Irelia

Middle

Perfection of Form

Aggressive trades, tank shredding, and all-in duels.

Precision

Improved attacks and sustained damage

Conqueror

After a few seconds in combat, your first attack against a champion grants bonus AD and convert some of your damage to True Damage.
Triumph

Takedowns restore health and grant bonus gold.
Legend: Alacrity

Takedowns on enemies grant permanent Attack Speed.
Coup De Grace

Deal 7% more damage to low health champions. Gain AD/AP after kills or assists.

Resolve

Durability and crowd control

Bone Plating

After taking damage from an enemy champion, the next 3 spells or attacks you receive deal less damage.
Overgrowth

Gain permanent health when enemy minions or monsters die near you.

Offense

+9% Attack Speed
Flex

+5 Armor or 6 MR (match-up)
Defense

+15-90 Health

WhyConqueror

Conqueror on Irelia allows you to use your massive mobility to take extended trades/fights and dish out massive amounts of true damage.

WhyTriumph

Triumph is an all-around solid rune choice. In 2v2s and 2v1s, the extra healing can be enough to grant you the ability to sustain and move on to the next target.

WhyLegend: Alacrity

The majority of Irelia's damage comes in the form of her Auto Attacks thanks to her [W]. Alacrity grants you the opportunity for an additional 1-2 autos when the enemy is stunned with [E].

If the enemy team has a ton of CC, Legend: Tenacity may be a better choice.

WhyCoup De Grace

Coup De Grace allows Irelia to continue chipping away at her target until their life bar is fully depleted.

If you're planning to duel to the death a lot, Last Stand can be a vital option to hold your ground.

WhyBone Plating

Bone Plating grants you early game damage mitigation helping you to sustain into an effective recall for Sheen.

WhyOvergrowth

Overgrowth's bonus HP makes you scale into a mid-game monster able to duel with anyone after your 2 item power-spike.