While not being a particularly versatile hero, Viper is one of the best in the game at what he does. His in-build survivability, lane dominance, control AND damage in fights and relative item independence make him an invaluable addition to aggressive 5-man Dota lineups.

Viper’s ability to win his lane consistently and then use this advantage to win fights and snowball make him an extremely hard hero to counter. He is not flashy, but he is extremely consistent and playing him well can easily win you fast games and propel you in the rankings.

There are three main reasons why you want to pick Viper in a strat:

First and foremost, Viper is a very strong laner and can sometimes completely shut down the enemy hero against him. You can pick Viper to dominate the lane and then use the gained advantage to snowball and secure the win as early as possible.

Second, combining Viper with other aggressive 5-man pushers and fighters could make it almost impossible for the enemy team to handle your aggression in the early-mid game. This often results in a 20-30 minute win. Moreover, since he scales well into the late game, a 5-man push strat with Viper is not an all-in strat and even if you don’t win the game early you always have a chance to secure the victory in the late game (unlike e.g. a Huskar strat).

Third, Viper is a good pick to counter an immobile enemy carry that relies on spell immunity to stick to his/her targets (Ursa, LS, TA, Sven) and to heroes weak against the break mechanic (Spectre, DK, PA, Bristle, Huskar).

Viper in is usually picked for his laning strength, i.e. you want to dominate the lane or at least do well in the lane even against a traditionally strong opponent (e.g. QOP). Thanks to his Poison Attack, Viper can harass and zone out most heroes in a 1v1 situation and on top of that it's very hard to fight him back because of Corrosive Skin.

Equally importantly, a solo lane allows Viper to get a lot of experience and farm, which helps him start playing more aggressively after the laning stage in order to force fights with his team an claim map control.

Viper needs a lot of experience and will usually do better in a solo lane. Nonetheless, a dual lane with Viper could also work great in some situations. If you combine him with a hero that can sustain Viper’s HP (IO, Abaddon, Dazzle, Treant) or more aggressive supports (Tusk, SK, Naga) Viper can potentially zone out and harass even two heroes and possibly has kill potential early on. You can build strong offensive dual lanes that shut down the development of the enemy cores while also keeping the enemy supports busy. 

Good friends to have are:

Strong Against:

Weak Against:

The skill builds of Viper follow the logic of his play style – the goal is to maximize your laning strength in order to win your lane and snowball in the early-mid game fights. You prioritize Poison Attack to do this because it is your strongest harassing skill. Corrosive Skin comes next, as you want to be tankier in fights and hard to harass in lanes.

That being said, investing more points in Nether Toxin for a more passive farming game is certainly possible, but it is not the usual play style for which you pick the hero.

A lot of different items can work well on Viper. The decision you have to make usually is if you want to increase your farming speed or if you want to make yourself tankier in order to take fights right away. You also need to decide whether you'll boost your magic damage potential or get traditional carry items to become a physical damage dealer.

This is a team-fight, early push oriented build for Viper. You want to get your cheap stat items as early as possible and then group up with your allies to force fights and take towers. The benefit is that you are very tanky and you can play on the frontlines. The drawback is that you don't farm as fast and need to apply pressure constantly rather than play passively.

(If needed, it is possible to invest in team-centric items in the early-mid game like e.g. Pipe.)

Heart and Butterfly make Viper even tankier in the late game. Of course, Butterfly also gives him very good DPS potential. If you need more damage, get Butterfly before Tarrasque. If you need more EHP – get Heart first. If the game goes late you can get Mjollnir to increase your DPS further (it synergizes very well with your lvl25 damage talent) and make it easier to push-out waves.

The build focuses on giving you cost efficient stats while also increasing your farming potential with the AoE proc of Maelstrom and later on Mjollnir. 

Since you want to right-click freely with this build, a faster BKB is usually necessary to avoid getting controlled in fights. Your late game choices are open, but usually, you want to emphasize on additional AS (because of your DMG talent). Bloodthorn + Nullifier is the cookie-cutter DPS late game combo if you want to be able to dish out very high damage. Alternatively, if you feel you need more survivability you can go for stat or armor items like Skadi, AC, Shiva, etc.

The build maximizes your magic damage output in fights in combination with some tankiness.

Atos incerases your kill potential in the early-mid game while also providing early-game stats. Greaves helps you utilize your mid-game power spike to walk together with your team, posh towers and force fights.

What you buy from that point is situational. Usually you want Aghanim's to buff your ultimate. Kaya & Yasha is well rounded and further buffs your magic damage output. In the late game in this example we go for Octarine and Shivas to make you extremely hard to kill and further buff your magic damage output. It is a viable option, however, to transition into right-click items for the late game if your team lacks physical damage dealers.

Although Viper isn’t a farm-dependent hero (for a semi-carry), you usually want to get some items early on (PTs, Drums, Wand, Dominator, Dragon Lance, etc.) that allow you to fight in the early-mid game.

When it comes to last-hitting, your primary tool will be your zoning abilities. First zone-out your opponent then last hit the creeps (of course if it’s possible).

The main reason why Viper is a strong laner is that he has a lot of zoning out potential thanks to his skill set, mainly his 1^st ability.  Poison Attack is one of the best skills in the game for harassing: it has a high range, orb-walking capabilities, damage and slow. The best way to zone out and harass is using the so-called “Orb Walking” technique. By manually casting Poison Attack on the enemy you don’t aggro nearby enemy creeps. As a result, you can preserve a favorable creep equilibrium (which helps both in last hitting and harassing) and harass the enemy at the same time.

If the enemy decides to fight back, he/she will get slowed and damaged by Corrosive Skin even more. The more damage he/she takes, the more damage your Poison Attacks will deal. If your opponent runs out of regen you will be able to totally zone him out by staying between him and the creep wave and in this way dominate the lane (good creep equilibrium is vital for this).

Viper is a slow hero and doesn’t have any escape mechanism, which means that if you are getting ganked you can hardly disengage. Nonetheless, you are quite tanky, so if your supports can teleport quickly you can potentially turn a gank around. If you know that enemies have potent gankers early on, don’t over-extend by standing between your opponent and the creep wave.

If enemy heroes are initiating on you, your best bet is to use Poison Attack (and ultimate if you have one) at a target that needs to get close to disable or deal damage to you and then start running away. Sometimes the three MS slows you have will be enough to help you disengage.

Viper deals a lot of damage even without items thanks to his skill set. A downside, however, is that he doesn’t have any lock down apart from slows. An enemy can as a result teleport away or use an escape mechanism to disengage.

In the laning stage, you constantly harass the enemy and he/she is often at low HP. Since you deal more damage the lower the health of your target, you can quickly burst a hero down if he makes a mistake and overextends.

Your kill potential increases greatly when you get your ult - you typically want to initiate on a target with your Viper Strike to apply the DoT damage and slow. The faster you lower the HP of the target, the more damage you will deal. Therefore, even though Poison Attack might be sufficient to slow down the MS of the enemy, using your ult right away to get a kill is essential.

After using your ultimate you auto attack using Poison Attack to finish the kill. If you have Nether Toxin throw it right after the ult to apply the damage AMP while the target is slowed.

It is a good idea to check if the enemy has a TP scroll in the inventory before initiating on your own. If he does, he might simply teleport away. However, even in such a case attempting a kill is worth it since you force him to teleport to his base. The best case scenario to get a successful kill on such a hero is to have an ally with a disable (that can cancel TP’s) to help you out.

Viper does not excel at rotating around the map. As we’ve already mentioned he is a slow, immobile hero with predictable movement. You usually want to pressure the enemy tower in your lane and when you get some items you want to rotate to a lane to push together with allies.

The only time you should rotate from your lane early is to join a fight. Since you deal a good amount of damage even without items and on top of that have good control, you are a hero that can easily punish the overextension of enemies. You can, for example, teleport on a tower when enemies are diving and to get a kill or two. 

In a 1v1 you should try to zone out and harass as much as possible to stop the development of your lane opponent. This will also create space for you to free farm. Only if you can’t zone out effectively you should focus on winning the last hit war, but even in such a case don’t neglect to harass as it could possibly set up a kill when your supports rotate.

Starting with Wraight Band in mid is standard, later upgrades it to Aquila. In the lane, Viper is using almost every chance to put Poison Attack on Razor. Viper is not in the best matchup for him (Razor, which is one of the best heroes against Viper ), but with the help of Bounty Hunter, they manage to kill Razor early. At minute 4 Bounty belted Razor to the rune and they manage to kill him again, which is quite good for Viper because if there are no kills in this lane, Razor should dominate it quite easily. Getting Rain Drop with Magic Wand is always good against Razor. Also getting Phace Boots in this game instead of Power Treads is better (you can escape Razor`s Link easier).

In a dual lane, Viper has a similar role to that in a 1v1 situation. In a 2v2 or 2v3, you benefit even more from the fact that you are quite tanky and enemies can’t harass/zone you out easily. If you have a good support to back you up, enemies won’t be able to force you away, while you can zone them out and get a lot of last hits.

Your primary job is to abuse your lane dominance and force your opponents away. Of course, you are a carry, which means you shouldn’t neglect your farm.

In the lane, you want to exploit your early game harassing and kill potential.

You shouldn’t worry too much about getting zoned out or killed – you are very tanky and have a high range which should make it quite hard for enemies to force you out of farm range. Your skillset allows you to win most man-fights in the early game so if your opponents are trying to fight you back, you should stand your ground (you can use heals to help yourself win the exchange – tango, faery fire, wand).

The best dual lane partner of Viper is a hero that boost up Viper’s survivability to a point where you can’t kill or even zone out the hero no matter what you do. Healers or heroes that shield up Viper make him extremely tanky – if enemies can’t kill him and play passively, Viper can in turn zone them out and force them out of the lane. (Bane in the examples doesn’t fit this category, but he is also a great partner because he can help in harassing and dominating the lane.)
Examples: Abaddon, Treant Protector, Dazzle, Bane

Heroes with good kill potential (control AND damage) could also work very well with Viper as a partner in the lane, especially against opponents without escape mechanism.  Such lane combinations are most effective in the side lanes because there you have more space to chase targets down with Poison Attack and secure the kill. In the mid lane, such heroes can simply gank your lane while spending most of their time elsewhere.

Examples: Tusk, Naga Siren, Skywrath Mage, NS, Bara

The best timing for Viper is the mid game. After having won the laning stage it is time to build cost-efficient stat items and to pressure your enemies as a team. They will likely not be able to win 5v5 fights at this stage, which will allow you to get some kills and claim map control.

If you reach the very late game your timings are similar to all other AGI carries – it is smart to fight just as you finish items that amplify your carry potential, such as Butterfly.

If the laning stage goes well and you have your core items, you should use the advantage to pressure enemies by forcing engagements and pushing.

It is quite important to have a good early game stage because it is hard to force favorable fights if you are at a resource disadvantage. This is a problem because you cannot afford to play passively and simply farm up – more often than not the enemy team will have harder carries that farm faster. If the laning stage does go poorly, you should still be able to contribute a decent amount in fights - you don’t need many items to be effective. Try to use your early-mid game strength to force and win engagements to offset your laning disadvantage, but chose your fights wisely (e.g. don’t stand alone at the front lines hitting towers because if you are not tanky enough through levels and items the enemy team will quickly initiate on you and kill you). Getting at least Maelstrom to increase your GPM is also a good idea because if you are behind your goal will be to reach the late game anyway and you will need the extra farm. Hurricane Pike is also an important item because it will help you reposition yourself in fights if dangerous enemy carries jump on you.

In team fights, you are usually the front line hero that tanks up damage and attacks as many targets as possible.

Things to consider before you engage:

Before you go into the fight, you should consider your survivability and the items you have so far. If you had a good start and have a lot of items/levels compared to your opponents, you should go in front, use your ultimate and try to tank up for your team. If you had a bad start and you are under-leveled and have little farm, you should stay behind instead of entering the fight first.  You will be more useful for your team if you deal damage since you can deal quite a lot even without items thanks to your DoTs.

Without some tanky items, you can get burst down even though you are naturally tanky. Therefore it is best to wait for someone else to initiate and then join in the fight by using your ult on the most important target to slow down (usually the enemy carry).

How to move & survive in a fight:

You are a ranged hero and you have no reason to go into melee range. Try to kite low range/melee heroes by using your Poison Attacks and your Viper Strike. The main decision you have to make is where you move each time you attack a hero. You have two options – either make a step backward to move away from danger or go forward to chase down a hero. If you face a low ranged or melee hero that does a lot of damage if he gets close, it will be better to go back so that you can kite him rather than stay and man-fight him in one place. If you focus a squishier hero that can’t fight back, it will be better to go in after him to be able to finish him off.

Viper is a position-dependent hero because he is slow and it is hard for him to reposition in fights. Therefore you should stick to your allies. If you are too far from them, you will arrive too late if a fight breaks out. Alternatively, you can get initiated upon while you are isolated and get burst down since you don’t have an escape mechanism.

The same rule applies to a fight. If you chase down for too long after a target you wouldn’t be able to rejoin your allies quickly – it is better to stick relatively close to your allies because your function as a tank and your control are important for their survival.

Who you should focus on:

Usually, you want to focus the enemy carry with your spells. Use your Viper Strike on the carry right away as the fight starts, especially if you have Aghanim and the CD is low. After you use your ultimate, immediately use your second spell too (-25% magic resistance means more damage).

Try to poison as many heroes as you can with your Poison Attacks and ultimate. You can, in theory, keep 2-3 targets slowed by using Poison Attacks (realistically it is hard to slow more than two heroes because the debuff duration is only a few seconds). This strategy, however, makes sense only if you face enemies that have little mobility and will be crippled by your disables. Otherwise, it is best to focus one target to kill it off as fast as possible. If a hero gets low on HP, you should switch to this target to bring him down quicker – remember that your Poison Attack increases your damage quite a lot in such situations. Therefore, it can be said that the low/lower HP targets will be your priority in general.

Always use your Nethertoxin, even if you are not able to hit or use your ultimate. Nethertoxin reduces magic resistance, which can help your teammates bring a target down faster. Ideally, you want to use it against heroes who have powerful passives, but if this is not the case you can throw it on whoever your team is focusing.

Example:

Matumbaman buys back into the game to defend his base and shows how hard Viper could be to kill. He activates BKB and he constantly moves as he is attacking, making it more difficult for his opponents to focus him down. As a result, he stays alive and successfully defends his base.

Pushing:

Viper isn’t the fastest pusher but he fits pushing strategies quite well. He is tanky and attacks from a distance – if you stay at maximum attack range and hit the tower, enemies will have to commit a lot to kill you.

Just standing in front of your teammates creates a problem for your opponents. If they initiate on you they will get affected by Corrosive Skin, which makes you an unprofitable target to focus first in a fight (especially if you are tanky because of items). Going past you, however, is also very difficult because of the slow of your ultimate and attacks.

Generally, you want to stay at maximum range and hit the tower. You shouldn’t dive in and overextend since you are a slow hero and you can’t get back fast. As a result, enemies will be able to initiate on you and kill you before your allies can help you out.

If you have Aghanim you can even spam your ultimate to whittle down the HP of the enemy heroes. You can run in, cast your ultimate and get back. You shouldn’t overcommit to do it though, you have a high cast range (900) and you should be able to use it from afar.

If you have a squishier DPS item build and another frontline hero you can choose to stay at a safer distance and join the fight once the enemy team initiates.

Split-Pushing:

Split-pushing is not a good idea with Viper because of your low mobility, slow wave-clear, and not-that-good tower damage.

Instead of split-pushing you should just use Nethertoxin to push out the waves and go back closer to your teammates. 

Generally, ganking with Viper isn’t your job – you are slow and your movement is predictable. Moreover, enemies can simply teleport away since your disables are only slows. Therefore if you want to gank you should do it together with an ally that has a disable and the point of the gank shouldn’t be the pick-off itself but to force a fight and to push objectives afterward.

If you have Shadow Blade you could be the initiator by going close to your target and starting the fight with Viper Strike. You would usually still need another hero with a reliable disable with you to cancel TP’s or control heroes with escape mechanisms.

It is typically better, however, to force fights and push together with your team rather than gank lone targets. In even games, it is usually worth it to attempt a smoke gank on an enemy core hero and then push in order to provide your team with a numbers advantage in the push and make it more difficult for your opponents to defend.

As we mentioned already, Viper is not a fast farmer. Therefore farming passively shouldn’t be your play style. Nevertheless, you should farm during any available off-time – when you are waiting for an ally to get an important item or after a successful engagement etc. You can also focus on farming if you are close to a key item like Pike or BKB that can significantly boost your team fight presence.

The mechanics of farming with Viper are quite simple – you put your Nethertoxin on the ground and last hit the creeps. Let the creeps hit you at least once to apply Corrosive Skin on them. Spread out your Poison Attacks on as many creeps as possible, especially when they are on low HP. Of course, you need to have good mana sustain to do this all the time (you can carry clarities with you).

If you need to significantly increase your farming speed get a Mjollnir.