Early Game      

Pros-

Very good hero killer during the entire game
Has great lane control because of poison sting
Not that hard to use
His slow is great in ganks

Cons-

Low strenght gain which results in low hp
No simple escape skill
May become the prime target after a few kills

GAME START

Ok lets begin, I usually choose a lane with a low hp melee hero such as an agility hero like juggy/phantom lancer if I come out of my base after the creeps arrive but usually if I am sentinel I go bottom and if I scourge I go top but if it is possible for me to get the money for my perseverance e.g 2v2 I will do the opposite so that I am close to the respected secret shops. You could simple start the game off with a ring of regen which you will sell later when getting your ring of health, some tangos in case you go imto a lane with a hero like zues/lina. However you may not be the one using the tangos, a couple circlets for your bracers could be good also.

LANE SITUATIONS

1 melee hero- well this is what you are hoping for because here is where you harass the hell out of your opponent and thus make him use his tangos/return home to heal/be afraid to come forward to last hit. I will explain later.

1 ranged hero- well according to who it is you can do the same harrassment as before or you could simply play nice and last hit and deny as usual. It is all up to you.

2 melee heroes- this equals twice the fun as before but beware of heroes with stuns such as leoric/sven becuase you are very frail at this point in time and if you dont start with a boots of speed it gets a little more dangerous when facing heroes with stuns. As a viper this early in the game a 4second stun is not a good thing. However if this is not the case then you can be aggressive and harass people with your poison sting.

2 ranged heroes- Just be careful and do the usual last hit and deny techniques as always unless you cant help but harass the hell out of those 2 heroes to increase your lane control.

LANE CONTROL

I mentioned before that viper has great lane control and this is so because of your autocast ability poison sting, this skill is related to the other autocast abilities such as frost arrows,silencer’s glaive atk and others. Since you have no nuke ability then this becomes your nuke you can simply press ‘c’ which is the hot key for it and click on a hero in range. This is mostly done against melee heroes and this will give you the lane control you want. A good time to do this is when the hero is approching for a last hit, when you do this then it means that the hero would have to pay with his hp for a last hit and because of that he may advance forward less.

ENDING INVENTORY

                
     Boots of Speed         Perseverance    
                
     Bracer         Bracer