I am Shheden, and this is my first guide so be gentle!:c I have played 1000 games league of legends and most of them has been as the adc in s2-s3. In the begining of s4 the adc roles has changed a little in my opinion but I've understood how to play again and now it feels just the same, the new masteries probably gave me that feeling buy never mind! At the first moment I bought Lucian and started playing I fell in love with his playstyle and kit, it's probably on of the best in the game. So know when we got that done with, this is my Lucian guide and I hope it will help you!

This guide is still in progress!

PROS
+ High mobility and low CD escape spell
+ Ult makes tons of dmg if well aimed
+ Really good Passive
+ Relentless Pursuit through walls
+ Pretty easy to win lane
+ Great partner with most supports

CONS
- Easy to play but hard to master
- Minions can be hit by The Culling and block it from hitting a champion.
- No CC
- Hard to get back in the game if you're behind alot

I use this rune-setup cause it provides Lifesteal, AD, MR and Armor!
2 Greater Quintessence of Life Steal so you can sustain in lane
1 Greater Quintessence of Attack Damage good for lasthitting and poking
9 Greater Mark of Attack Damage same as above ; good for lasthitting and poking
3 Greater Glyph of Mana Regeneration so you don't take that much damage from pokes in lane
6 Greater Glyph of Magic Resist so you can use your spells to farm and poke
9 Greater Seal of Armor so you can survive pokes

I split the quintessence cause I think 4% lifesteal + pots/dorans is enough to sustain in lane.
I use an AD quint instead of a third lifesteal quint cause I find it more use than putting a point in the mastery tree for the bonus damage for lasthitting/farming.

If you're pushed under turret there is two ways of farming it.
First: On casterminions you let the turret do one basic attack and then you kill it; if you don't deal enough damage to kill it you can hit it once before the turret shoots it or you synergize with your support/let YOUR minions deal some damage! On meleeminions you let the turret do two shots and then you finnish it.

The second way is: Just push back the wave as much as possible so its 50/50 asap. To do this you can use lucians Q and shoot the entire wave and then push it back.

When there are two minions with low health and you're choosing between getting the one to the left or the right, that's no problem for Lucian! You can simply Q or W the wave, you could also use an abiliti on something else and then use your passive, but don't forget. If you stand in the middle of a minionwave it will maybe shoot a random creep. But this is a skill that you can learn to become a better Lucian player!

If the creeps are in the middle of the lane its not much I can help you with, just understand how much you deal and try to farm as good as possible, if you're bad at farming create a botgame and farm, just farm to learn and understand Lucians damage and kit.

Here are the best support champions for Lucian. Since Lucian got no CC a support with CC is great. In my opinion these supports are the best:
Since Alistar is tanky,got great CC and a heal, I think he's a top support for any AD Carry. When alistar got some movement speed he can easily use Pulverize
and then Headbutt to knock them back or the fancy combo and knock them airborn.
Lulu is a great support because of her kit. Lulu is great because she can change her playstyle wery easily, she can decide between speedboosting you or an ally or an enemy who she will simply CC with Whimsy and Glitterlance. Not to mention but her ult is really great too!
Leona is a great support because of her CC and her passive Sunlight which makes you do even more damage! If Leona hits a full combo with ult she will stun the target for 3seconds which is ridiculous!
Janna is one of my favorite supports but many people underestimates her, she is really good with lucian. Her shield Eye of the Storm will shield Lucian and give him alot of AD, when it's at rank 5 its a free bloodthirster. It helps Lucian do free trades and makes his Q ( Piercing Light) deal even more. Jannas movespeed is also great because Lucian got one of the highest base movement speed of all AD carries.
Thresh is also a top support with any AD carry (except kog'maw)cause of his lantern that can save millions of lives every game. A well played Thresh is devastating for everyone. Let thresh poke while you farm and when he hits a Q ( Death Sentence) follow up with your spells and don't forget your passive and you got a kill or they must recall and you can push their turret or force dragon!

Deal as much damage possible WITHOUT taking damage!
People will prioritize you in fights and most likely try to dive you like any other AD Carry and because of that you need to pay lots of attention to your positioning and try not to get caught out, cause you got a really low healthpool & low armor/mr.
In a teamfight you want to stay safe and just deal tons of damage, poke around with your Q ( Piercing Light) and W ( Ardent Blaze) but save your E ( Relentless Pursuit) to escape, never use it to reach someone or to proc your passive in the middle of the fight cause it's your only escape tool except for flash! But it is OK to grab a kill at the end of a fight or to use it to get a better positioning, and never ever try to get their AD Carry who is behind their frontline cause that will result in death. Since Lucian is a great kiter you can easily kite anyone who dives you, use Relentless Pursuit and then your ultimate The Culling and just walk backwards.

I don't prioritize crit on Lucian, you could go full crit with Lucian as I do in my second guide but in my opinion these items are the best for Lucian!

Trinity Force is great because he can spam his spells with eze.
Blade of the Ruined King is great for selfpeeling against a fed riven or a diving cho'gath.
Statikk Shiv is good for the extra damage, MS, AS and little crit; the crit from statik and tri makes Lucian crit when he needs it.
Last Whisper is a great all-around item. It's good against tanks and carries - those who got armor and those who dont.
Berserker's Greaves I don't have to write anything here. The only thing I can think of is if its a really long game you could change out boots with PD but; homeguard or furor is a great reason to keep your boots.
A defensive item like Guardian Angel, Banshee's Veil, Frozen Mallet or Mercurial Scimitar are a great way to keep yourself alive versus bursters or high CC champs.

When you're in lane you need to prioritize farming/getting turret and kills; and if you can get dragon! Get your team grouped up and get it when their adc or apc recalled, even if their jungler is gone and they got no smite!
If you want to be able to carry> You need to have gold > You need to grab objectives and farm!
If you're going to recall and there is a giant wave of minions or there is comming a wave, take it by using your spells or ult the incomming wave so you don't miss out on gold.

At lv.1 you will mostly out-damage any AD Carry in the game, you maybe wont win a lv.1 trade but that mostly depends on the support, if you got a lv.1 Janna or a lv.1 Alistar.
When you've bought phage and got boots it's pretty simple to win a trade, just think twice before engaging or if you get engage, keep fighting it.
Every time check that there is no minions that can deal a ton of damage and make you lose the fight or if they do that misstake, abuse it! Also if there is a giant minion wave, farm it. Its much more worth to farm a wave of 10 creeps than to fight a fight and lose all that gold, I said it earlier but to be usefull mid-lategame you need your items, and to get your items you need gold. The more gold, the faster and the easier you'll be able to carry.
But if you're just going to trade damage, normally AA vs AA. Use your Q then and AA, by that you will use your passive and easily win that trade! When you got Sheen/ Trinity Force it will be much easier cause you will deal much more damage.

If you're going to poke while farming you can aim at the minion infront of them, you must stand in a line as I will show in the 'Abiliti chapter' which I will add soon. Otherwise you will totaly miss it.

In my opinion Lucian works great against any adc, but some are tuffer. If you're going to have a hard time or if you're playing against someone you think is harder ask your support to pick someone with CC ex Alistar, Neona or Nami. Supports that can poke,heal and CC the enemy are great if you're going to have trubble, so communicate with your support!

To be honest, there is no such thing as counters. There are harder champions and easier, you just need to understand their weak and strongpoints and how to defeat it.
Champions that counter Lucian are those who can dodge his ult and perhaps other spells or those who deal alot of damage early and doesnt give him a chance to farm.

*Sorry for not giving a detalied 'who counters who' list but it really depends on who is playing the champion.*~Peace~