IMO sniper is a fun to play hero but its quite frustrating playing with him in publics and seeing other players doing bad with him thus calling the hero bad.
Sniper needs to be played smart to be effective altho this aint quite hard once you get into it.
This guide shows how i feel like playing Sniper, and I've had good results so far, i highly recommend playing him with friends in a team only tho.
From my PoV i can tell that Sniper is a solid pick when:
-The enemy has no mobility hero like Void who can kill you easily
-The enemy has low-ranged nukers which are easy to kill
-The enemy is using a Push-Team
-Your team consists of a good initiator and additional disable that can save your ***
-You know that you'll be able to farm alot
If some of those above are not met, it's not a good idea to pick him. Sniper is easy farm for heroes like Pudge,Bloodseeker,competent Linas and so on, not like you can't handle it but its risky.
-Good dps if given farm and the safety
-Easy to push lanes and especially towers due to outrange
-Easy to farm with him
-Annoying for channelers to face him, same for invisible heroes during a teamfight
-AoE slow in a teamfight almost spamable
-Long ranged pickup nuke
-Squishy as hell
-Useless without alot of farm
-Rather difficult to gank with him if wards are in place
-F***ed without a good team that supports him
he still remains one of my favourites and i hope to see him in the meta someday! :)
I use the same skillbuild everytime i play Sniper, this one feels to be the msot comfortable one for me. Maxing Take Aim is a must since it gives you the needed advantage in terms of range which does indirectly boost your lanepresence and helps you survive in a lane due to no harrassment towards you in most cases, it also helps you to position in teamfights so going for you will put the enemy in a less-favourable position.
I max Headshot out last because i feel like it is bad to have early on, don't get me wrong it is a good talent but you won't be able to benefit from it unless you got some decent AS already.
Since the ministun stays at a solid 0.25 it helps getting a few extra attacks if you are good enough at strafing so it kinda does its job already. Its bad to skill this up early in a lane if you ask me because you wont be able to hit people alot, after a few hits most brained players will just retreat/outrange you and try to set up a gank to regain their lane.
Now onto Shrapnel, this skill rocks! I can't tell how often this is getting skipped because they think its useless due to "low" damage and it eats snipers already low manapool.
The vision it grants is a nice feature and it managed to help me set up good teamfights already.
Most importantly is the slow, up to 30% AoE at a 1800casting range is sick, you can pick up fleeing heroes, use the sight to ultimate em too or just to harrass them in a lane while going for a kill. I won't do any math here because 20x5 should be known by anyone xd.
Make sure to use this skill where your enemy WILL go, not where he stands, incase you want to kill somebody and not scout. While this spell is a decent farmingtool i rather not use it to kill creepwaves.
This also is a nice tool to counter my most hated hero, furion :), you can easily get rid of his pushes if he ain't with a team and you are certain you wont die in a second.
Assassination, not much to say. His ultimate is a nice long ranged nuke to kill fleeing heroes out of a teamfight or perhaps some nice ranged combos like rndstun+stunstrike+assassination. Since it grants vision of your target this is an excellent skill to give your team vision on an important target during a teamfight to make sure your spells will land.
The 2 listed itembuilds used by me both got good dps and focus on certain games.
I like using treads+manta+maelstrom if i face high hp heroes or generally tanky heroes like Axe,Dragon Knight etc. You'll do alot of dps due to headshot procs,lightningprocs and a very high AS, this build is bad if you like high numbers tho.
Phase+shadowblade+daedulus is usually used when facing heroes like Invoker,Rhasta etc or squishy carries to nuke them down fast and take advantage of their low healthpool. While i dislike shadowblade in general it helps you survive due to no collision and 20%more ms assuming your team is competent enough, the extraburst also helps alot. Manta is too expensive in this build so this'll do too. It makes the enemy buy dust more often and thats a potential goldloss :).
In both builds i go for Skadi once i finished my "end"game item because you'll lack HP as always. It won't just boost your hp to near 2k if not more but the slow is very good on sniper. With this item you won't be punished that hard if you end up being at the front for some time and your mana also is near infinite for the duration you'll spend on the map. It's one of my favourites so feel free to replace it altho the games wont last that long usually.
Any item afterwards this is your choice since i've never had a game where this really happened. Since Headshot is an inbuild MKB this item usually has less priority for me.
Stay in a safe lane and farm farm farm. If you get the chance try to take a kill with some disabler, your range and headshot procs on lv1 will pretty much grant you freekills if setup proberly, your ultimate also is a great finisher which almost always gives a kill to opponents below lv8.
You still farm as much as you can, but dont be afraid to go into a teamfight because your slow and your ultimate contribute alot compared to other carries!
You can go into the jungle or kite ancients for some extragold if the lanes are too dangerous.
You are the man for pushing and defending lanes np with your range, you can camp behind towers and finish waves off really fast. Also Shrapnel on towers, especially t3towers, is annoying for the enemy and breaks turtle strategys after a while.
This is my first guide and I still have to figure out this guide, but i hope i can help some people with this and they'll improve on their Sniper! :)