Not Updated For Current Season
well i decided to make this because the top rated guide here isnt that great. this is the best build ive found for lux thus far. you will have to understand that all builds are situational and i can only give you an all around build for her.
i get magic pen marks, pretty self explanatory there. i get the magic regen seals, also pretty self explanatory, due to how quickly lux can dump her mana in the early levels, so with a little discretion on spell usage you can last for a while without a mana pot or going back, especially if you have clarity. The glyphs are really a matter of preference. without the CDR, if you get the items i recommend, your CD on the laser is around 24 seconds. with them its about 20 so its really up to you whether you want the 4 seconds faster or if you want more AP. either way i suggest getting the by level glyphs because itll make you much better late game.
i get ghost because i like to be able to run away or get some where quick late game. this isnt necessary because lux has a snare, a slow, and a shield (yes that shield is actually useful sometimes). i also get clarity to be my game long mana pot. if i use my mana a little conservative i can make it on clarity alone throughout the whole game, in my lane. flash is a good alternative for lux for the same reason as ghost. if your laning with someone that has clarity or 2 people already have it and are locked in i like to get clairvoyance. its a great scouting tool to stop you from getting ganked, setting up a gank for an opposing jungeler, or if your laser and it are up at once throw the clairvoyance in the direction they are and get a better shot at them.
basic 9-0-21. there are some variations to what i have. if you like to run and grab blue buff get the monster buff extensions. similarly if you want to be more support for your team or if you know your laning with someone that runs low on mana often you can grab the clarity boost if you get clarity.
this is what i do and im not saying its the best out there but it works for me. i get the meki pen for the mana regen. i fill my inventory with items but you might want to leave 2 spots for more health pots and some wards, but the whole idea behind my item build is that i try and use money efficiently and effectively. example is that fiendish tome costs money to upgrade to but the only real benefit is the 20% CDR. id much rather get myself more AP or another item as needed until i need the inventory space for something else. maji's is also a good option but i dont get it when i solo queue because i dont trust my team enough when i dont know them.
i get her Q first because the snare is incredibly useful. it allows you to run away or grab someone thats running. the snare is really the only nice thing about the spell, its low damage and stays that way when you upgrade it so i feel all that upgrading it does is make you waste more mana for a snare. i then focus on getting her E maxed. its your farming spell and youll need the gold to be effective late game. eventually you will be able to hit the caster minions with it and hit them with a normal attack to kill them. as always when you can grab your R. youd be a moron not to. if your playing correctly, you will use that spell when you can maximize your damage, particularly when everyone is in a line of some sort or clumped next to each other. yes its nice to get kills but this is a team game and you should maximize your effectiveness, if you dont get a good chance like that use it to pick off runners. if you cant get a point into your E or R then you should get it in your W. the shield might seem pitiful, and it is at times, but with a handful of AP items it can stop a good 300+ damage on 1 pass. yes you can hit your allies twice for 600 damage absorption, not too bad... last up is to max your Q, like i said earlier i feel all that getting more into your Q is making you pay more for a snare so save it for last.
as i stated before its best if you maximize your effectiveness. hit enemies when they are in a line with your R and try and shield your team as best as you can. for easy ganks hit them with your Q and then throw your E in the obvious direction of retreat. this will snare them and then slow them down quite a bit, just blast it just as they are about to leave and hit them with a good amount of damage
although lux is squishy, not a lot of survivability, she can be a real difference maker with support and nuking capabilities. comment if you feel different i will explain my thinking on any of it if you ask and will consider any and all improvements.