Introductionary disclaimer:

I do not wish to claim that my current calculations and/or estimates are one hundred precent correct. The guide will endure chances as the champion gets tweaked (which it indefinately will, seeing that he is brand new to the League of Legends).
Secondly, I do not wish to claim that the way I personally set up my champion is the only way to go as I am well aware that he can work quite well as an offtank/support, not just a bursty carrier.


Jarvan IV, The Exemplar of Demacia:
Though beaten in a past-time spar versus Jericho Swain, the master tactician, and his Noxian battalion, Jarvan is not one to look down upon. Wielding a humongous lance, sharpened to the extreme, and engraved with Demacian runes, his strikes inhabit such force that it cleaves most any opponent in half in the blink of an eye.
Even Xin Zhao, a fellow solider wielding a lance, silently fears this incredibly strong warrior's piercing stare; even though they are on the same side.
Fighting for his father's land, honor and riches as the prince of the Demacian, no one shall be left to challenge either him, or his future empire.

Jarvan IV, The Exemplar of Demacia is a rather heavily armored melee bruiser/support champion which has recently been introduced to the League of Legend's (seemingly) endless archive of heroes from all over Runeterra.

Jarvan takes slight resemblance to heroes such as Xin Zhao and Shen, in that he has the ability to quickly move in to attack, he has the ability to further boost his allies armor and attack speed, he has the ability to lock down and/or chase, and he has the ability to leap small-to-medium sized walls around the battlefield (and so on and so forth).

"Pros":
- Many, many ways to use his abilities. Creativity takes the win here.
- Great burst damage.
- Great chasing capabilities.
- Good escape capabilities.
- Pushes and farms minions well.
- Boosts friends.
- Great fun to play.

"Cons":
- Quite slow without boots and/or EQ-spamming (more on that later).
- Relies quite heavily on his mana pool. No mana; no juice.
- Highly prioritized in team fights and for ganks.

Passive - Martial Cadence.
Q - Dragon Strike.
W - Golden Aegis.
E - Demacian Standard.
R - Cataclysm.

Martial Candence is an hilarious powerful passive buff that which allows Jarvan to hit enemies (champions, creeps and neutral mobs alike) for up to an aditional 400 damage.
The way the skill works is that when Jarvan swings, the system calculates out ten precent (10%) of the enemy targets health, and it allows Martial Candence to deal damage equal to that ammount. However, the skill will never excede 400 damage.
This means, squichy little Annie at 1700 health (un-modified at level 18), will lose an additional 170 health on the first strike Jarvan hits her with, along with his powerful auto-hit damage. She will then recieve a debuff (or rather a buff) that prevents her from being affected by the Martial Candence for six seconds.
HOWEVER, this does not mean you can not switch to a new target, strike them for (often) far over twenty precent of their health, before moving on to yet another target.
I have found this to be incredibly useful when fighting more than one target (seeing how 10% of anyone's health is to be considered as quite a bit).

Dragon Strike is Jarvan's main ability, and for a good reason.
What the skill makes Jarvan do is swing his lance in a direction of your choise, dealing heavy damage to enemies in it's path, and lowering their armor.
The great thing about the skill is that the mana cost is really low, making it a reliable harrasing skill.
The secondary part to this skill, besides the amazing damage and reliability that follows by it, is the Shen-like teleport that which can be obtained by aiming it towards your battle standard

(E - Demacian Standard)

Combining E and Q to get out of crowd controls, slows, snares, traps, ganks and so forth will up your game tenfolds.

Golden Aegis is probably one of Jarvan's least useful abilities.
What the spell does is that it shields Jarvan from a rather limited ammount of damage. However, this is not the only thing the shield does. It also sends out an instant wave of bright light that which slows enemies that it passes through for two seconds. The slow makes the skill go from "meh" to "woop" as it adds another good gameplay mechanic.
The shield can be used for pure harrasment, as a "holy****Iamabouttodie"-survivability-skill or a "you are not getting away from me that easily"-chasing-skill.
Oh, and if you have more than 75 mana, and the shield is off cooldown, it will automatically activate if you drop below 300 health, which is incredibly useful if you suddenly find yourself as the opposing team's prime hate/gank target.
(And, don not get me wrong, the shield and the slow are both incredibly useful, but I chose to prioritize on the damage output of this champion, and not his survivability.)

Demacian Standard both grants Jarvan a selfish, passive buff, and it can be used to support nearby champions; granting them both attack speed and a slight armor boost. Placing out the standard does NOT remove the passive buff from Jarvan's stats. In other words, when you place it, you get the buff twice.
The buff is all well and good, jolly yay for more attack speed and some extra armor, but what you will be using it for is to grapple across the battlefield to your enemies, over walls, out of sticky/painful stuff, and so on and so forth by casting your Dragon Strike ability in the same direction as your standard has been placed.
As you fly across the battlefield you will knock champions and creeps up into the air in the path you are moving, making it an excellent initiator for team fights (however, you are likely to die if you do not get instant support in five versus five fights. That is, if you leap towards your five enemies all by yourself, stun them for a second, but end up fighting them alone because your friends are busy filing their toenails or such).
Oh, yeah, and as you place the standard, it adds a tiny aoe-damage to the enemies that are right by where it lands.
Placing the standard is instant, so you can position it and grapple away more or less instantly.

Grapple: grappling hook, claw shot, hook shot and so forth. Zelda, guys. Link has it in most of his games.

Cataclysm is alos a quite fun ability, as what it does is heavily damage a champion of your choise, then wall them in for you two to have a death match of your own. The walls last for three and a half (3.5) seconds, which is more than enough for Jarvan to take down most any targets.
The walls are to be considered small at best, so there are a few heroes that can chose to leap over/teleport through them, but the most important part of this spell is the immense damage it deals.
You may chose to collapse the walls by hitting R one more time after the initial damage has been delivered to the target.

As for the skill sequence I go for:

Q, E, Q, W, Q, R, Q, E, Q, E, R, E, E, W, W, R, W, W.
The reasoning behind this is to maximize personal damage first, then the support that which I may grant others through the battle standard, and lastly the shield.
Damage first, survivability second.

Level one through five.

Play style: agressive, yet not stupidly daring.
You start out by spamming your Dragon Strike on the enemy hero at your lane that which has the lowest health pool. If you manage to line up a two-hitter, do so (as in you manage to hit both heroes on the lane).

Level six through eleven.

Play style: balanced, yet not a coward.
By now you should have gotten the boots of your choice, and preferably a weapon. These will improve your experience with Jarvan by the thousands.
Now you will be able to deal heavy burst damage with an EQR-D-W-combo, as well as survive most ganks with a WEQ-DF-combo.

Level twelve through eighteen.

Play style: role focused, but ready to take over for the others on the team.
If your game continues to the endgame phase you will be able to burst down most any enemy as a damage dealer, survive pretty much any attack as an offtank and you will be of great help to your friends in the pending teamfights around the middle lane (usually ends up on the middle lane, anyway).

Masteries:

21/0/9 is what I am currently trying to run as.
This is quite simply because it is a perfectly selfish and "I DEAL DAMAGE ROAWR"-like spec.
There are of course other choises such as 0/20/10 for a very durable offtank/jungle version of Jarvan, but I (as stated above) am focusing on the damage aspect of the champion as of now.

Runes:

I would like to explain why I have put up both attack speed and armor penetration as viable alternatives to this build.

First off, the attack speed.
Considering how incredibly strong Jarvan's passive ability is, removing 10% of the enemies health in a singly blow, it should be quite easy to see why I have put my points into attack speed. Say you are fighting enemies A through E. Let us say your attack rate is at 1 attacks per second, which would give you enough time to strike up to 6 targets before target A loses the immunity to the damage from Martial Cadence. You start out by rotating attacks from target A, to B, to C, to D, to E, giving you 1 second to move back to target A to start the routine over.
This might seem a bit excessive, but every bit counts; and especially when it comes to this specific passive.

If you are slightly less into the complete geeky-micro-min/max-elitistical ********, you might go for either armor penetration or critical strike chance, as it would require a lot less of you, and the result does not vary too much from the ones with the attack speed runes.

In other words; both work, do as you please.

The reasoning behind placing out magic resistance gyphs is that Jarvan comes with a rather large health pool, and with a bit of armor; but with a severely lacking magical defense.
Placing out a few Shield-glyphs should keep you alive a bit longer while Karthus tries to zap you to death, or Nunu attempts to punt you to the floor with a hail-storm of snowballs.

Great.

- Ghost.
- Exhaust.
- Ignite.

Fair.

- Teleport.
- Flash.
- Cleanse.

Wasted keybinds.

- Smite.
- Rally.
- Clairvoyance.
- Clarity.
- Fortify.
- Heal.
- Revive.
- Promote.

The reason I have placed items as far down as this is because you should consider reading over his skills and stats a few times before making selections.

Now, to the point;
Attack speed, critical strike rating and some movement speed = gold.
The three stats that are mentioned right above are the ones I look for when I pick out items for my burst damage setup.

Weapon of choice - boots of choice - a defensive item and/or three/four more weapons.

The itemization is quite different due to the variety of enemies you may encounter in the game. Usually, if you face high ammounts of crowd control, you might want to chose to grab the Mercury's Treads, and not the Berserker's Greaves; or Randuin's Omen, and not the Last Whisper.

I feel that saying "ITEM A IS BETTER THAN ITEM B" is incredibly silly, as mentioned above, everything boils down to two points;
What does your team have, and what does the opposing team have.

However,

seeing how everyone expects a guide and not guidelines I will say this much:
I usually start out by grabbing the Brawler's Gloves and one of each potion. This is, quite obviously, because it is a part of the Youmuu's Ghostblade, which will allow you to land many a kill later in the game.
Why, might you ask, do I dare to go straight for the blade, and not for something defensive, such as boots? This is because the damage output Jarvan posesses, and the great harassment he can throw out towards his enemies usually keeps them busy while you stay out of range from their spells, leaving you at one hundred precent health, and them at under seventy.
From here I move on to boots, which most of the time would be the Berserker's Greaves.
More attack speed and movement speed!
The following part is where I either pick up my Phantom Dancer or my Randuin's Omen, depending on the enemy team's setup. After said item has been chosen, I always go for the Last Whisper, followed by Infinity Edge.
Lastly, if you are so lucky (or unlucky, if you disapprove of long fights) that you manage to gather the 15600 gold that is required for this item-build, you pick up Bloodthirster, and you will never again fall under the ninety precent health-mark.

Primary item-sequence can be found at the top of the guide.

Secondary dps item build:
Berserker's Greaves - Last Whisper - Infinity Edge - Phantom Dancer - Black Cleaver - Frozen Mallet.
This setup will allow your skills to deal quite a bit more damage, rather than having you toss out a large amount of autohits, which again means your burst will be quite a lot higher.
The downside with this is that your damage while not spamming skills will be quite a bit lower than if you go for the attack speed build.

Personally favored tank setup:
Mercury's Treads - Randuin's Omen - Warmog's Armor - Frozen Heart - Banshee's Veil - Guardian Angel.
The reasoning behind this item build is that all the items mentioned above scales well off of eachother, especially with magic resistance glyphs and/or seals (I would also go for flat health quints/marks, as they would equal out the health-to-armor-and-resistance).

Jarvan is a champion with a lot of potential.
He can push, he can farm. He can tank, he can support. He can block and he can harras.
In other words he is a very versitile champion, and should be welcomed in to the League with open arms.
This champion scales greatly with gaming skills and the ability to analyze the fight that is unfolding infront of you.

I am personally retiring from jungling as Udyr, to do some hardcore laning as Jarvan.
I hope to see you out on the battlefield.

Until then;
FOR DEMACIA!

* First posted March 5th at 16:26, CET.
* Spell- and grammar check, March 5th at 20:35, CET.
* Added more details to the guide, March 5th at 23:00, CET.
* Reposted due to a large amount of unjustified downrates.
* Additional item builds added, March 8th at 10:20, CET.