Tips

• Your Barracuda innate can be very useful for counterwarding. If you're walking around and you lose the Barracuda buff, you'll know you've wandered into enemy vision.
  • So carry your own sentry wards. I'm serious. Yes, I know you're a carry, you've probably never clicked on the item in your life, but do it. Did you know observer wards give gold when you kill them? It's a net profit, I promise.
• Dark Pact is a 'nuke' like Lifestealer's Infest can be a 'nuke.' Yes, the spell can deal healthy damage, but that's not its only purpose. Don't yank the Pact ripcord the second you get in melee range of your gank target. Wait for them to turn around, or for their teammate to come in to save them, then pull the trigger and wipe off any potential disable. If you need to use Dark Pact for damage, only use it if you're sure the enemy can't stop you or try to save it for the killing blow.
• Dark Pact can't remove a lot of things despite being a strong dispel. A few ones worth remembering are Ancient Apparition's Ice Blast, Bloodseeker's Rupture, Invoker's Deafening Blast, Witch Doctor's Maledict, Razor's Static Link, Ursa's Fury Swipes, or Viper's Viper Strike. If you want to get rid of these spells, too bad.
• Each tick of Dark Pact strong dispels Slark.
• Pounce won't latch illusions, making it useful for identifying the real Chaos Knight/Phantom Lancer/Naga Siren.
• Pounce can hit and leash invisible units, but it won't give any vision of them.
• Pounce connects with debuff immune/BKB'd targets, but the leash won't restrict their movement.
  • If you take the "Leeching Leash" facet you will get Essence Shift stacks when connecting on debuff immune enemies.
• Leashing enemies with Pounce will cancel their TPs and prevent them from TPing or using most movement spells while leashed. Mechanically, leashes function very similarly to roots.
• Take advantage of your free pathing state in Pounce when you're escaping. Don't just leap along down the lane, jump over a tree line or clear a cliff to create a gap.
• Orienting Pounces to go where you want them to can sometimes be challenging when the game's pathing doesn't cooperate. A handy console command to work around this is:
  
        cl_dota_alt_unit_movetodirection true
  
  This command makes it so that whenever you're holding down ALT, your hero ignores pathing and tries to move in a straight line towards where you right clicked. You can also enable the "Directional Move" hotkey in the settings, but this ALT modifier may be easier to use once you get used to it.
  • This console command can also be helpful for aiming spells when escaping over cliffs like Mirana's Leap, Pangolier's Shield Crash, Ursa's Earthshock, or Zeus's Heavenly Jump.
• Capitalize on Essence Shift stacks. Take a tower or TP to another lane and use all the damage you have to continue snowballing. Don't just sit around and farm, the enemy should be scared of how much damage you have after winning a fight.
• You will lose all Essence Shift stacks on death, including deaths from Aegis. The enemies will still be missing their stats for the full duration, however.
• You need to be within 300 range of a target dying with the Essence Shift debuff to get the permanent AGI. Or if you get the kill credit, the enemy can be at any range.
• Enemies can still see the TP particle effect when you start channeling under Shadow Dance.
• Slark is one of few heroes that has 1800 night vision.
• You can't cast Shadow Dance while channeling a TP unlike other invis spells, but you can use Shadow Blade or Shadow Amulet mid-channel.

Counters

• Dark Pact dispels as often as it damages, meaning that there are 10 little mini-strong-dispels throughout the duration of the spell. So don't bother trying to stun Slark mid-Pact, just wait for the spell to end.
• If Slark Pounces on you, don't just immediately mash your stuns on him. Bad Slarks usually pop Dark Pact the moment they jump on someone because most enemies panic and use their disables as soon as this fishy boy starts stabbing them. Instead, accept the fact that you got caught, gamble that a Dark Pact is about to come out, then use your stun after you see Pact used. You may still die, but you might force him to use Shadow Dance to stay safe.
  • If you're playing against a smart Slark, you can go one layer deeper and cast and cancel your stun spell animation to bait out the Dark Pact.
  • Keep an eye on his mana bar to verify if he actually cast Dark Pact or not.
• Ground targeted spells (especially ground targeted stuns like Lina's Light Strike Array, Leshrac's Split Earth, Nyx's Impale, etc) are highly valuable against Slark for hassling him whenever he activates Shadow Dance.
• Inexperienced Slarks have a tendency of going for long-range Pounces which are fairly easy to juke. Line yourself up with him when you're getting chased to tease the Pounce out, then move straight left or right and dodge it.
• If you manage to move your hero outside the edge of the Pounce leash, it'll break. That means weird things that provide collision, like planting an Iron Branch or getting shoved by an Earthshaker Fissure or Tusk Ice Shards will break the leash. So do other repositioning spells, like getting kicked by an Earth Spirit Boulder Smash, getting Meat Hooked by Pudge, or even a lucky Manta Style rearrangement.
  • If you go for the Manta Style method, your best bet is to activate Phase Boots before Mirror Image to reduce your chances of collision with an illusion pushing you back into the leash.
  • If you go for the Branch planting method, either portrait casting or casting the Branch inside your hero's selection circle between your hero model and the leash is surprisingly reliable at breaking out of a Pounce. This Branch trick also works against Disruptor's Kinetic Field.
• You can't Force Staff out of Slark's Pounce leash, but you can break the leash by Hurricane Piking any target that isn't yourself.
  • Piking any target that isn't yourself works. You can even Pike an ally, which is theoretically just like using a Force Staff on them, and it'll free you from Pounce leash.
  • However, if an ally is Pounce leashed, you can't use Pike on them to save them.
  • You can Harpoon out of Slark's Pounce. I say 'out of,' but really, you just need to cast Harpoon on anything, including Slark himself, and it'll instantly end the leash. You don't need to 'break' the leash with distance to end it.
• Debuff immunity/BKB allows you to walk out of Slark's Pounce leash.
• If Slark is trying to escape, attempt to intercept his Pounce out by standing in front of him so he'll hit your hero instead of making a getaway over a cliff.
• Slark cannot Pounce when rooted or leashed.
• Essence Shift is the long con. You may think you're winning these exchanges in lane because Slark has awful HP, but he's gaining a Slipper of Agility and you're losing an Iron Branch's worth of stats every time you trade hits.
• You'll get your Essence Shifted stats back when you respawn, but Slark will still have them as well. This is true for Aegis respawns as well.
• Slark's Essence Shift passive and HP regen from his Barracuda innate can both be disabled by Breaks.
  • Breaks can be provided with items like Silver Edge or Khanda. Spells that Break include Hoodwink's Sharpshooter, Phantom Assassin's Agh's Shard Fan of Knives, Shadow Demon's Agh's Scepter Demonic Purge, Viper's Viper Strike, and a few others.
  • Silver Edge's Break is especially strong against Slark since it cannot be dispelled.
• Ghost Scepter can help supports survive Slark ganks.
• Ancient Apparition's Ice Blast can prevent Slark from healing even during his active Shadow Dance and can't be dispelled.
• Bloodseeker notably counters the dickens out of Slark. Slark doesn't like to be silenced, he can't Dark Pact off Rupture, and if he loses too much HP he'll make BS Thirsty and give him global true sight, thus preventing his Barracuda innate regen.
• Spirit Breaker is irritating for Slark to deal with since Dark Pact can't dispel Charge and since Charge will provide vision the whole time, Slark can't regen from his Barracuda innate unless he activates Shadow Dance.
• Slark can't dispel Disruptor's Glimpse, making Glimpse into Static Storm+Kinetic Field often lethal.
• Naga Siren's Song turns off Slark's Shadow Dance active and reveals him, thus stopping Slark from regening and being invisible. The Dance will continue once the Song ends, though.
• Gleipnir can root Slark even when he's untargetable in Shadow Dance.