Drow Ranger Concise Guide (NO CAPS LOCK)
When to pick:
Other team does not have Death prophet or Huskar.
Other team does not have loads of disables.
Other team is not made up of coward blinking or invisibility heroes.
Do not pick Drow Ranger if the other team fails to meet these criteria. A half-way decent Huskar is a pain to deal with. So are blinking and invisibility heroes or those with spammy nuke disables.
Itembuild:
You'll want to take the standard Salve and Tango combo as well as a Slipper of Agility, Circlet and an Iron Branch. This allows for an early Wraith Band without sacrificing decent stats out of the Fountain.
You'll want to go for Power Treads, set to Strength (red) when not farming and Agi (green) when farming. Manta Style is a must have for Drow Ranger, farm a Yasha then finish it by getting an Ultimate Orb and the recipe. Since the 6.75 patch, her ult has been buffed significantly and is very effective when paired with a Manta Style. Use Manta Style for tower pushing and to avoid targeted disables. If a Chaos knight for example, is trying to fling Chaos Bolt on you, he'll probably hit an illusion unless you have Frost Arrows on, then he'll just hit the one firing white arrows.
After you have a Manta Style, go for the usual Crystalys then Daedalus drill, don't forget to make a Helm of the Dominator for easier farming and because lifesteal on ranged carry. You'll also be able to build it into a Satanic later on if you desire.
-Starting-
Salve and Tangos
Slippers of Agility
Circlet
Iron Branch
-Early-
Power Treads
Yasha
Wraith Band
-Mid game-
Manta Style
Helm of the Dominator
Crystalys
-Late game-
Daedalus
Butterfly
Satanic
Skill build:
If you stack 2 or more Wraith Bands, get out. I know we all did this from time to time, but just don't.
Take Frost Arrows at level 1 and max them out by level 7. Take at least 1 level of Silence somewhere around level 4 and level Trueshot Aura alongside Frost Arrows. If you're being pummeled, take some stats instead of Trueshot Aura. Simple.
Laning:
Middle works fine, but side lanes work just as well. If you have a Pudge or Invoker on your team, let him mid or if you have a teammate that needs basic protection in a side lane. Drow Ranger in a side lane is first-blood and gank heaven.
If you take mid, remember to deny and farm last hits. Also, try to harass your lane opponent and check the runes. There's nothing worse than a mid Drow that doesn't gank a lane and just sits there and farms the whole game. Once you get your Power Treads, try leaving mid for a gank or push.
Mid game:
This is when you push in the outer towers and skirmish with the other team. You are a very vulnerable hero. No escape mechanism. You do have a 6 second silence so that helps to screw up initiations from the other team and prevent others from escaping and whatnot. Although you are soft, don't be afraid to take advantage of your massive DPS potential. When the time is right and your team is ready to get in the muck, don't hesitate yourself. Right click and silence everything. Your slows help keep runners from escaping and tanky bricks from getting close to you.
When not in a teamfight, go into hardcore farming mode. Think Anti-Mage's I FINISHED FARMING program. You need a Manta, you need a Daedalus. And if you just HAVE to, you may build a Shadow Blade. :/
Late game:
You're a walking death canon. Right click and silence, don't be afraid to get dirty and don't pussy out and let your push or teamfight go down the drain. If you're fighting really dangerous fights, reserve yourself slightly, you may be the only thing keeping the team up.
Allies:
Heroes with disables and slows, some of your worst enemies are people you want on your team. Frost Arrows and Silence plus any other slow or disable is a free kill.
Enemies: See opening "When to and not to pick" section.