aura's percentage-based damage reduction greatly diminishes Legion Commander's overall damage output, even if she has won many Duels
* Legion Commander cannot get out the way of Firestorm because she is stationary.
Additional:
* Atrophy Aura makes it hard for Legion Commander to win Duels.
* 
Fiend's Gate can be used to save Underlord and his allies from a Duel or to intercept Legion Commander, because outside from Overwhelming Odds, Legion Commander has no other area-of-effect abilities.
Tinker
* Heroes with magical or pure damage output will not have any problems against Atrophy Aura at all: 
Luna, Lina, 
Jakiro, 
Pugna, 
Bane, 
Snapfire, 
Muerta, 
Nyx Assassin, 
Enigma, Tinker, Witch Doctor, Zeus, Crystal Maiden.
Legion Commander
* 
Astral Imprisonment prevents Legion Commander from killing her opponents in Duels.
Additional:
* Outworld Destroyer can save an ally hero caught by Duel with Astral Imprisonment, and he can inflict heavy damage on Legion Commander with Arcane Orb to aid his ally. However, if he gets caught, he is unlikely to survive the duel, due to his lack of durability.
Tinker
* Tinker's Laser is useful against Outworld Destroyer, as the blind prevents him from landing Arcane Orbs.
Legion Commander
* Bane has powerful single-target abilities that can help his allies win Duels, or at least cripple Legion Commander for the duration.
* Nightmare can waste Duel's entire duration as the dueled units transfer the Nightmare back and forth. This may be prevented if a non-Dueling unit attacks the Nightmared Dueler.
Additional:
* 
Enfeeble, 
Nightmare and 
Fiend's Grip all prevent Legion Commander from winning Duels, especially when Bane has Blink Dagger.
Legion Commander
* Heroes with strong dispels can dispel Bane's disables from their allies: 
Oracle, Legion Commander, 
Omniknight.
Tinker
* Tinker is an easy target for Earth Spirit to initiate on. He likes to split push lanes once he acquires Boots of Travel and Earth Spirit can jump him with his Rolling Boulder and disable him to buy enough time for his teammates to come and assist Earth Spirit.
* The huge range of Stone Remnant and Rolling Boulder enables Earth Spirit to stop Tinker from teleporting to his fountain since Tinker tends to buy Blink Dagger most of the time to escape.
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: 
Venomancer, Earth Spirit, 
Ogre Magi
Tinker
* Tinker's Laser has very little effect on Jakiro.
* Tinker has to sit still for a short period of time due to Rearm, not only making it easy to catch him with Ice Path, but also by stunning him while he is Rearming, Jakiro generally spell Tinker's doom.
* With s high area-of-effect and strong damage-over-time capabilties, Jakiro can quickly burn through his 
Defense Matrix, and at the same time lock down his Blink Dagger. Both of which he relies heavily to survive on.
Tinker
* Heroes with good counter-push abilities to clear creep waves can hinder Jakiro's early pushing ability: 
Death Prophet, 
Sniper, Tinker, 
Windranger.
Legion Commander
* 
Static Link drains Legion Commander's accumulated damage, effectively neutralizing her overall primary advantage, and prevents her from winning Duels.
* 
Storm Surge's movement speed buff makes Razor and his allies harder to catch and initiate.
* 
Eye of the Storm, if used beforehand, will always hit Legion Commander during Duels, due to her forced proximity. This drastically lowers her survivability during Duel.
Tinker
* Heroes who rely on abilities to deal damage (e.g. 
Timbersaw, Tinker) can fight a Razor even after Static Link.
Tinker
* Silencer can stop Rearm, preventing Tinker from spamming his abilities/items or escaping.
* Tinker heavily relies on his mana pool and has mana issues throughout the entire game and Silencer's intelligence steal does not help with that.
Additional:
* As Tinker relies heavily on his spells to be effective, 
Last Word and 
Global Silence will render him largely useless.
* 
Arcane Curse effectively prevents Tinker from casting spells during its duration, as he will otherwise suffer heavy damage.
* 
Glaives of Wisdom deal pure damage, which make quick work of fragile heroes like Tinker.
* Silencer's intelligence steal permanently weakens Tinker since he's a hero who requires lots of mana to be effective.
Legion Commander
* Heroes that can disable or silence Silencer for a long time, such as Bane and Legion Commander, can lock down Silencer while their allies put him down.
Tinker
* Tinker is one of the few heroes who is able to defeat a Sniper on the center line thanks to his long-ranged abilities.
* Laser allow Tinker to deal damage to Sniper and blind him, causing him to miss attacks more often.
* Heat-Seeking Missile can deal heavy damage to Sniper on lane.
* Defense Matrix allow Tinker to save himself or allies from 
Assassinate.
* 
Warp Flare from 
Aghanim's Shard allows Tinker to teleport Sniper away from himself, while also reducing both his attack range and cast range. If Sniper is teleported near Tinker's allies with Warp Flare, he will be bursted down in no time.
Additional:
* Tinker is one of the few characters in Dota 2 who is able to defeat a Sniper on the center line – Tinker. On the center line, he gains an advantage over his opponent, and later acquires additional control. It is these abilities that the enemy should have in the game against the Sniper.
Legion Commander
* Sniper's low mobility and lack of defensive abilities make him an easy gank target for the entire game, especially if Blink Dagger is picked up.
Tinker
* Laser along with Heat-Seeking Missile allows Tinker to quickly burst down Drow Ranger due to her low health.
* Heat-Seeking Missile lets Tinker out-range Drow Ranger and hit her in the backline of a teamfight.
Legion Commander
* Drow Ranger's low mobility and lack of defensive abilities make her an easy gank target in the early to mid-game.
* A Dueling Drow Ranger will lose her precious 
Marksmanship, reduce her damage output significantly, and will more likely lose that Duel.
Tinker
* Viper is kind of a mixed package. Tinker is very good against him. but stands a better chance against him than most heroes.
* Viper has a high innate magic resistance, but relies on his primary attacks to really deal damage. making Laser an effective way to save allies from him, and deal damage. Keep in mind that his 
Corrosive Skin will prevent Tinker from blinking.
* Viper's 
Viper Strike and 
Poison Attack will also have a hard time damaging allies through Tinker's constant casting of Defense Matrix.
* Viper has no solutions to cancel Rearm nor any of Tinker's escape attempts with Boots of Travel
* However, if Viper gets a jump on Tinker first. Tinker will unlikely survive versus Viper.
Legion Commander
* Viper's frailty and low mobility make him an enticing Duel target and Corrosive Skin doesn't protect him against Legion Commander physical attacks.
* Press the Attack can dispel Poison Attack.
* Viper slows can easily negate by Overwhelming Odds movement speed.
Tinker
* Heroes with either magical, physical or pure damage burst: Bane, 
Ember Spirit, 
Leshrac, Lina, Luna, Nyx Assassin, 
Phantom Assassin, 
Skywrath Mage, Tinker, 
Ursa, 
Void Spirit.
Legion Commander
* Chen's fragility and low mobility make him an enticing Duel target.
* Overwhelming Odds and Moment of Courage can take advantage of converted creeps's numbers.
* With enough damage from Duel stacks, Legion Commander can also often kill any of Chen's unfortunate allies before he can use Hand of God.
Additional:
* Chen's frailty and low mobility make him an enticing Duel target.
* Overwhelming Odds and Moment of Courage can take advantage of converted creeps' numbers.
* With enough damage from Duel stacks, Legion Commander can also often kill any of Chen's unfortunate allies before he can use 
Hand of God.
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, Techies, Terrorblade, Necrophos, Invoker.
Legion Commander
* Duel is a great initiation to target Crystal Maiden with, as it prevents her from using Freezing Field or any other abilities and allowing the enemy team to quickly kill her before she can aid her team in a fight.
Tinker
* Since Windranger is bad against magical damage, heroes with continuous magical damage or magical nukes can blast her: Zeus, Tinker, Leshrac, 
Viper, Skywrath Mage, Lion, Lina, Venomancer.
Legion Commander
* Press The Attack dispels the stun from Shackleshot.
* Duel can lock down Windranger before she can escape with Windrun.
* Legion Commander tends to go for Blade Mail, which returns the damage she takes from Focus Fire.
Tinker
* Heroes with high armor like 
Dragon Knight, or with abilities to cause attacks to miss like Phantom Assassin, Riki and Tinker will be hard to deal with, as Clinkz relies almost entirely on physical attacks.
Legion Commander
* 
Searing Arrows and Clinkz physical damage items are almost suicidal when used on Legion Commander, as it invites an instant Duel and Legion Commander herself is a natural Blade Mail carrier.
* Duel locks down Clinkz for a long duration, preventing him from escaping with 
Skeleton Walk.
Tinker
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Tinker
* An Aghanim's Scepter upgraded Laser allows Tinker to blind Terrorblade and his illusions.
* Tinker deals incredible amounts of pure and magical damage with Laser and Heat-Seeking Missile combined with Rearm, which will ignore Terrorblade's armor and be devastating to his low health pool.
* Tinker is a hero who very often goes for Blink Dagger, and because Terrorblade has no disable to lock down Tinker, he will be unable to catch up with him nor to prevent him from escaping with Boots of Travel.
* Even if Terrorblade manages to catch up to Tinker, Tinker can simply teleport Terroblade away from him with Warp Flare provided by Aghanim's Shard, which can also weaken Terrorblade's attack range and cast range.
Additional:
* Tinker can single-handedly stop Terrorblade's early-push and quickly clear his illusions with Laser (especially with Aghanim's Scepter).
* Tinker has perfect tools to reveal Terrorblade from his illusions as well as to burst him down if he is low-health before he will be able 
Sunder.
Legion Commander
* Duel's long duration prevents Terrorblade from swapping his health with Sunder.
* Overwhelming Odds deals high damage to Terrorblade's illusions.
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, Techies, Terrorblade, Necrophos, Invoker.
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, 
Lich, Techies, 
Rubick
Tinker
* Heroes who rely on basic attacks will suffer from Laser: Phantom Assassin, 
Wraith King, 
Huskar.
Legion Commander
* Carries that can out damage Huskar will do well against him: Legion Commander, Faceless Void, Troll Warlord, Phantom Assassin.
Additional:
* 
Life Break is almost suicidal when used on Legion Commander, as it invites an instant Duel and Legion Commander herself is a natural Blade Mail carrier.
* Huskar's low survivability and mostly on low health make him particularly vulnerable to Legion Commander's high physical damage.
Tinker
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Tinker
* Laser prevents 
Juxtapose from triggering, as it only triggers on successful attacks
* Laser does high splash, and upgrading it with Aghanim's Scepter makes it deal twice as much damage due to the bounce. Combined with Rearm, Tinker can rapidly deplete Phantom Lancer's illusion army
* However, if Phantom Lancer ambushes Tinker, Tinker will not survive versus Phantom Lancer.
Legion Commander
* Heroes who rely on illusions will see them destroyed easily by Overwhelming Odds: Phantom Lancer, Chaos Knight, Terrorblade, Naga Siren
Additional:
* Overwhelming Odds deals high damage to Phantom Lancer's illusions.
* Duel's long duration prevents Phantom Lancer from using Doppelganger.
Tinker
* All of Tinker's damage is magic/pure and completely ignores Enchantress's 
Untouchable. And Tinker's nukes can quickly decimate her small HP pool, sometimes even preventing Enchantress from even responding.
* As Enchantress relies solely on her primary attacks to deal damage, and rarely builds something to dispel it, Laser's Blind is particularly effective.
* However, Enchantress will probably build a Linken's Sphere against Tinker's Laser, so getting an additional disable is highly recommended.
Legion Commander
* Duel makes Bristleback fight Legion Commander face to face, forcing him to take full damage.
* Press the Attack dispels the slow from stacks of Viscous Nasal Goo.
Additional:
* When dueled, Bristleback will have to face Legion head on, not allowing his passive 
Bristleback to come into effect.
Tinker
* Tinker can break Magnus's Blink Dagger using March of the Machines and Heat-Seeking Missile, therefore delaying any initiation or making Magnus use Skewer or 
Force Staff to initiate. His {Ability ID:Defense Matrix|Tinker} will decrease the duration of Reverse Polarity and can also be cast on all of his teammates with {Ability ID:Rearm|Tinker}. Tinker usually gets his own Blink Dagger as well, which makes him harder to lock down unless Magnus commits Reverse Polarity only for Tinker.
Legion Commander
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Tinker
* Tinker has great map presence because of Keen Conveyance and Rearm, which means he can always teleport and defend towers whenever Nature's Prophet tries to push.
* Laser prevents Nature's Prophet from attacking. Additionally, even with 
Monkey King Bar, Nature's Prophet cannot hit towers and buildings during the effect.
Legion Commander
* Legion Commander's Overwhelming Odds deals damage for every Treant it hits, which allows it to easily wipe out large waves of them.
Tinker
* Illusion heroes, such as Naga Siren, Phantom Lancer, Chaos Knight, Terrorblade will become strong against Tinker in the late game. Without Aghanim's Scepter Tinker is forced to defensively disarm heroes with Laser, leaving illusions free to deal physical damage which Tinker's low armor makes highly effective. In addition, Mjollnir or Battle Fury, two common pickups against illusion heroes, don't work well on Tinker at all.
Tinker
* With Aghanim's Scepter, Tinker's Laser completely stops Chaos Knight's damage, forcing him to buy either a Black King Bar for his own survivability while leaving his illusions still vulnerable, or a Monkey King Bar leaving him still vulnerable to Tinker's nukes, though improving his damage.
* Tinker rarely finds himself in the middle of a fight, which is where Chaos Knight typically thrives, and even in the rare cases of being so, at level 3 Tinker's constant rearm and blink away can kite and dodge Chaos Knight's spells reliably, so Chaos Knight has very little catch against Tinker's mobility. This gives Tinker impunity to create more chaos in a teamfight than Chaos Knight can control, laying down the field with March of the Machines and constantly being hit by rockets and lasers.
Legion Commander
* Heroes with strong area damage to destroy Phantasm illusions: Axe, Ember Spirit, Legion Commander, Phoenix
Tinker
* If Tinker can stay outside of 
Chronosphere, Laser can cause Faceless Void to miss all his attacks.
* Faceless Void has low health and strongly relies on 
Time Walk's healing factor to remain alive. Getting caught by Tinker with Scythe of Vyse will almost always spell a quick end for Void.
* Rearm ignores 
Time Dilation completely.
Tinker
* The blind from Laser prevents Shadow Fiend from attacking for its duration, potentially preventing him from getting a kill.
* Scythe of Vyse can be used to prevent Shadow Fiend from casting Requiem of Souls.
* A combination of Tinker's abilities and his items (like the 
Dagon 5 and 
Ethereal Blade combo) can kill Shadow Fiend quickly.
Additional:
* During the laning stage Laser will reduce Shadow Fiend's last hits, preventing him from getting 
Necromastery souls.
* Shadow Fiend has low health and is vulnerable to Tinker's high magic burst.
Legion Commander
* Duels prevents Queen of Pain from using Blink, which may force her to purchase a Linken's Sphere
* Because Queen of Pain is also not a right-click hero, Legion won't have much difficulties in duels.
* Press the Attack dispels Shadow Strike's debuff.
Legion Commander
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, Tinker
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, Techies, Terrorblade, Necrophos, Invoker.
Legion Commander
* Another great threat to Riki since her Duel forces him to fight from the front and expose him for the entire duration, almost always guaranteeing an easy win (unless Riki has allies helping him).
* Moment of Courage can become hard to deal with as it doesn't cease with silence.
Legion Commander
* Duel pierces spell immunity and forces him to attack Legion Commander, making him unable to use 
Omnislash.
Legion Commander
* Duel's long duration prevents Weaver from activating 
Time Lapse or escaping with 
Shukuchi.
Legion Commander
* Duel is a great initiation to kill Death Prophet before she can cast Exorcism. Furthermore, Legion Commander often builds Blade Mail and can reflect Exorcism's damage to kill Death Prophet easily.
Tinker
* Tinker can use Laser to save an ally or himself from Phantom Assassin's initiate 
Phantom Strike due to the blind, forcing her to use a Black King Bar to effectively initiate, Tinker can also use Warp Flare one he buys Aghanim's Shard to reverse Phantom Strike's blinking with Phantom Strike.
* Tinker almost never uses his physical attack, relying on his spell-spamming to deal damage which ignores 
Blur's Evasion
* Defense Matrix prevents 
Coup de Grace from triggering.
Tinker
* Laser blinds Bloodseeker, preventing him from getting last hits and denies during the laning stage and preventing him from finishing off enemies.
* Tinker always buys Boots of Travel, helping him escape Bloodseeker's early ganks.
* Tinker's heavy magical damage will burst down Bloodseeker during the early to mid game, as he has little health.
Additional:
* Laser can be very effective against 
Bloodrage as the damage will be amplified while the blind prevents Bloodseeker from landing hits.
* Keen Conveyance guarantees him escape from Rupture.
Legion Commander
* Overwhelming Odds's damage stacks with each enemy unit in its radius. If this hits Broodmother and a large number of spiders it can deal significant amounts of damage.
* Moment of Courage has a high chance to proc if Broodmother and all of her spiders are attacking her.
* Duel can keep Broodmother in place long enough for Legion's team to kill her.
Additional:
* Overwhelming Odds is great at killing many stacked up spiderlings, thus giving Legion Commander a large buff.
* Duel is a reliable way to lock down Broodmother, preventing her from running into the treeline.
Tinker
* Laser blinds Lone Druid, making his attacks miss.
Tinker
* Heroes that commonly attack ethereal units will not have any problems against Muerta's Pierce The Veil: Tinker, Jakiro, Lina, Luna, Pugna or Ogre Magi, Enigma, Batrider, Techies, 
Broodmother, 
Dawnbreaker, Shadow Shaman, Bane, Tinker, Venomancer, Arc Warden.
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: Venomancer, Earth Spirit, Ogre Magi
Additional:
* Press the Attack dispels Venomous Gale and Poison Sting from Legion Commander or her teammates.
* Venomancer is an ideal target for Duel due to his lack of mobility and low starting health.
Tinker
* Heroes with powerful spammable abilities will prove problematic for Grimstroke as Ink Swell does not protect him from them: Zeus, Skywrath Mage, Tinker, Lina
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, Techies, Terrorblade, Necrophos, Invoker.
Tinker
* Heroes with Evasion or abilities that cause Tiny to miss like Phantom Assassin and Tinker are very effective because of Tiny's low attack speed. Additionally, Monkey King Bar is not a good item for Tiny because of its reliance on high attack speed to proc for magical damage.
Legion Commander
* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion
Tinker
* Lion has an incredibly fragile health pool, making him weak against nukers like Tinker or Oracle.
Legion Commander
* Lion is extremely dependent on his abilities. Silences like 
Silencer's Last Word, magic resistance like Oracle's Fate's Edict, and dispels like Legion Commander's Press the Attack all make his abilities less effective.
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, Lich, Techies, Rubick
Tinker
* Any hero with a low HP pool is easy for Tinker to nuke down: Crystal Maiden, Enchantress, Gyrocopter, Lion, Riki, Techies, Terrorblade, Necrophos, Invoker.
Legion Commander
* 
Tethered heroes are much harder for Legion Commander to kill in Duels.
* 
Relocate can cancel Duels and save allies.
Tinker
* Heroes with either magical, physical or pure damage burst: Bane, Ember Spirit, Leshrac, Lina, Luna, Nyx Assassin, Phantom Assassin, Skywrath Mage, Tinker, Ursa, Void Spirit.
Legion Commander
* Duel is very effective against Io due to its low health and armor.
Legion Commander
* Special mention to Legion Commander, as she can lock down Void Spirit for a long amount of time without worrying too much about being killed by him during the Duel.
Legion Commander
* Heroes rely on their debuff to control the opponent will have a hard time against Press the Attack: Venomancer, Earth Spirit, Ogre Magi
Legion Commander
* Heroes who rely on summons will see them destroyed easily by Overwhelming Odds: Lycan, Arc Warden, Warlock, Chen
Legion Commander
* Heroes with low health will die easily during Duels, and can be farmed for damage in the early game: Crystal Maiden, Lich, Techies, Rubick
Legion Commander
* Legion Commander with Press the Attack
* Heroes that can remove the Track debuff with their skills:
* 
Abaddon with Aphotic Shield and Borrowed Time
* Huskar with Life Break
* 
Juggernaut with 
Blade Fury
* Legion Commander with Press the Attack
* 
Lifestealer with Rage and 
Infest
* Naga Siren with 
Mirror Image
* Omniknight with 
Heavenly Grace
* Oracle with Fortune's End and False Promise
* Phantom Lancer with 
Doppelganger
* 
Slark with Dark Pact
* Ursa with 
Enrage
* 
Weaver with Time Lapse
* 
Tidehunter with 
Kraken Shell when damage received reaches the threshold.
Legion Commander
* Long lockdown is a great way to deal with Axe to prevent Berserker's Call from being used, heroes such as Legion Commander, 
Beastmaster and 
Primal Beast are good examples of this.
Tinker
* Heroes that can gain vision over trees to catch Tinker: Invoker, Shadow Demon, Batrider.
Legion Commander
* Press the Attack dispels Flaming Lasso.
* Batrider is unlikely to win a Duel in any stage of the game.
Tinker
* Anti-Mage's high mobility from Blink and tendency to build Battle Fury makes him strong against split-pushing heroes: Nature's Prophet, Tinker, and Arc Warden.
Additional:
* Tinker is fragile and vulnerable against carries like Anti-Mage.
* 
Mana Break burns away his mana pool and deals bonus physical damage.
* Tinker's massive mana pool makes 
Mana Void deal large amount of damage, and can be used to cancel a Keen Conveyance teleport.
* 
Blink gives Anti-Mage many options, like disjointing Heat Seeking Missiles. He can use Blink to wait out of sight for a split pushing Tinker or chase a blinking Tinker into trees.
* Tinker doesn't want any of his spells reflected back at him through 
Counterspell.
Legion Commander
* Duel renders Anti-Mage's escape capabilities with Blink and Counterspell useless. Blade Mail and Moment of Courage work well against Anti-Mage's relatively low health.
* A good initiation from Legion Commander and her team is enough to effortlessly kill Anti-Mage.
Additional:
* Counterspell offer no protection against Duel at all.
* Duel locks down Anti-Mage for a long duration, preventing him from escaping with Blink. One successful Duel initiation is usually enough for Legion Commander's team to kill Anti-Mage.
Legion Commander
* Heroes with abilities that blind or cause Legion Commander to miss will prevent her from winning Duels: Arc Warden, Keeper of the Light, Riki, Tinker
Legion Commander
* Press the Attack can dispel Blinding Light or Solar Bind from a hero.
* Duel can be used to instantly take Keeper of the Light out of a team-fight.
Tinker
* Timbersaw's ability to destroy trees can be a serious problem for some heroes that use them, as either a way of enhancing their spells like Treant Protector, or heroes that tend to hide inside of them like Tinker and 
Monkey King.
Tinker
* All Tinker's damage is magic/pure and completely ignores Timbersaw's 
Reactive Armor.
* Timbersaw very rarely builds Black King Bar, making him very vulnerable if Tinker builds Scythe of Vyse.
Legion Commander
* Because Duel requires both combatants to face each other, 
Bulwark's effectiveness will be increased by a huge margin, which makes it much more difficult for Legion Commander to win any duels against him.
* 
Spear of Mars and 
God's Rebuke pushes Legion Commander away during Duels against allies.
Additional:
* Bulwark immensely mitigates Duel, even with bonus physical damage, as Bulwark scales by percentage. Mars can also buy time for a dueled ally by pushing Legion Commander away with Spear of Mars.
Tinker
* Heroes with high magical or pure damage will bypass Bulwark: Timbersaw, 
Dark Willow, Enigma, Invoker, Pugna, Skywrath Mage, Tinker, Zeus, Oracle.
Legion Commander
* Legion Commander is both good and bad vs Mars, on the plus side she can dispel Spear of Mars with Press the Attack and is a good 
Silver Edge carrier. However, Mars is not an ideal Duel target, as Bulwark will force her to 1: Buy Silver Edge, and 2: Hit Mars with it before the Duel, allowing a skilled Mars to react, especially with Eul's Scepter of Divinity. In teamfights, Mars will happily draw attention after using his abilities, and tank the Duel with all spells on cooldown.
Legion Commander
* Heroes that lack burst damage will have a difficult time taking down Monkey King, and fare badly against Jingu Mastery: Legion Commander, Lifestealer, Weaver, Wraith King
Tinker
* Heroes with wide AoE abilities will reveal Monkey King through Mischief: Necrophos, Phoenix, 
Alchemist, 
Earthshaker, 
Razor, Tinker, Leshrac, 
Queen of Pain
Legion Commander
* Heroes that cannot move in fights such as a Dueling Legion Commander or anyone channeling a spell like Bane, 
Pudge, or Enigma are easy Sacred Arrow targets.
Legion Commander
* Heroes that can protect or dispel stunned allies such as Legion Commander, Outworld Destroyer, Shadow Demon and Oracle can reduce the effectiveness of Sacred Arrow.
Tinker
* Heroes with unorthodox escapes will struggle against Primal Beast, such as Nature's Prophet, Tinker, and 
Templar Assassin.
Tinker
* Heroes who can do scaling health damage to Primal Beast are very threatening for the hero. Such as: Phoenix, Tinker etc.
Tinker
* Meat Hook can be used to pull Tinker to Pudge while he is hiding in the trees, and a follow up with Dismember and Rot can lead to a valuable kill, as Tinker doesn't buy many survivability items.
* Flesh Heap makes it hard for Tinker to deal serious damage.
Additional:
* Pudge can 
Meat Hook a Tinker hiding in the trees and follow it up with 
Dismember and 
Rot for an easy solo kill, as Tinker doesn't tend to buy survivability items.
* Many stacks of 
Flesh Heap combined with items that give Pudge high strength and health will make it hard for Tinker to deal serious damage to Pudge.
Legion Commander
* Legion Commander can use Press the Attack on an ally to dispel Dismember. The bonus health regeneration also partially counters the damage of Rot
* Duel can be used on Pudge whilst Rot is active, disabling toggling which may result in a lethal health drain that leaves Legion Commander with a successful duel.
Tinker
* Heat-Seeking Missile allow easy Spiked Carapace stuns.
* As a fragile hero that relies on mana and intelligence items, Tinker is vulnerable to Mana Burn.
* Nyx Assassin's stuns can interrupt Rearm and leave Tinker helpless.
Additional:
* Nyx Assassin's whole skillset is good against Tinker:
* 
Impale prevents Tinker from blinding Nyx Assassin or fighting back, while giving Nyx' allies time to catch up to Tinker's position.
* 
Mind Flare generally deals more damage to intelligence based heroes like Tinker.
* 
Spiked Carapace can stun Tinker at a moment of Nyx Assassin's choosing if March of the Machines has been cast. It is also quite easy to time Spiked Carapace against Heat Seeking Missiles.
* 
Vendetta allows Nyx to approach Tinker in the trees or wait for him in common hiding spots and deal heavy damage to his low armor.
Legion Commander
* Duel's long duration prevents Nyx Assassin escaping from Vendetta. With Aghanim's Scepter, she can also bypass Spiked Carapace.
Legion Commander
* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion
Legion Commander
* Pudge, Legion Commander and Axe will make the match a living hell for Shadow Shaman, since they are known for surprise attacks from the fog and quickly killing low HP heroes. They can also interrupt Shadow Shaman's channeling, Legion being especially problematic, as she can use Press the Attack on an ally who is hexed as well.
Legion Commander
* Wraith King's 
Reincarnation allows him to severely punish Legion Commander after he revives, as her abilities are on cooldown. Legion Commander is still awarded a Duel win if Wraith King reincarnates.
Additional:
* Wraith King makes a poor Duel target, as he can be already quite hard to bring down once, and then you have to worry about his second life.
* However, even if Legion Commander does win the duel when Reincarnation is off cooldown, she still receives the permanent victory damage bonus because taking down Wraith King's first life still counts as a "kill".
Tinker
* Heroes who rely on basic attacks will suffer from Laser: Phantom Assassin, Wraith King, Huskar.
Legion Commander
* 
Cold Embrace saves allies from dying in Duels.
* 
Winter's Curse turns Legion Commander's high damage against her allies, giving the enemy team little time to react.
* However, Winter Wyvern lanes very poorly against Legion Commander due to Press the Attack removing all the debuffs she can give. Winter Wyvern also has little chances of surviving if she gets Dueled herself.
Additional:
* Cold Embrace is very effective against Duel.
* Also, casting Winter's Curse at Legion Commander while an ally is in a Duel will stun her for most of the duration, possibly preventing lethal damage dealt to your ally. It can also turn her high-damage against her teammate.
Tinker
* All of Tinker's damage is magical and pure, which makes Cold Embrace a good setup for his nukes.
* Winter's Curse is very hard to cast on Tinker because he usually stays in the back-lines in team-fights. In turn, Tinker has mediocre attack damage and will contribute very little when he is cursed to attack an ally. He can also save his ally under Winter's Curse effect with Ethereal Blade and Defense Matrix.
Legion Commander
* 
Fury Swipes can give Ursa the edge in Duels.
* Enrage's instant cast time allows it to be used before Legion Commander initiates a Duel, causing Ursa to take almost no damage for a brief period of time.
* However, Duel stops Ursa from casting Enrage at the most critical moment
Tinker
* Laser can be cast on a initiating Ursa, normally causing him to waste multiple 
Overpower attacks, forcing him to either Black King's Bar, or Enrage to protect himself.
* Ursa will probably carry a Linken's Sphere to counter Tinker's Laser. Popping it with Scythe of Vyse is actually preferable, due to Laser's high Pure damage.
* While Ursa is a common Blink Dagger carrier, but he otherwise has no way to close the gap, Baiting him into using his Blink, then blinking away, allows Tinker to easily kite Ursa.
* Enrage is generally how Ursa disengages, Due to Tinker's high maneuverability, he can follow him until it runs out. then burst him down with high magic damage.
Tinker
* Rocket Flare can find Tinker if he blinks into the treeline, and Hookshot will prevent him from teleporting out.
Rearm by stunning him repeatedly.
Hookshot and prevent him from escaping with 
Power Cogs and 
Battery Assault. Clockwerk can also find a Tinker hiding in trees with his 
Rocket Flare.
Blade Mail, which does lots of damage to Tinker if he gets hit by his abilities (especially March of the Machines).
* Battery Assault makes Tinker unable to
Additional:
* Clockwerk can easily catch a split pushing Tinker with his
* Clockwerk usually buys a
Legion Commander
* Battery Assault's mini-stuns can severely disrupt Legion Commander's attack animation when she enters a
Duel, potentially saving Clockwerk (or his allies) and possibly even giving him an edge in securing a win himself.
Duel.
* Power Cogs pushes Legion Commander away from Clockwerk's allies when she enters a