Hello, this is my build for Jarvan IV. THE PRINCE! My build is a tanky build that still deals some nice damage. Although you won't be decimating people like a brutal assassin (It's not what you were made for anyway), you will put out some pain if you hit all enemies with your passive and your shield (W) + randuin will be provide a nice bit of CC for your team.

Pros

- Great Damage even if built tanky.
- 3 forms of CC without items (5 with)
- Can survive a lot if not built tanky.
- Q/E nice escape / get to battle mechanism.
- Ultimate is a very good form of trap. (DAMN YOU FLASH!)
- Ultimate goes very nice with Malzahar. (Null Zone ftw.)

Cons

- If you miss your Q+E combo on trying to escape most likely death.
- Sometimes hard to decide when to use his ultimate.
- Ultimate can trap teammates if you don't Press R to release it
- If CC'd - Can't get to everyone with passive = Dmg decreased significantly.

10/19/1
Attack Speed in both Defensive and Offensive to get that passive off quicker.
Improved Ghost And Exhaust - self-explanatory.
Otherwise a pretty standard Tank/DPS hybrid mastery.

Ghost and Exhaust - Both Improved.
Ghost is very useful for escaping and chasing, almost always it's my first summoner spell. (Without it I feel like I'm missing a part of my heart (Exaggeration) ).
And Exhaust is very good for Melee carries like Yi, Trynda etc. and it also helps you make sure people don't escape from your ulti alive.

Alternatives -
Flash
If you miscalculate your chances of survival inside your ultimate.
Clarity
Jarvan is quite mana hungry if you harass a lot and without masteries that benefit mana regen, although I don't have this problem a lot so low priority.
Fortify
Can be useful but sometimes really not needed.
Revive
Well, if you want this spell go for Preservation.
Heal
I usually don't run it but can prove useful in some situations.
Clarivoyance
Support Spell but it is useful to use it if no one has it on your team and you don't really want to spend money on wards (CHEAP!)
Smite
Jungling, I might write a seperate guide about Jarvan jungle.
Rally
Goes well with your flag but meh. I wouldn't really consider it top priority.
Teleport
Ward Ganks and Lane Help - Take instead of Ghost if you must.
Ignite
Good bit of follow-up damage and good against Vlads and those pesky MUNDO!'s. Replaces Exhaust.
Cleanse
Against a heavy CC team - Yes please. (Take instead of Ghost)

The build listed above is what you want to get for mixed teams. With mainly phyiscal damage but there are alternatives.

Atma's Impaler can be changed for Randuin's Omen in the item order if you are doing well.

The Impaling Prince (Damage)

Any BF Sword Item - A load of damage
Bloodthirster - Great Item if you want to dish out a lot of damage and survive.
Infinity Edge - Crits are good. And also that awesomely sexy 75 damage.
Black Cleaver - Dragon Strike + This beauty = Win.
Sword of The Occult - Damage
Leviathan - Helps with Atma's
Mejai's? - No. Unless you want your flag to hurt which is just pointless.
Sword and Leviathan - The Prince is very good at keeping stacks in my opinion.
Don't really have other suggestions for damage apart from Last Whisper for some armor pen.
Warmog - Same as Leviathan

The Invincible Prince (Defensive)

Force of Nature for Yomuu's Ghostblade if you feel you need more Magic Resist and don't need damage or the active.
Frozen Mallet - Any defensive item you wish.
Atma's Impaler - Only for defensive items.
Randuin's Omen - Always has to be there imo but if you are completely getting slaughtered by mages - Quicksilver Sash on CC and Force of Nature if they have no CC
Quicksilver Sash - Great item overall for a cheap price. Replace a phyiscal defensive item.
Sunfire Cape - Go in there and do some burning - Can replace Yomuu's or Frozen Mallet
Guardian Angel - If you really want to inititate but don't think you can survive the initial burst. Very good for melee teams. And mixed as well.
Aegis of the Legion - Possible replacement for Yomuu's - Good stats overall. Very nice to have and compliments your flag.

Use Elixirs of Fortitutde and Agiltiy! With an Elixir of Fortitutde your Atma's Impaler will give you around the 75 damage mark which would put you at around 230 damage overall and with the AS and Crit from Agility Elixir you will be doing a fair bit of impaling.

A flavour build. Don't take much attention to it. It's a build I would go for if I was a DPS ignore it in voting/commenting.

All the runes listed above go well together. Although there are loads of alternatives.
Instead of Dodge you can get anything you like. Dodge is crucial if you are going to go full defensive though.
Armor Pen - Not really reccomending to change but I guess Attack Speed is okay.
Health Quints - Armor Pen Quints or Dodge/MR quints. Depends on the situation.
CDR glyphs - You can switch these to more defensive but CDR is very good on Jarvan in my opinion.

This is a work in progress. The video will be released soon when I can get a custom game sorted out showing you all the places in which it will be really helpful to escape a gank or join a gank mid-gank. (Gank on gank with a gank sandwich!)

The skill sequence I feel maxing out Dragon Strike first allows for awesome harass capabilities and also damage. While if you feel you need more survival max out the other two before dragon strike.

I hope you didn't get too bored from reading this guide I will update it when I get around to it.
Would like some feedback with votes if possible.
(Also you want to play the Battlefield Theme when playing him. It really helps) Play Video