
Sniper is a squishy ranged hard carry who uses his superior range to deal damage from afar. He is seldom picked in competitive Dota due to his squishiness, low base damage and high farming requirement, but he is a very popular pub hero.
Skills
Grad Headshot at level one to somewhat make up for the fact that your terrible base damage can make last hitting difficult.
Then alternate between leveling Headshot and Take Aim.
Always get Assassinate when you can (level 6, 11 and 16). Use it to secure kills on fleeing enemies; although the cooldown makes it spammable its mana cost is extremely high!
Maximise Shrapnel last unless you're in a pushing line-up, in which case max it early on. Use it for vision, AoE in small skirmishes, and on buildings during pushes.
Items
Starting Items: Tangos, Healing Salve, and three Branches (upgrade into a Magic Wand) OR two Slippers or Agility (upgrade into a Wraith Band).
Core Stealth Build: Power Treads, Shadow Blade.
Core Attack Speed Build: Hand of Midas, Power Treads, Mask of Madness or Maelstrom, and Drums of Endurance.
Core Safe Build: Power Treads or Phase Boots, Ring of Aquila, Drums of Endurance, and Yasha into Manta Style.
Luxury Items: Butterfly, Daedalus, Black King Bar, Monkey King Bar, Desolator, Satanic, Eye of Skadi.