Poison Attack:

Slows speed by 10%/20%/30%/40%, deals 10/16/22/28 (v6.74 Changelog) damage per second.

My opinion: Poison Attack is the ultimate chasing/harassing skill. At level 4 of Poison Attack, the 40% speed reduction means that the opponent has no way of outrunning the Viper. It's either run and die, or turn back and die. (Assuming he has no TP scroll.) The damage per second is also a good way to harass opponents in the lane. Not much mana is consumed to use Poison Attack, so it is spammable and very painful. Definitely Viper's signature skill. Great for scoring kills.

Nethertoxin:

Maximum of 32/64/96/128 bonus damage.

My opinion: Nethertoxin simply helps to settle enemies fast. The lower the existing HP of the enemy, the more the bonus damage. Nethertoxin will not be much of a problem in the first few attacks, but will slowly start to increase in damage as the opponent's HP falls.

Corrosive Skin:

10%/15%/20%/25% slow, 10/15/20/25 damage per second and 10%/15%/20%/25% magic reduction.

My opinion: Viper's survivability skill. On top of the damage per second from Poison Attack, enemies who attack Viper take further damage and greater slow. The magic reduction comes in helpful against high damage nukes.

Viper Strike:

Deals 60/100/145 damage per second for 5.1 seconds and slows speed by 40%/60%/80%.

My opinion: That's a really good ultimate. The damage per second will make most enemies turn back and try to run; however, the slow from Viper Strike prevents him from doing so. Once the ultimate goes off, teammates can either finish him off, or Viper himself can Poison Attack him to death. Great for both support and killing. It should also be noted that Viper Strike's slow passes through magic immune units and BKB; this can be effective in taking down carries as the slow disrupts their DPS.

Level 1 - Poison Attack (1)
Level 2 - Nethertoxin (1)
Level 3 - Poison Attack (2)
Level 4 - Nethertoxin (2)
Level 5 - Poison Attack (3)
Level 6 - Viper Strike (1)
Level 7 - Poison Attack (4)
Level 8 - Nethertoxin (3)
Level 9 - Corrosive Skin (1)
Level 10 - Nethertoxin (4)
Level 11 - Viper Strike (2)
Level 12 - Corrosive Skin (2)
Level 13 - Corrosive Skin (3)
Level 14 - Corrosive Skin (4)
Level 15 - Stats
Level 16 - Viper Strike (3)
Level 17+ - Stats

Level 1 - Poison Attack (1)
Level 2 - Nethertoxin (1)
Level 3 - Poison Attack (2)
Level 4 - Corrosive Skin (1)
Level 5 - Poison Attack (3)
Level 6 - Viper Strike (1)
Level 7 - Corrosive Skin (2)
Level 8 - Nethertoxin (2)
Level 9 - Corrosive Skin (3)
Level 10 - Nethertoxin (3)
Level 11 - Viper Strike (2)
Level 12 - Corrosive Skin (4)
Level 13 - Nethertoxin (4)
Level 14 - Poison Attack (4)
Level 15 - Stats
Level 16 - Viper Strike (3)
Level 17+ - Stats

Justification: Poison Attack needs to be leveled to level 3 as soon as possible for effective ganking/harassing/chasing/killing purposes. Poison Attack at levels 1 and 2 have a horrendously long cooldown and low percentage of slow, which makes ganking very hard. Nethertoxin is the second skill to max out as the damage bonus helps Viper to kill quickly. Add Viper Strike at every possible level. As for Corrosive Skin and Stats, it depends highly on the situation that Viper is in.

Ask yourself: Do you have mana and HP problems? Go for Stats then. Although I highly doubt that mana will be a large problem for Viper, due to the fact that his skills do not really consume much mana. HP will pose the greater challenge for Viper. Stats can also be added to provide Viper with the Agility boost over Corrosive Skin.

Or do you want to kill faster/need defence against high damage magic nukes? Go for Corrosive Skin then. Corrosive Skin provides additional damage per second as well as magic reduction.

Starting items:

, (590 gold)

Justification: For map control. Due to Viper's low base movespeed, a boots of speed can be purchased first to avoid being harassed by other ranged heroes, or avoid ganks as best as possible. The tangos help to heal against damage taken.

x2, x2, (596 gold)

Justification: For last hitting and a slight damage boost for harassing. The bonus damage comes in handy to score last hits and getting farmed up quicker. Once again, the tangos are for healing purposes.

Early game:

x2, OR ,

Justification: The two slippers are built up into two Wraith Bands, giving a +18 boost to damage, as well as a slight increase in HP. The main question here is whether to get Power Treads or Phase Boots. Treads give Viper the much needed Agi/Str boost, both for attacking/survivability, as well as an increase in attack speed. The only bad thing about this option is that Viper really needs the extra movement speed. Phase boots, on the other hand, gives a 16% extra speed bonus through Phase and +24 damage. However, this option sacrifices the stat bonus.

It really depends on the situation you are in - are you having difficulties laning/constantly being ganked? Go for Treads if this is the situation you are in. If you have not much of a problem, and you want to farm better/kill faster/chase faster, go for Phase Boots.

Finally, the TP scroll is Viper's escape mechanism.

Core items:

/,

Justification: Being a carry, the damage and agility boost is much required. Lothar's Edge gives a +38 damage boost, +10 attack speed and Wind Walk. This is VERY important as Wind Walk becomes Viper's escape mechanism, as well as for ganking. The 150 backstab damage is very helpful in picking off low HP, solo heroes.

Other than Lothar, Manta Style is also a viable option due to the extra Agi and movement speed. Once Viper gets his core, his movement speed will not be that slow anymore. Mirror Image can also buy time for Viper to escape from ganks. Either one of these two items are essential in a carry Viper's core.

Monkey King Bar is also a core item as it provides Viper with a great damage boost, and it allows him to counter his weakness, TP Scrolls.

Late game items:



Justification: That's all. The huge Agility boost and evasion makes Butterfly the ultimate Agility hero carry weapon. Viper will morph into a fearsome carry with this item late game.

Luxury items:

, ,

Justification: The luxury items depends on the situation as well. Get a Heart of Tarrasque for survivability or an Orchid Malevolence to silence spellcasters/deal extra damage. The Critical Strike from Buriza multiplies your DPS by 1.375x, and +88 damage is a significant boost to your DPS as well.

Starting items:

x2, (550 gold)

Justification: The two gauntlets give a +6 boost to Strength, or 114 HP. These gauntlets can be later upgraded to Bracers or an Urn of Shadows. The Stout Shield provides some early game damage block, so as to increase survivability. Likewise, the Stout Shield is part of the core item, Vanguard.

Early game:

x2,

Justification: This is a build up from the two gauntlets that were purchased at the start of the game. In addition to the two bracers, Viper can opt to have Str treads to further boost his HP. The total HP addition from these items is 380, which is quite a fair bit. It shouldn't be hard to get Viper's HP above 1000 with these items.

Core items:

,

Justification: Two HP boosting items to make Viper tankier. Once Viper is able to get these two items, his HP should be around the 3000 HP mark. Yes, very fat indeed.

Late game items:

,

Justification: Butterfly has evasion which makes Viper even tankier. The main reason, however, of getting one of two of the above items is so that Viper does not lack in damage. Butterfly is the preferred choice, adding to Agi and providing evasion, but Monkey King Bar is not too bad as well, given that it has ministuns. I would say that the components of Monkey King Bar are slightly easier to farm than Butterfly. This is up to player preference.

Luxury items:



Justification: Even though Linken's Sphere is relatively cheaper as compared to the late game items, I classify it under luxury items. The main reason being that Viper will already have sufficient HP to resist against nukes and will have a high chance of getting away from ganks alive. Linken's Sphere will add on to the regeneration rates and help to negate spells. A good add on to Viper's existing core. There is nothing much that can be added on to Viper's late game item build, other than another Heart.

Starting items:

, , x3 (529 gold)

Justification: As a support Viper that is preferably laning with the carry, you need to buy wards. Good warding helps in avoiding ganks and providing map awareness. You can also buy the courier to fetch items for the carry. Finally, the branches give a minor stat boost, which can be upgraded later to a Magic Stick.

Early game:

, ,

Justification: Str Treads give Viper the HP boost to tank damage for the carry in the lane. The Magic Wand heals the Viper should he get injured and collects charges from spellcasters who harass him. Finally, the Urn of Shadows give Viper a further Str boost, increasing his HP, and allows him to heal his allies from the charges collected. Not too bad an option.

Core items:

, ,

Justification: Now you may ask, why Force Staff and Eul's Scepter of Divinity? I chose Force Staff over Dagger because it gives stats, can be used in and out of combat and most importantly, target allies. Force Staff can save your carry's life should he be ganked, leaving yourself behind to be killed.

The HP boost, AS boost and most importantly, the MS boost from Janggo are pretty good on Viper. Easy to farm as well.

Finally, Khadgar's Pipe is important as a Support Viper. The carry will usually be the target of spells in a teamfight, and Barrier comes in very well, protecting him against at least half the nukes.

Late game items:



Justification: Aghanim's Scepter decreases the cooldown of Viper's ultimate to 12 seconds and increases the casting range, giving Viper better harassing skills. The HP and mana boost come in handy as well.

Luxury items:



Justification: The standard Agility hero ultimate weapon. Helps in fast killing together with your carry.

Justification: Honestly speaking I wouldn't put this under situational, because every carry or tank Viper should get this in order to be so much more effective in teamfights. Hopelessly, your enemies just stare at you pick off the supports one by one without being affected at all. But to be fair, in games where you are already owning, or there are not many significant stuns/magic casters on the enemy team, you're better off spending that money on something else. (Thanks to deadlycrusher for pointing this out.)



Justification: Get Kelen's Dagger if you want mobility, map control and to pick solo heroes off. However, the dagger lacks stats which will affect your survivability. As compared to Force Staff, the dagger falls short of stats, but compensates with a low item cooldown and long blinking range. Your choice.



Justification: Ever since the orb effect has been taken away, Sange and Yasha has become a viable option for Viper. Get this only if you have problems farming, as each component is relatively cheap and the Agi/Str come in handy.



Justification: Get Vanguard if you have problems surviving in ganks or are facing heavy harassment. The HP boost and regeneration come in handy.



Justification: The Int and Str from Necronomicon gives Viper more mana, considering his mana intensive spamming, and additional HP. The summons from Necronomicon can provide harassing as well.



Justification: The lifesteal is very good from mid game onwards, if you can utilise orb switching effectively, then you can get this item.



Justification: Get Ring of Basilius if you have mana problems.



Justification: The core on all carry heroes. /lololol

, , ,
Most forms of orb effects. Viper, *in general, does not go well with items with orb effects. Viper's Poison Attack is very powerful and you will not want to override it with something else.

Eye of Skadi is an absolute rejection due to the fact that Viper's slow is greater than the slow from Eye of Skadi.

*I say in general because lifesteal and feedback can work with Viper, but it may be challenging. To utilize both Poison Attack and lifesteal together, you must toggle auto-cast to swtich between one orb and the other.

When auto-casted: Poison Attack
When manually casted: Lifesteal/Feedback
When not casted: Lifesteal/Feedback

Same goes for Critical Strike and Bash.

When auto-casted: Crit/Bash when it procs, Poison Attack when it does not
When manually casted: Poison Attack
When not casted: Crit/Bash chance

Here is the table for your reference:



*[1] If the item was acquired (bought, picked up, received) before the first level of the ability only the ability will work.

*[3] Only Feedback will work if the target unit can be affected by Feedback (Maximum Mana > 0 and not magic immune), else the other ability works normally.

*[6] If you got the item before leveling the skill, then you will not Bash or Crit. If you acquire the item after leveling the skill, it will override on Proc, but will still consume Mana and show the projectile.

The most common role of Viper. Here's what is important if you want to play as a Carry Viper:

[+] Good last-hitting skills (At least 65% of the time)
[+] Good harassing skills (Abuse your range and spam your Poison Attack)
[+] Knowing how to maintain creep equilibrium for maximised farming
[+] Knowing how to orbwalk
[+] Having a good support
[+] Knowing how to escape from ganks

A very viable option as well, the Tank Viper outlasts enemies in 1v1 situations, as well as taking the damage in teamfights and still being able to kill them. Here's what is important if you want to play as a Tank Viper:

[+] Moderate last-hitting skills (At least 50% of the time)
[+] Knowing how to orbwalk
[+] Having a good support
[+] Knowing how to initiate with his ultimate
[+] Knowing who to target first in teamfights
[+] Knowing when to escape from teamfights

A Support Viper is a more unique playstyle of Viper. This Viper supports allies by slowing enemies with his spells, and protecting them from nukes with his items. Here's what is important if you want to play as a Support Viper:

[+] Knowing how to let the carry get the last-hits (You should only last-hit about 20% of the time)
[+] Knowing who to target first in teamfights
[+] Knowing CLEARLY the effects of each item
[+] Knowing when to utilise each item
[+] Having good communication between the carry and you
[+] Knowing how to take the most damage so your carry can stay alive as long as possible

Viper has an attack range of 575, of which Poison Attack adds a further 25 on top of it, making that range 600.


Also, since Poison Attack is a spell, enemy creeps will not attack you when you harass the enemy. As such, try to move as far outward as possible to harass the enemy, ensuring that he gets nowhere near your creeps and cannot farm at all.

There will be scenarios where you are being chased back towards your base. If the enemy does not chase you until you die, they will inevitably turn around. You must always be prepared for this moment when they disengage and turn around. When they turn around, immediately land 2 to 3 Poison Attacks on them by orbwalking them/cancelling animation. This will reduce the gap in terms of damage exchanged, and make them regret ever chasing you.

In order to be a good Viper carry, you need to have good farming skills. One must know the mechanics of last hitting and farming in DotA.

Maintaining creep equilibrium helps alot in your farm. The lanes in DotA have an innate creep equilibrium; however, the slightest thing can change it. There are several ways to keep the creep equilibrium in your favour: Last hitting, creep blocking and creep pulling.

Last hitting:

Last hitting is basically when you land the killing blow on a creep, getting the gold from it. When you play Viper, here are the things that you need to know so that you can farm effectively:

[+] You need the health bars of the creeps to be on. This helps alot in estimating when to land the last blow.
[+] You need to know how much damage you do as a percentage of the creep's HP.
[+] You need to know how to cancel animation/time when to let your projectile go.
[+] You need to be able to predict denies from your opponent so you can last hit before/after his projectile hits the creep.
[+] You need good harassing to keep him away from the creeps while you farm.
[+] You need to know how to draw aggro so that you can farm (in some cases).[/nqb]

Creep blocking:

Creep blocking in mainly used in the beginning of the game to stall your own creeps from moving from the spawning point to the connecting point at the river. By stalling the creeps you move them closer to your side of the map, making you safer from ganks or attacks. Besides, you get an advantage over the enemy hero and creeps. When effectively executed, this allows you to attack your opponents without fear of being attacked. You now have the fog of war and evasion on your side. Everytime your enemy tries to attack you, he has a good chance of missing.

In order to block creeps, you should stand below the slope in front of the barracks.


To stall them you can keep walking directly in front of them, or you can also press "Stop" while continuously moving in front of them. This will cause your hero to stop for a split second, and the creeps behind you will be blocked and will fumble, trying to get around you. You should be pressing the “Stop” button as much as possible, without letting the creeps pass you.


Why is creep blocking good? If the enemy is ranged, he misses a lot on attacks because of the up-slope miss chance. If the enemy is melee, he cannot attack you without risking being attacked by the tower/draw aggro and take damage from creeps. This is the value of creep blocking.

Creep pulling:

Creep pulling relies on the mechanics of creep aggro. When you give the command to attack an enemy hero, the enemy creeps will switch their target to you. Note that spells do not draw creep aggro.

As a ranged hero, you can use this technique against melee heroes. Draw the creeps to your tower to help clear waves faster. The disadvantage about this is that you will have to tank some damage, both from the creeps and possibly the enemy hero. Also, if you fail to pull it off, you will take damage for nothing.

Some mechanics regarding creep aggro:

[+] Creep aggro effect is 500 distance from your position.
[+] Creep aggro lasts 2 seconds.
[+] The location of the Hero does not matter; you can click a hero accross the map, but if there are creeps within 500 distance of you, you will aggro them.
[+] The aggro occurs the moment you click the attack command, rather than when you actually attack them.
[+] Giving the attack command while outside of 500 creep range causes the moment of aggro to be triggered when you actually attack (again, the condition that creeps within 500 range applies).

The most important thing when ganking is to maintain distance from the target and ascertaining the safety of your environment (e.g. No potential dangers such as other enemy heroes/within tower range). Be careful not to go into his radius of sight too early. Close in when you are ready. Viper can initiate with Viper Strike for the damage over time and slow before orbwalking him to death. If you are confident, you can choose not to use your ulti and save it for other situations later.

Viper Strike at level 3 deals 725 damage over the whole time of the spell (544 damage after 25% hero spell damage reduction and has a 30 second cooldown. You can use it in situations whereby:

[+] The enemy HP is low and he has the ability to escape with invisibility/blink. Even if he does escape, the damage from Viper Strike will kill the enemy.
[+] You are in a 1v1 battle. Viper Strike can be used to help in killing your target faster.
[+] You need a slow. The 80% slow from Viper Strike at level 3 will definitely allow your teammates to catch up to the enemy, killing him.

Orbwalking is an micro control technique for attacking by issuing a new command after the point of actual attack. Doing it results in your hero not going through the aesthetic animation sequence after the the point you actually attacked, allowing your to utilize that time to do other things rather than stay stationary unnecessarily. The most common usage is to enhance chasing and kill.

In the case of Viper, his Poison Attack slows the enemy down. After the Poison Attack hits, move closer in and Poison Attack the enemy again. Repeat this attacking pattern as the enemy retreats. The slow from Poison Attack and the DPS gives Viper no problems in chasing down the enemy and killing him.

Here is a demonstration of Viper orbwalking the Spectre:

Healers:

Prevents you from dying in ganks, can support you while laning and helps you escape safely.

Invisibility Granters:

Another escape mechanism for Viper on top of his build.

TP Disruptors:

Basically any hero that can stun and prevent Viper's enemies from teleporting away while Viper is orbwalking him.

Burst nukers:

Due to Viper's generally low HP, nukes can kill Viper pretty quickly early and mid game.

Silencers/DPS:

These heroes make Viper's Poison Attack useless. By relying solely on his own DPS, Viper can potentially lose to other DPS heroes with a higher HP than his.

Fast chasers/Strong attackers:

These heroes can outrun Viper in the situation that Viper tries to escape from a gank or teamfight. As most of them are Strength heroes, they are pretty strong and have a good amount of HP, therefore being able to kill Viper in 1v1 situations easily early and mid game.

Mana Burners:

Mana burn makes Viper completely useless. Without his first skill, Viper can only rely on his normal attacks to kill (which won't be THAT painful or powerful early/mid game). If you're having troubles against mana burners, you can consider stocking up on a few clarities or perhaps a bottle.

Magic/Damage Immunity:
(Repel, Guardian Angel) (Nether Strike)

Magic immunity renders Viper's Poison Attack useless. Similar to mana burn, Viper can only rely on his normal attacks to kill enemy heroes. Omniknight's Repel allows him to safely run away from Viper's orbwalking process, and Guardian Angel just prevents him from dying. Barathrum can cast Nether Strike on you as you are orbwalking him to change the tide of the battle.