I felt a certain obligation to the community to make a guide for Jarvan at this point. My biggest complaint with the current community is I have seen a TON of Jarvans building dps. I realize the current metagame supports BAM BAM DPS TANKY, and characters such as Irelia have been in the headlines, but to me, Jarvan screams tank tank tank. Don't get me wrong, I am not saying that Jarvan is the best tank in game, I'm not saying he can pull the role better than an Amumu or Rammus, but I believe if played correctly Jarvan can create conflict in the enemy team. If they target you, your whole team will crush them. If they don't, your dps EVEN WITHOUT DPS ITEMS will crush them. So here goes nothing, enjoy the guide.

Pros:

Great early game
Good CC if used well
Beastly mobility with his flag and lunge
Good Ganking
Great ability to stay in lane
Decent at farming later
GREAT HARASS EARLY

Cons:

Mid lane is best, to get an early jump
People will call you an OP noob
Without a team of solid dps you can get stuck (Even with subpar dps you will be fine)

First off are runes, many people will wonder why I would grab these runes if this is in fact a tank build. The fact of the matter is, early game will be VERY important for this build. With the extra armor pen you will do more damage. The extra mp regen even by level 2 (and even level 1) will allow you to harass with your Q (see later in guide). The cd reduction will help greatly early game with some extra harass and late game where your shield is BEASTLY. And lastly the flat health Quints give a little more staying power.

Again, this guide is a GUIDE not a forced path, if you prefer dodge runes or mres, go right ahead, many of these are viable, most depend on the runes available to you.

With Jarvan I'm currently rocking out with a 21/9/0 mastery set up. This runs true with a more offensive based tanky character.

OH WAIT I THOUGHT THIS WAS A TANK BUILD!!!!

Exactly, you can build 0/21/9 if you like, or 9/21/0, but I prefer the 21/9/0 for a few reasons. By end game fully built you will be tanking like a madman with this build, your shield will help with a TON of damage later, but my issue is early game. I find that early off I can take a little more offense to dominate my lane. I feel that the cooldown reduction is VITAL to Jarvan in a lot of situations, and (this is not confirmed) but I believe his passive needs mpen? His passive is magical damage so in the case of this having effect, I would advise at least 9 points in offense.

Again, these masteries are not set in stone, but the basic principles stay the same.

First off, I am sick of people seeing these builds and thinking OMG I HAVE TO BUILD THESE EXACT ITEMS. For this reason I attach this to the beginning of this section, this build works well for a team that is pretty much balanced in terms of physical and magical damage champions. If there is a character doing really well in your game, rush the corresponding item to counter it.

Early Game:

Take mid lane. I don't care, deal with the trolls, until Jarvan gets nerfed, which he probably will, Jarvan is basically the new old pantheon. Anyone who doesn't understand what I mean, just go mid. Grab your Doran's shield and you are set, start last hitting minions and harassing the other champion with your Q, even at level 1 the damage is great. Keep harassing till you hit level 2. At level you grab the standard (your E move) and begin harassing with both, if they are keeping you at bay, feel free to hit them with the flag, the damage is surprisingly decent. Any chance you get, you should drop the flag behind them, Q into them, autoattack once to proc your passive, and then fall back. By level 2 or 3 they should be getting low, if they are still in lane all you need is a flag behind them, then a lunge in, with one auto attack you can drop them from 300 hp or so, use ignite and flash in(/out) if necessary. If you are low, return and spend your gold, you should have enough for Heart of gold soon. Pick it up for the extra gold all game and head back to lane. If you haven't killed them, at level 6 you can lay down 600 damage EASY with his ult, flag, Q and then ignite. You should get first blood. Continue in lane, harassing as usual till mid game.

Mid Game:

At this point you should have 2 or 3 kills, and the mid lane will probably be complaining about how OP you are. After your Heart of Gold great Merc treads, the decrease in CC effects is VITAL. At this point there may be team fights breaking out. The most important thing to realize about Jarvan is how your passive works. In a team fight, you should NOT ever attack an enemy multiple times in a row unless they are the only person or if they are almost dead. Your passive should be used once on each enemy rotating throughout the team. With 5 enemies, you can attack 1 each second, and drop 10% of each of their health. Be sure to be careful when using his ult to put your team in a good position vs a dangerous one (more to come). Grab your giants belt as soon as you can, Warmogs next is important because the longer you are alive, the more damage your character will do with his passive. REMEMBER, the flag gives your team bonuses, ALWAYS drop it during a team fight and when pushing a turret, it helps a ton. When pushing a turret solo, put the flag behind you, so that if a gank comes you can lunge away easily. In team fights, put your flag on the far side and be sure to disable as much of their team as you can.

Late Game:

As more team fights break out, be sure to be in the middle, use your shield EVERY time it is off cd, and be sure to help your team with the flag. Many people will try to focus you because of your high damage, fine, let your team reap the rewards. By the time you get into your FoN and Thornmail nobody will be able to touch you. Add in Randuins, and REMEMBER THE ACTIVE, and teams will get shut down. Remember, you are a tank, and your role is to attack each enemy once and then rotate, if you do this wrong, you will fail, don't be afraid to hit a tank ONCE to proc his passive. And remember, the more enemies there are, the more your shield will do, with Guardian angel ending your build, you will be an all around pain in the ***. Enjoy

Again, this section seems strange but is self explanatory, I use his Q and E maxxed early because honestly he is OP and can net some early kills. The damage is awesome, and with a few early kills and warmogs your shield will do that much more.

I choose flash and ignite again for huge benefits early game with Jarvans rediculous harass, ignite is perfect for first blood. Also, it helps a ton late game to drop on a lifesteal champ etc. On the note of flash it is great for that extra burst of initiating, and can also be used along with his ult, if you need to escape or isolate a melee character, ult them, and then flash out. YES, you can also flag/dash out, but this way you are out faster, and can use his lunge to disable the enemy team.

Other good choices:

Basically any other tank summoner spell, ghost, exhaust etc.

More to come, but try out the build, please comment before a downvote, I'm open to suggestions, try it before you knock it. And I don't want any DPS IS BETTER posts... Good luck, I will update the guide and add more specific situations as I go.

By the end of this build though, you will literally feel Immortal