I love Irelia, and I can't deny it. she is extremely versatile and brings an tanky assassin to the team which is extremely useful. I use this term as you can build her tanky and she will still burst down the enemy squishy in seconds.
I'm 1700+ elo in europe who got their by playing Irelia quite a bit. Here is my guide!
Irelia is a fairly simple character to play, but there are some simple nuisances to her that will help you do more then the avarage irelia. Let me show you the three different ways I build her. The first is for a very magic heacy comp. The second build is for a very balanced team where the damage comes from both physical and magical. The third build is for a very physical heavy team with a lot of tanky dps and physical carries. Each build is used for the required situation allowing for even more success in the game.

Bladesurge - Irelia dashes forward to strike her target. If it kills the target, Bladesurge's cooldown refreshes and refunds 35 Mana.
Irelia dashes forward to strike her target, dealing 20/50/80/110/140 (+) physical damage.

If it kills the target, Bladesurge's cooldown refreshes and refunds 35 Mana.
Cost
70/70/70/70/70 Mana
Range
650

A farm tool at the start of the game, and a gap closer for mid and end game. A very versatile ability that also allows you to get away from ganks.


Hiten Style - Irelia is skilled in the art of Hiten, passively giving her physical attacks health restoration. Activating Hiten Style gives her physical attacks true damage for a short period.
Passive: Physical attacks restore 10/14/18/22/26 health.

Active: Irelia's physical attacks deal 15/30/45/60/75 true damage for 6 seconds.
Cost
40/40/40/40/40 Mana
Range
20

I personally love this ability as 75 true damage is no laughing matter especially early and mid game. This ability also gives Irelia sustain in lane as well as the ability to duel with tanky characters and destroy squishies in a prolonged fight.


Equilibrium Strike - Irelia's attack balances the scales, dealing damage and slowing the target. However, if the target has a higher Health % than Irelia, then the blow stuns the target instead.
Irelia pierces her target, dealing 80/130/180/230/280 (+0.5) magic damage and slowing the target by 60% for 1/1.25/1.5/1.75/2 second(s).

If the target has a higher Health % than Irelia, she stuns the target for the duration instead.
Cost
50/55/60/65/70 Mana
Range
425

There is no other ability like this in the game, and you have to think before you use it. It does good damage and either slows or stuns the target depending on your health. Again a very versatile tool but one that needs to be used correctly. You don't just always press e on the target at the start of the fight and put it on cooldown. You save it for when they start running away or when you see that you are losing and need the stun to save your life or turn the tide.


Transcendent Blades - Irelia summons 4 spirit blades that she can fling to deal physical damage and siphon life from enemies they pass through.
Irelia summons 4 spirit blades that she can fling to deal 85/135/185 (+) (+0.5) physical damage to enemies they pass through. She heals for 20% of that damage against champions and 10% against minions.
Cost
100/100/100 Mana
Range
1200

A very underrated ultimate. It gives you sustain in lane as well as some really good damage if every blade hits. Don't worry about using this ability because the cooldown is relatively short. If there is a big wave of minions coming at you, get them all with your ult + q.


Ionian Fervor - Reduces the duration of stuns, slows, taunts, fears, snares, and roots for each nearby enemy champion.

1 Champion: 10%
2 Champions: 25%
3 Champions: 40%

A great passive which allows Irelia to stick to a target and kill them even if all the cc is aimed at her. It's great to be able to move .25 seconds after a stun which is suppose to last 1.5. Merc treads synergies really well with this passive as both of these stack possibly giving you 65% cc reduction.

my runes for irelia always stay the same:
9 x greater mark of desolation greater mark of desolation
standard runes for reds for any character that does mostly physical damage. you can also get attack damage runes for an extremely powerful early game, but you do screw with your late game power quite a bit.

9 x greater seal of resilience
Gives you an extra 13 armor at the start of the game making you quite tanky. you might also go armor per level because a lot of damage early game is magical. I like the early extra armor, especially since irelia only really works in a solo lane.

9 x greater glyph of warding
gives you 13 extra magic resist to protect you from the burst of mages at the early to mid game. Wouldn't actually go per level as that early magic resist is just so helpful.

3 x Greater Quintessence of Vigor greater quintessence of vigor
This allows you to duel champions in top lane. you hit them and they hit you. But then in the next engage you are back up to full life while they are still only half. you have just won your lane. Would not swap out these runes for anything but they do cost quite a bit.

you can go every mastery build imaginable for irelia and it will still work. My favorite is either 0/18/12 or 0/9/21.

the 0/18/12 gives you the extra armor, magic resist and health as well as damage protection from minions and enemy campions. the 12 in utility allows you to come back faster from death, gives you the extra experience, and allows you to keep double buff longer.

0/9/21 makes you less tanky but also gives it's own benefits like moving quicker, allowing flash to be on a much shorter cooldown, as well as just shortening cooldowns in general.

21/0/9 is for the players that want to fill more the assassin role. I like to balance it out a bit and not die after I've killed their squishy.

There are basically two ways you skill irelia.

1.

E > Q > W > W > W > R > W > E > W > Q > R > E > E > E > Q > R > Q > Q

2.

E > Q > E > W > E > R > E > Q > E > Q > R > Q > Q > Q > W > R > W > W

The first build is for sustain Irelia, and is a lot more useful in the current meta game with sustain champions being very popular. with the runes you are very very hard to push out of lane, but you need to get hits in to be able to do your damage.

2. the second is what I call the burst Irelia and I use this skill sequence for when I play against champions that arn't all that tanky or that cannot sustain themselves all that well. You are able to do a lot of front-loaded burst and then back-off.

Both sequences change your playstyle drastically and you have to choose which one in context to who your direct opponent is. from level 1-11 is generally how long the laning fase lasts, and which sequence you choose really helps you either win or loss the lane.

choose the first one if:

They have good sustain
are tanky-type champions
the burst won't really kill them or do enough damage

Choose the second one if:

they are squishy
there are a lot of squishy champions in other lanes
you don't need the sustain to win your lane (hard in current meta)

With irelia you can run 3 different types of summoner setups:
ignite/flash
exhaust/flash
teleport/flash

I generally use the first two for solo que or normal games as it allows you to win your lane easier.
ignite adds to your damage and is useful to make sure that you kill their carries quickly. It als prevents the enemy from healing. (soraka, warwick)

I run exhuast on Irelia when either my team dosn't have one or their squishies can kite you once you latch on initially and all your spells are on cooldown. (ezreal, ashe) It slows them down and reduces their damage as you catch up to them and your spells come off cooldown.

When I play with a full team I run teleport. Teleport is so useful in so many situations but if your team doesn't plant wards then it really loses a lot of it's effect. (when you take teleport you lose a point in good hands and put it in teleport mastery)

I don't run ghost on Irelia as I feel she is fast enough already and certain situations in league of legends just make flash the must use spell for almost every champion in the league.

Irelia is item-dependent!
She needs items to be strong. I generally use my first build in most games as it gives a very good balance. the second build is basically a direct counter to magic damage heavy comps. It's cost effective and you can't be bursted down while dealing good damage.
There are other ways to build Irelia like warmog's and atmas, but I found these to be the most effective.

starting items:
regrowth pendent + pot
good for a lane against a burst heavy enemy. It adds to your health regen allowing you to regain a lot of life before he/she is able to burst you down again. The regrowth pendent also builds into philo stone.

cloth armor + 5 x health pots
The cloth armor used to be able to build into the heart of gold. Now you can either sell it or build it into wriggles. Also the 5 health pots make you almost unmovable from the lane. Use it if your uncertain as to how to handle the lane and just want to survive it until 6.

Doran's shield
gives you extra life, armor, and health regen which are all useful for top lane.

doran's dagger
gives you extra life, damage, and miniscule life regen on hits. I like running this if I want to be extra aggressive in lane and know I can win it.

boots + 3 health pots
provides extra mobility when you need to dodge a lot.

boots:
Merc treads
combines really well with your passive to make you an unstoppable force and constantly apply pressure until either they are dead or you are.

Ninja tabi
a situational choice for when the enemy team has a lot of physical damage. You generally want mercs but if they don't have a lot of cc or magic damage, change it!

items:
philo stone + heart of gold




I didn't include a last item as you can base that on the enemy team. This can also be said for the items I suggested above. Irelia is probably the best champion at building to counter so analyze the enemy and get what is best for the situation.

You can jungle with irelia but then I would like to point you to a video of stonewall800: Play Video follow the suggested rune page from stonewall instead of the rune page stated above.

I personally don't like Irelia in the jungle as there are better options and she generally isn't able to get the farm she needs to be strong limiting the items you can get on her.

Alright well here it is. This is my first guide for moba fire and there are certain things that need to be added. I will continue to keep improving this guide through out this month until I am completely happy with this guide. I hope this is useful for you and please rate and comment!

july 23 - release of guide, added jungle section, added a test build for irelia (build 4), added an abilities section, deleted all the builds and simplified it, added color and icons (incomplete)