This build is based on speed both in terms of attack speed and movement. The build has moderate defensive capabilities and relies primarily on the life steal element to sustain the champion in combat. Note that I did not include:Mercury's treads
in this build, which combined with Irelia's passive makes it difficult to keep her crowd controlled. In a prolonged game you may wish to buy mercury treads, or if you feel your getting focused by CC.

A skilled player can pick the wrong page and still come out on top. That said runes are more useful early game then they are late game. Runes are by no means useless, try to avoid a rocky start and make things easier on yourself. Remember Proper Planing Prevents Poor Performance...


Flat Attack Speed Marks

• Hiten style only gets better the more often your attacks connect with your opponent.
  
• You only have a fixed amount of time to apply your true damage before it goes on cooldown armor penetration marks do not help maximize true damage. Lets be honest ignoring armor is better than halving or quartering it...
• Health regeneration for Hiten Style is a fixed number. IT IS NOT LIFE STEAL, more damage done to your opponent does not translate into more health gained for Irelia in terms of Hiten Style. The more you hit your opponent the more health Irelia receives.

Flat Armor Seals

• Armor early on is nice to have because it negates a good amount of damage.
• The higher the Number for armor the more points it takes to shave off a percentage of damage. For example if you have about 200 armor you are stopping about 60% damage give or take. Another 25 armor will increase that percentage to 69%. While I am not sure on the exact numbers I am sure that this pattern holds true.

Flat Cooldown Glyphs

• Cooldowns are more of an issue early on usually the more Irelia can use her abilities the better she will be, provided she has the mana.
• The quicker Hiten Style comes off of cooldown the more damage Irelia can do.

Move Speed Quintessences

• This one is obvious: To be an AD melee carry you have to first avoid being caught, second you must be able to catch the people you intend to drop.

Like I said in the summary no build is perfect for every situation. Always adapt to who you are facing.
Mercury's Treads

• The only reason I do not by Mercury's treads is because of personal preference and the attack speed I get from Berserker's Greaves (which I guess falls under personal preference) so if it works for you go for it...
• If you find you need magic resist early on, you may wish to buy them instead.

Thornmail

• Good item especially against Tryn or any other champion who deals a large amount of damage and has little to no defenses.
• as you may have guessed from the line above this item is not always necessary

Force of Nature

• This item offers extremely high magic resist
• Bonus move speed makes chasing easier and Irelia is fundamentally a carry
• Health regeneration is always a plus because you don't need to leave the lane to heal

Why not Banshee veil?

• Offers less magic resist than Force of Nature
• Mana is not usually a problem Extra HP is nice but the extra magic resist will translate into keeping the HP you already have.
• The spell block ability is nice but it is more geared toward champions who fire off all their abilities then fall back and wait for cooldowns. Irelia is more likely to stay in the fray until it is over or she is dead.

Ionic Spark

• Chain lightning makes this item good for farming
• Extra Health is always nice and attack speed... you already know why I like attack speed.

Warmog's Armor

• if you find that you don't need Thornmail or Force of Nature this is a good alternative especially when combined with force of nature.

Atma's Impaler

• This Item works well with Warmog's Armor
• This gives good offensive capabilities while still providing defensive.

Stark's Fervor

• Life steal, attack speed, and decreases enemy Armor what's not to like...
• Good alternative for Youmuu's Ghostblade

Heart of Gold
Personally I don't like to buy this item. Irelia is an assassin not a tank or a support character. Yeah, the item will pay for itself eventually but if you buy damage items and get kills (or assists) then there is no point in buying this item. As for the health, yeah health is good but why not buy a phage instead... And if your argument is that Irelia already does enough damage why buy more my answers is: you kill people faster, which means you can run away sooner or kill someone else before they get away... (the less time you spend killing someone the better...) If your getting zoned out of your lane and you want to buy a gold per ten second item or two get at least make one an Artifice Blade, it's at least part of the build...
Philosopher's Stone
Same argument as the one above... I almost never run out of mana with Irelia, unless I've fought three people in a relatively short amount of time and have to fight a fourth (and that's only with in the first eight levels or so and if your teammates haven't shown up to help by then, then you might as well surrender). Yeah, blade surge can be used more often to last hit, but auto attacks work just as well... watch your mana.

This build is designed to yield a relatively large amount of damage early on while relying on life steal / hiten style to keep Irelia alive, then building more defensive items later on. Be wary of being shut out of your lane because this can prove to be costly for you build however if this does happen it is not the end of the world, just play defensive until opportunity presents itself (usually in the form of a gank or sloppy dive on their part).

Even though I said you should max Hiten Style First, you will probably make more use of your Bladesurge ability. Bladesurge is a phenomenal farming tool allowing you to last hit minions for gold and for half the mana it would normally cost with no cooldown. Just Remember to keep an eye on the mana level because you can very easily run out even at half-cost so use it sparingly...

It is usually best to far till about level 4 or 5 then go for enemy champions. This rule of thumb is made to be broken though so keep an eye out for any opportunity you can exploit.

If you end up getting zoned out play smart. (This goes for every champion not just Irelia) Your enemy is getting enough gold already without killing champions. Being zoned out and unable to kill minions sucks but it is a lot easier to come back from it if you don't die during the lane phase. If you do get zoned out keep last hitting minions (ONLY if possible), do not push make the enemy come to you unless your team is there to assist you, and if they have you pushed up to your turret they are more likely to fall to either you or your team mates.

I have yet to try the Jungle since they reworked it. While this build is still viable you are probably better off getting a second opinion regarding a Jungle build.
Creeping with this class is possible, but it is not as easy as it would be with other champions. I recommend you stick to the lane. If you do decide to jungle, I recommend the following:

• Take Smite instead of ignite (obviously)
  
• Buy five potions instead of two
  
• Have someone help you get blue buff to start
  
• You may wish to build into the defense tree more.

Even if you do not ended up creeping you should be getting dragon for your team when you can. The Dragon can be safely soloed at 12 with a Wriggle's and possibly sooner if you know what your doing (that means be mindful of wards and have flash handy).

It is possible to Bladesurge over a wall if you have an enemy target that is close enough.

Wriggle's Lantern is a handy warding item but it can all be used to check a bush or the other side of a wall you would rather not get close to.

Sometimes using Equilibrium Strike immediately is a better option than waiting till later when your health is lower. If Irelia's health does fall low enough to require a stun the cooldown is usually finished from the initial strike.

Transcendent Blades works better if you position it so that your hitting the enemy champion and their minions.