One of the most important things in the game is farming. It's an easy and safe way to get items and carry the game. You can see more about wave management in the bottom of the guide, so you can help you adc get more farm.^^

Other things that might help you climb:
Focus on your own mistakes not your teams mistakes
Don't use the chat, it will only distract you
If you die a lot then buy more pink wards to prevent ganks and look at the minimap more often to see if you can find the enemy jungler. If you see the enemy jungler topside, you can play aggressive without the risk of getting ganked.

Hello guys this is my Lux guide. I have been playing since season 2 and have been Challenger the last 4 seasons. I have played every single Champion in League of Legends and Lux have been one of my favorite Champions back in the days. I got 2 accounts in Challenger at the moment and I'm trying to get my 3. smurf to Challenger. Right now I focus only on toplane where I play Tryndamere most of the time. You can join my stream if you want, would love that^^ https://www.twitch.tv/kurtdenstore21. There are many Lux supports in high elo, so even if I play Tryndamere you can still watch some high elo supports play and learn from them. Lux is actually the support with highest winrate atm, so go test her out in soloq before she gets a nerf!

My Lux build is situational you could use this build every game, but I would recommend you to form your own builds. Take some games with Lux and figure out what items you like the most.

This is my Challenger accounts

This is my greatest winstreak of all time in ranked

This is 2 of my smurfs

The items are situational there are many builds out there that works. The build and runes plays around your shielding power early. You are still going to deal a lot of damage late game.

Spellthief's Edge: Spellthief's Edge is your start item. You only pay 400 gold and you get Ability Power, Gold Generation and Base Mana Regeneration. And you get an unique passive that's called Tribute - This passive gives you extra damage and gold everytime you hit a champ or turret. It can only occur up to 3 times every 30 seconds though. You upgrade this item to Frostfang on your first back if you can. With the Spellthief's Edge you buy 2 Health Potions and a a free ward. The Health Potions let you stay in lane longer and this helps you get more gold and XP. The ward helps you spot the enemy jungle so you don't get ganked and killed.

Boots of Mobility: So after you get Frostfang, you should get Boots of Mobility. These shoes help you to land skillshots because you are faster and are able to catch enemies easier. They also help you if you find an opportunity to fast roam mid and gank.

Athene's Unholy Graile: Your first item is Athene's Unholy Grail. If you can't buy it directly you should get an Amplifying Tome if you got 435 gold. If you have 900 gold when you go back get Fiendish Codex. If you got 1700 gold you should get Fiendish Codex and Charlice of Harmony. But the ideal back is to have 2250 gold, then you are able to buy Athene's Unholy Grail directly. This item gives you more ability power, Cooldown Reduction, Magic Resistance and Mana Regeneration - So many great stats for Lux. You also get a passive that let you heal your teammates with your Shielding ability Prismatic Barrier.

Ardent Censer: After your Sorcerer's Shoes its time to get Ardent Censer. If you have 2300 gold after your boots you should back and get this item. If you back before you have 2300 gold you could get Amplifying tome if you got 435 gold, if you have 850 gold get Aether Wisp and if you got 1700 gold you should buy the Aether Wisp and Forbidden Idol. The most ideal thing is to get Ardent Censer directly though. Arden Censer gives you more Ability Power, Cooldown Reduction, Mana Regeneration, more movement speed and when you shield an allied champion he gets more attack speed and on-hit magic damage. Your shield also gets 10% bigger.

Morellonomicon : Now we want to get Morellonomicon. This item got some pretty good stats for lux - you get more Ability Power(I love that on lux hehe), more Health and some magic penetration. The Health helps you survive longer and the magic penetration helps you deal more damage even if they stack magic resist. The ideal back would be with 3000 gold, because then you are able to get the item directly. However sometimes you have to go back sooner to get Pinkwards or just to get more Health back. If you go back and have 850 gold you should get Blasting Wand, if you get back and have 1600 gold you should get Oblivion Orb. If you get back with 2450 gold you should get the Blasting Wand and an Oblivian Orb.

REMNANT OF THE WATCHERS: Now we want to get Remnat of the Watchers, you already have Frostfang from earlier - That means you only need to have 950 gold to get this item. You could get this item earlier in the game depends on your playstyle. I like to get Arthene's Unholy Grail, Ardent Censer and Morellonomicon before the item, because then you got strong Shields and a good amount of damage from your spells. The Remnant gives you Ability Power, Cooldown Reduction, Gold Generation, Health and Mana Regenaration. And one of the most important things it gives you wards every time you recall. Remember to buy Pinkwards whenever you can!

Rabadon's Deathcap: The last item is Rabadon's Deathcap. Get the item when you have 3600 gold if you can otherwise get 2 Needlessly Large Rods if you get back with less gold. Rabadon's Deathcap gives you a huge amount of Ability Power. So the enemy team have to be real careful around you after this item, unless they want to get bursted down by your full combo^^.

After your support item you could go full ap and just burst the enemy. You could build her like a mid champ that want to carry the game. If you get fed early you could try to build a mejas soulstealer and focus on staying alive and getting kills. After mejas soulstealer go straight to Ludens echo and follow that up with some other ap items that can help you snowball and carry the game. However you should go support items most of the time, its only if you get an amazing early game with many kills that the full ap strat works.

SUMMONER SPELLS - FLASH: Lux should have flash every game because it helps secure kills, help your adc or survive ganks. In teamfights you might be able to bait people to attack you and then flash away. That could lead to overextending from the enemy team. IGNITE: I take Ignite to have more pressure in lane, and you have way more kill potential. It also gives them grievous wounds and it helps killing ADCs and APCs easier. EXHAUST: I would always go ignite on Lux but it is situational, if you like to play with exhaust its still a viable choice. If enemy team got a fed Rengar exhaust might be the difference for a dead or alive adc.

Live forever Resolve: The Resolve rune helps Lux stay alive and you get pretty tanky by using these runes. Keystone Aftershock: The aftershock helps you with burst damage and then you are able make some risky plays without fearing death. If the enemy focus you and your adc is able to hit them at the same time, that should make you win the 2v2 easy. Aftershock proc after you hit your q ability and then you increase your Armor and Magic Resist by 70 + 50% of your Bonus Resists for 2.5 seconds. Shield Bash Shield Bash: The second rune in the Resolve path is Shield Bash - while using your shield on lux you get extra armor and magic resist with this rune. Your basic attack also deal more damage against a champion. The empowered attack lasts up to 2 seconds after the shield expires. Bone Plating Bone Plating: The third rune is Bone Plating. Bone Plating protects you from burst damage every 45 seconds. After Lux takes damage from an enemy champion the next 3 spells or attacks Lux receives deal 30-60 less damage. Revitalize Revitalize: The fourth rune in the Resolve path is Revitalize. This rune makes your shields stronger on yourself and your teammates. It also makes healing stronger and that means your Arthene's Unholy Grail heals even more^^ You also heal yourself more with Taste of Blood because of this rune. Domination Domination: I take Domination to get more sustain, that means we can stay in lane longer and I take it because of the extra out of Combat Movement Speed that helps with roams. Taste of Blood Taste of Blood: The first rune in the Domination path is Taste of Blood, this rune heals Lux when she damages enemy Champions it got a Cooldown for 20 seconds though. Relentless Hunter Relentless Hunter: The second rune in Domination is Relentless Hunter. This rune gives you out of combat Movement Speed, which is going to help Lux hit her Abilities easier. The extra out of Combat Movement Speed also helps with roams.

PASSIVE ABILITY

Illumination (Passive): Lux's damaging spells charge the target with energy for 6 seconds. Lux's next attack ignites the energy, dealing bonus magic damage (depending on Lux's level) to the target.)

Q

Light Binding (Q): Lux releases a sphere of light that binds and deals damage to up to two enemy units. Fires a ball of light, rooting up to two enemies for 2 seconds and dealing 70/115/160/205/250 (+70% Ability Power) magic damage to each.

W

Prismatic Barrier (W): Lux throws her wand and bends the light around any friendly target it touches, protecting them from enemy damage. Throws Lux's wand in target direction, shielding her and all allied Champions it touches from 50/75/100/125/150 (+20% Ability Power) damage for 2.5 seconds. Upon reaching its destination, it returns to Lux, stacking the effect.

E

Lucent Singularity (E): Fires an anomaly of twisted light to an area, which slows nearby enemies. Lux can detonate it to damage enemies in the area of effect. Creates a zone that slows enemies by 25/30/35/40/45%. After 5 seconds the zone detonates dealing 60/105/150/195/240 (+60% Ability Power) magic damage.Activate again to detonate early.

R

Final Spark (R): After gathering energy, Lux fires a beam of light that deals damage to all targets in the area. If Final Spark helps take down a champion, part of its cooldown is refunded. In addition, triggers Lux's passive ability and refreshes the Illumination debuff duration. Fires a dazzling ray of light dealing magic damage to all enemies in a line. Final Spark ignites and refreshes the Illumination debuff.

I would recommend you to study this video because wave management/Minion Control is one of the most important skills in the game. If you master this you will climb! I know you are the support, but you can still help your adc controlling the minion wave.

“The light inside is what makes me different, and I’m always careful where I shine it.”

~ Lux
Luxanna Crownguard hails from Demacia, an insular realm where magical abilities are viewed with fear and suspicion. Able to bend light to her will, she grew up dreading discovery and exile, and was forced to keep her power secret in order to preserve her family’s noble status. Nonetheless, Lux’s optimism and resilience have led her to embrace her unique talents, and she now seeks to bring greater tolerance and understanding to her homeland.

If you want to read the rest of the lore go to this page. https://universe.leagueoflegends.com/en_US/story/champion/lux/

Thanks for reading my guide, have a great day!