Sorry at first for not replying (have been busy with my studies).

Thanks for your feedback. I will give this guide some overwork (probably) over the next week, by adding different builds and review the structure of the guide as such (I posted the guide 1 day before mobafire added the new style stuff -.-).

Good build, I disagree with one section "5.4" which also adds something to your items section. Nashor's Tooth is a very good Lux item, even though it has AS it also gives you CDR and AP, and a little AS for those Illuminations never hurt anyone.

why have so many people thumbed down! This is an amazing guide and your explanations are Extremely thorough. Not to mention it took me 20minutes to read the whole thing. (<- example of how thorough you are) i love lux and have never been to good with her. So i tried out the top guide Annnnd well tho the survivability was great, my damage output sucked. So i went down the list and got to yours. Where i went 15-1-14 and had no complaints. great guide man +1

Very beatifull build. With full build i got all champs in 1 combo ^^
Q, E, R and DIE **********ER DIE!!

I persoanlly play a defensive/aggro version of Lux. I use coodlown, mana regen, and magic pen runes.(cooldown by level) My masteries normally include clarity and ignite, clarity because i've found myself in too many situations to count where i need 100 more mana for the kill, and ignite to help knock a bit off those tankier opponents. NEVER get the mejai's unless you are doing excellent, and ONLY get the rod of ages/ryali's if they have a tankier team. With the runes i have,(only primaries) my ult is down to 24 secs at lvl 18 with a glacial shroud. I also normlly wait until i have my ult to get the shield, as you need the firepower for early game kills.

Consider replacing Mejai's, it's not a stable item in ranked play; rushing Rabadon's also gives you the max efficiency (considering you don't need survivability) for AP - I recommend Catalyst into Rabadon's.

Good and thorough guide.

I main lux with a slightly diff build that's alot less agressive, being pure support until 40+ minutes into the game. Never run out of mana with her unless hardcore harassing which is a slightly bad idea unless your enemies aren't cautious and you have good CC. Mejai's seems like a good idea for damage but i typically skip it and go for late game spell penetration. Earlygame Survivability. Also i don't think Rylai's is that great on her. I understand its effect and all but if your team is doing it's job as well, the slow from your E, and the supress from your Q should be enough to hurt them down, and to finish off anyone that no one can catch with R (or team fight hit with it) Of course my build is Sorc Boots - ROA - ROA - Void Staff - Survivability Item - Rabadon's Deathcap.

It seems like a weak build, since the 2nd RoA is really enemy dependant, but it gives you limitless mana, great HP and survivability, 60% spell pen and more. Though from reading your build i might switch to perminantly getting an early Tears for an Archangel since after thinking about it while writing this overly long message did i consider it being a much better idea for damage output (though i seem to hit 30 second lazer beams for 800-1200 with my style... your's will probably make it much higher :P)

found a few "flaws", 1. Dont take ignite, i know it could get u a kill, but its not ur job to get kills, its ur job to get assists, and u never wanna steal / take a kill from the physical carry, might wanna pack flash or clarity instead, i've seen lux's do great with clarity early game.

This might work in very low elo normal games, but it wont work against competent people that know not to focus the tank, not gonna leave a rating untill u do something about it

Thanks for you feedback though. Can't harm to overthink some choices :)

@mist: While it is true in your scenario that the further reduction of Light Binding's Cooldown (gained with more Levels) helps in shutting down chasers, I see the main area of field when to use Prismatic Barrier not to survive from being chased but to lower the damage input on your team in teamfights. Shielding your whole team (ideally) takes away great damage from Area of Effect spells, helping you to win a teamfight in the first place and (hopefully) don't end up being chased at all. Sure, you need to lesser Cooldown on Light Binding to engage your enemy more frequent, but thats the reason I tend to iterate between Light Binding and Prismatic Barrier in most (not all) games. It all depends on how the game is going, whether it's a game where the teams start to gather up early (in which case Prismatic Barrier and Light Binding will be skilled in an iterating order) or it's one of those game where both teams drag the teamfight to late mid game (in which case I'd prefer to delay Prismatic Barrier).

I've found the CDR boots not that great on Lux, since I frequently get the Golem Buff. However if you pass on getting the buff for your teammate they are a viable choice.

@Shm0: The problem is that you never know how long a game will last. A fully charged scepter is very strong. But I generally agree with you which is why I get Rod before Archangels in addition to the other two reasons (survivability boost in mid game and rather low manapool so the Archangels passive won't be that great). It's all about personal judgement anyway.
I have to disagree on the rune thing with you though. Of course HP helps you to survive longer (even if its just a hit or two) under enemy fire which buys time for further actions (a mate comming by/cooldown running off/fulfill castanimation/a DoT expiring). The games where I got significant mana problems were very rare which made me never want Manaregeneration runes. Of course your playstyle and the game situation have a huge impact on how you need or may not need manaregeneration.
As said in the guide text, if you need more manalasting capacities I'd advise you to get Clarity (also boosts you mates mana) over Ignite and if you need an escape mechanism get Flash or Ghost.
If you add up all those rune regeneration you'll get 16,2 / 5sec at level 18. Clarity on level 18 gives you exactly 700 Mana resulting in a total 19,44 / 5sec (((160 +30*18)/180)*5) for your alone. Considering that Clarity fills up the Mana of your mates by the same amount (skill it if you got it) its the much better choice then getting the runes.

getting rod of ages end game is pretty much useless since it takes 20 mins to max out and there is much better items to get at this point.

Also, vitality runes? 180 extra hp will not help you escape death - it's better to get mana regen for this.

Good work tho. :)

good detailed guide, though I tend to go archangels first as well - mana & regen makes a huge difference for me early game. I also try to work in some cooldown reduction, as that can make a massive difference late game (excited for the new CR boots!) I usually build Lux to save the PB until late game, maxing snare & lucent first. Being able to effectively deter chasers has saved me many more times than defending 50-100 damage.

GOOD STUFF!