The Ionians have developed some of the most breathtaking and deadly martial arts on all of Runeterra - just one manifestation of their pursuit of enlightenment. The most remarkable blade style to emerge, however, was the unusual byproduct of foreign intervention. Master Lito was a swordsman whose teachings were sought by ruling classes from nearly every city-state. His art was a highly-guarded secret, but it was said that swords would breathe in his grasp. He withered unexpectedly from a mysterious disease which baffled the brightest of Runeterran physicians. When he died, he left behind Zelos and Irelia, his son and daughter, and a truly unique weapon. Zelos became a sergeant in the Ionian military and left to seek assistance from Demacia immediately prior to Noxus' invasion of Ionia. Irelia, charged with the protection of their home until Zelos returned, was alone when the Noxian forces struck.

The Ionians fought admirably, but soon Ionian blood stained the land beneath the prints of foreign boots. At the Great Stand of the Placidium, Ionians prepared for surrender, but were inspired to maintain their resistance when the young Irelia lifted her father's enormous blade and pledged to hold until her brother returned. In the chaos of the ensuing fight, Irelia was cursed with dark Noxian Necromancy. As her life ebbed, Soraka, the Starchild, made a final attempt to anchor her fading soul. Unwilling to relinquish her home, Irelia rose at the brink of death, and her father's sword lifted in the air alongside her. Irelia rushed back to the fore, unfazed by the blade's sudden animation. The weapon danced around her effortlessly, cutting down Noxians as they gaped in horror. The decimated invaders were forced to retreat from the Placidium. Irelia was appointed Ionia's Captain of the Guard, and when the defense of her homeland moved to the Fields of Justice, so did she.

'The sword flourishes, as though painting with blood.'
- Taken from a Noxian Field Report

*Note: Guide is WIP at this moment. This note will be removed upon completion.

Irelia is a fairly balanced champion, but your build highly depends on your team comp and the enemy comp. However, the most prevalent build I've seen in high-ELO play is a tanky Irelia. Reginald from Team SoloMid currently uses Irelia, and from watching his multitude of videos as well trying it myself with good results (my first game used his build, 6/2/10 @ 26mins), I thought I'd basically make the guide for him. However, most definitely feel free to replace any items.

Also, I have included my friend's recommendations, though I have not tried it yet, and will not provide any explanation.

Pros:
+ Versatility and balance
+ Very good champ even in Low HP situations (due to Equilibrium Strike stun)
+ Good burst

Cons:
- You WILL get focused if you initiate
- Garen (or any other champ with an execute skill) will cramp your low HP style.
- Exhaust or any other healing/damage reduction hits will effectively make your lifesteal R useless

Starting Items
- Doran's Shield is excellent if you are laning duo, 1v2, or jungling, and feel confident with harassing the enemy. It gives you enough health to push.
- Cloth Armor + 5 Health Potions guarantees a Heart of Gold if you are laning 1v1.

Early Game
- Grabbing Boots is your first priority. As a melee champ, being able to chase and/or flee faster is a plus. This will be upgraded to Merc Treads 99% of the time, as your passive is just asking to get stacked kinda like how you want to stack dodge on Jax's Counter Strike with a Ninja Tabi.
- Heart of Gold gives you great armor plus a gold bonus. Irelia relies heavily on her item build in addition to pre-game setup.
- You always want an early Sheen for your Bladesurge proc.
- The next item depends on your situation. If you are getting focused by DPS early, grab a Phage first to beef up. If you are getting hit hard by AP champs, grab a Kindlegem > Spirit Visage.
- ALWAYS grab potions. It allows you to push a lane more aggressively. Chug one if you are about to start aggressive play like 1v2 or a tower dive.

Mid Game
- Grab Trinity Force right away, as Zeal provides minimum benefits, and you may not even have room.
- Finish up your Randuin's Omen, grabbing Warden's Mail on the way there.

Early Game
- Irelia is an excellent 1v1 lane character. Even against Ashe and Corki, you will be able to harass them, and possibly deny them of both XP and last hits. If you have to lane 1v2, play with less chase, but keep one of them denied of XP and LH.
- Save your mana for harass and double LH (as in you autoattack one, and when you see another about to get hit, Bladesurge to LH it).
- Your harass will always be Q -> E. Hit W only if you are going for the kill.
- In high-ELO play, Level 1 Golem fights are common, but you could probably make it work if they have a jungler. For this, level Equilibrium Strike first.
- Keep some pots with you when you play aggressive.

Mid Game
- This is where Irelia shines. If you have farmed properly and gotten your items, you are nearly immune to CC by this time. However, don't ever initiate teamfights. You can chase or CC, but even though you're a tank, your skills dictate that you focus on a squishie or chase with Q or R.
- Use R often, especially around creep waves. Grabbing as much health as possible allows you to push a lane or prolong a teamfight farther and longer.