Why Should I Play Lucian?
Because he was inspired by Equilibrium and The Matrix, two of the greatest action movies ever made. Lucian brings the art of the GunKata to The Fields of Justice, showing you why you should never leave home with one gun, when you can take two.
More tangible however, Lucian is an overall strong AD carry, capable of dealing surprising burst damage as well as being fairly mobile and hard to chase down or escape from. It's too early to determine where his optimal power lies, but it seems to be very spread out over the entire game, giving him few weak points.
Pros and Cons
+Powerful ADC at almost any level
+Has good mobility within his kit. Difficult to both chase down and escape from.
+One of the best passives in the game.
+Versatile, can play burst or sustained damage, can go mid or bot.
+Capable of a niche AP build, in case of emergency.
+While definitely not tanky, he has slightly more survivability than some other ADCs.
+Skills are fun to use and useful in many situations.
+Terrifying lane bully, can all in for a kill at level one with the right support.
+Strong farming and pushing
+Has a very wide pool of animations that are fun to watch and very fluid.
+He is based off of Gun-Fu, specifically GunKata from Equilibrium.
+Has an awesome voice.
-Is an ADC, and thus a priority target and cannot take many hits.
-Not very easy to get the grasp of compared to some other champions.
-Depending on how you do the items, he can be slightly weaker midgame. (though by no means useless)
-All of his kit can be dodged, and Q cannot be led to hit more easily.
-His ultimate is hard to use due to it's low damage and linear nature
-Assassins, as usual, wreck him. Lucian is unlikely to outburst them 1v1
-Average range (550)
-Low base movement speed
-Does not benefit as highly from attack speed as some, but his ultimate scales with it.
-Mana issues from hell
Before the game begins, there is always the matter of what to take with you. Above are my suggested Runes and Masteries. They are what I feel comfortable with, and I feel shore up some of his weak spots. The runes are a fairly standard set, taking a balance of early damage and penetration in offense (as Lucian lacks in level one damage) and similarly a mix of scaling and flat Magic Resist. The Quintessences are variable, I prefer move speed overall, especially if playing mid, as you will have to dodge skillshots and later on roam. I have not yet experimented with Lifesteal in bot lane.
Second, there is the matter of Summoner Spells, Flash and Barrier are very typical choices, especially on ADC. However, if you choose to go mid, Ghost or Teleport may be more useful to you instead of Barrier, play around and find out what fits for you.
Finally, you will need to know what Lucian does,
Passive: Lightslinger. On every ability cast, whether it hits a target or not, will grant Lucian a six second buff, with this buff his weapons will have a visible particle glow around them. Upon his next basic attack, he will fire twice. The second attack does slightly reduced damage to champions, 50% less at level one down to 25% less at level 18. This is an extremely powerful passive, both at early and late stages of the game. While it is still useful midgame, it is unlikely to be a major source of damage until you get a couple items. This passive is considered to be two separate basic attacks, and each will proc on hit effects and can critically strike. Moreover, if the first shot of a Lightslinger kills it's target, the second may find a new target, the parameters that this works under are unknown. Lightslinger benefits heavily from cooldown reduction and critical strike, which is what inspired this alternative build.
Q Skill: Piercing Light. Lucian's Q is a short ranged targeted ability, though short range is somewhat misleading, rather the targeting is short range. On cast, Lucian prepares for a brief period of time and the area lights up, after finishing the 0.35 second channel, a laser beam, similar to Lux's Final Spark, though over a shorter range. The laser is about twice the actual cast range, and deals full damage over it's length. This skill does 25% less damage to minions, in spite of this, it is a powerful pushing skill in combo with Lightslinger. Very good skill to take at level one, but see the next skill for more details on the first skill to take. As this skill ranks up, it increases in it's Attack Damage scaling, as a result, this is almost always the best skill to max by level nine. The cooldown is the shortest of all of his skills, and makes this skill a good source of damage and Lightslinger procs. The skill is not a very good poke though, unless there are minions around, because of it's short targeting range, if there are minions, it can be useful to poke by targeting the minions and trying to line up the attack with an enemy champion, after this it is usually best to use the Lightslinger for continued harass. This skill is a very good trade early on in combo with Lightslinger, and lends a lot of early game power to Lucian.
W Skill: Ardent Blaze. Ardent Blaze is a skillshot ability that fires a moderately sized projectile, upon either contacting an enemy or reaching the end of it's range, it explodes in a cross shaped pattern. The pattern is not fixed, the explosion is always perpendicular to Lucian. As with Q, the explosion deals full damage at every point. This is similarly a good harass if an enemy is hugging their minions, as the explosion may go straight through the minion to hit an enemy champion. Ardent Blaze is Lucian's main untargeted harass, making it very useful in lane, provided there is mana available and the cooldown will not be a hindrance in the immediate future. Ardent Blaze applies a debuff to everything hit by it, this debuff does nothing on it's own, but when Lucian hits an enemy affected by the debuff he gains movement speed, making this an excellent skill for chasing, kiting, or fleeing. As with Q, the Lightslinger proc afterward makes for excellent damage to your opponent in lane. The extra movement speed also allows you to easily chase in for the kill. An ideal harass or even kill combo in lane would be Ardent blaze – Basic attack – Piercing Light – Autoattack, this burst is extremely high for an ADC and shows Lucian's lane bully tendencies.
E Skill: Relentless Pursuit. Relentless Pursuit is an untargeted dash in any direction. Great for repositioning, escape, or, as the name implies, pursuit. As with all other skills, you get a double shot from Lightslinger right afterward, the increased damage from Lightslinger and mobility makes it very similar to Vayne's Tumble. Though on a longer cooldown and with the ability to crit twice. In addition, Relentless Pursuit, unlike Tumble, can cross thin walls. Relentless pursuit has another effect however, on cast, all slows are removed from Lucian, like a mini cleanse, allowing for excellent escapes or resisting certain escape methods. Be warned it removes slows on cast, not at the end, so do not try to dash through slows as it may fail, wait to be slowed before removing it and hitting your Lightslinger.
R Skill: The Culling. Lucian's ultimate skill is a moderate ranged series of skillshots in one direction over three seconds. Upon cast, Lucian will begin firing the shots in the direction indicated at a continuous pace, for the three seconds the ability is active, you may use Relentless Pursuit, Ghost, or Flash. In addition, if you get a kill while The Culling is active (not necessarily from one of the shots itself, a kill from ignite for example will also trigger this effect) the cooldown of Relentless Pursuit will be reset, allowing you to hypothetically chain dashes to chase down a group of low health opponents. The Culling is actually a low effective damage ultimate, once the series begins, Lucian cannot change the direction, though he may cancel the skill, and you can only use lateral movement to keep pelting your target. The number of shots fired by The Culling is derived from Lucian's attack speed, up to a cap of 34 shots at max rank of the skill with 2.5 attack speed. The damage from each shot scales mildly with attack damage and ability power, but is individually low. The Culling will get covered more in strategies.