Jayce

can fullfil almolst any role in the team, depending on the build he can be jungler , Ad carry or solo top.
First part of my guide is dedicated to solotop Jayce, second to AD carry Jayce and in the end jungler Jayce. Each of them requires different playstyle and build.

Basic info about Jayce.

Pros:
-versatile like noone
-can pull off amazing combos
-huge nuke
-tanky (hammer form)


Cons
-mana hungry like no other fighter/carry
-squishy (cannon form)
-short range as carry

WORD ABOUT COOLDOWNS!

I must admit im currently researching his cooldowns in different forms. Im certain they are not 100% shared but not 100% independant. So if anyone will get this faster than me feel free to comment :)

WORD ABOUT SWICHING FORMS! Mercury Cannon / Mercury Hammer

Swiching forms is free with 6 second cooldown. Simply swiching your form gives you bonus for your next autoatack. BUT 6 second is piece of time and having 4 seconds to knockback during enemy ganks...fail:) so mostly i advice to sticking to one form during passive laning and start swiching when you start to harass.

WORD ABOUT JAYCE AND MANA Mana Potion

Jayce is mana hungry. Very mana hungry. One combo can empty you whole mana pool. Always try to carry 2-3 or mana pots with you. Gonna need it even more than red counterparts. Hammerjayce reduces this problem with Lightning Field, and Junglejayce negates it completly with blue and Lightning Field but still problem persist.

I had lot of thinking in this build about items cause every single item had to contribute to Jayces AD somehow here, while maintainig tankyness required to fullfil solo top role. Why so much AD? Every single one ability of Jayce is AD based (save Lightning Field but i found it kinda weak). As team offtank Jayce most of the time gonna spend in hammer form as it gives really fair about of armor and magic resist (35 on lvl 16).

First hammer abilities:

To The Skies! / Shock Blast

its Jayces gap closer and slow in one piece. Nice range/medium damage.

Lightning Field / Hyper Charge

its cannon counterpiece is pretty nice but as Hammerjayce it sux, just low dmg AOE scaled of AP that we are gonna have zero. Take one point to boost DMG during ganks/early teamfights and max last. Only utility is mana regeneration with every hammer strike, nice but not essential.

Thundering Blow / Acceleration Gate

main Hammerjayce skill, high damage and two forms of CC in one skill: knockback and stun after, great harrasment skill and great to pick out those nasty carry in teamfight.

Ok now to the actual laning:

You got two options:
-lane as cannon and constantly harras with autoattacks and cannon Q+E combo (explained in carry section). High risk but can be high reward tactics as his cannon has relative low range, you'r squisher in this form, and you have no CC. But still they are certain champions that can't handle this (Trynda) or you can't or gonna have hard time as melee (Kennen, Teemo). This is kinda "feel" thing.
-lane as traditional melee tank, just usual tank'n'spank on top lane, you got really nice harrasment with To the skies!+ Thundering blow as you close gap with Q and then deal heavy dmg and knock enemy back with E, so your enemy looses his chance to retaliate to you.
Perfect harrasment combo is: (start in cannon form) start with acceleration gate then put shock blast in the face, switch to hammer, the close gap with movement speed from switch and to the skies, activate lighntning field and try to knock them back with thundering blow.
Enemy should be running like chased by whole hell now with less than 25% life.

During team fight you should initiate and try to jump to carry and kick him back to your team. Try to use To the skies! slow to position yourselves behind the carry to kick him back.
Unless low on mana always try to turn lightning field for additional damage.

Word about items:
All items contribute to your AD by beeing filtered by Atma's Impaler. Everything in this build gives you HP and in consequence AD. Your armor needs are satisfied by Lantern and Atma while MR are satisfied with Boots and Banshee. Booth boosted with hammer stance. I found this really tanky while still having decent AD to make your skills hurt.

This gonna be short part:)
Pretty much play standart ad carry...but hey! Hes got so short range why play him? Because he has got immense harrasment with Shock Blast shot though Acceleration gate (and i mean-really high damage, on low lvls you can easily take half hp with one shot of this baby)+plus you got a gank-panic-button called the hammer.

First cannon abilities:

To The Skies! / Shock Blast

its your main damage dealer and harras skill. You are gonna use to win your lane, to start a teamfight and to finish up the runners.

Lightning Field / Hyper Charge

Jayce main steroid in cannon form, it basically raises your AS to the 2,5 cap for 3 attacks and boost damage on higher levels of the skill.

Thundering Blow / Acceleration Gate

as Cannonjayce you only need one point in this to boost your shock blast. Just one point cause damage amplification to blast stays on 40% on all levels.

Jayce is very strong early game and you got to take advantage of this as later in the game you are going to loose this advantage so you need to get a kill pre 6 to be on optimal track. Tactics as AD carry Jayce should be to harras with Q+E combo to get enemy low and then switch to hammer and finish the enemy with another Q+E combo in hammer form this time.

Also switch to hammer when enemy gank is coming or already on the move it gives you 3 things:
-movement speed boost
-armor/magic resist boost
-crowd control
Trinity that you need to avoid gank:)

In team fight you need to stay back until tank initiate then pop your Q+E combo right into the fray then pop you W speed boost and keep DPSing. When you start beeing focused switch to hammer, slow then knock enemies back and try to retreat.

W.I.P but definitly gonna be there cause hes got so much jungle potential that im gonna try it.
And yea that is 3rd way;)

First why no Sheen and no Trinity Force? They are both in recomended and i see Jayce spams skills like madman?

Yea but:
Jayce is 100% AD, every single item contributes to AD in both builds. TF gives small amount of AD for price of 4000g. Just no. For 4k can get much more AD here.
Of course you get also:
HP - in carry you dont need this as much, in tanky you already got plenty.
AP - hee..? He has got just one weak skill scaling on AP. Just no.
Bonus dmg after skill - ok that is tempting but Jayce is more like QWWEQEEEQ in less then 3 seconds. TF got 3 sec cooldown so you gonna get just one passive that not gonna raise your damage output so much, not like Hecarim's constant Q spam or Ezreal's/Corki's ranged spams.

For me TF is just a waste on Jayce cause he is one way oriented => AD , Trinity Force is too much...trinity:D You may try it on Hammerjayce but I stronly oppose it.

Second maybe more Armor/MR as Hammerjayce or Cannonjayce?

-On Cannonjayce nononono. You a carry right? You'r supposed to be squishy here, hammer is only an useful emergency here not something you should weive into your build.
-On Hammerjayce you would be going full tank this way, and i don't think this is Hammerjayce way to be. He's more valuable as offtank with roughly 150 armor and 120 magic resist. With warmog ist gonna be enough.

If he is so AD oriented why no full AD runepage?

Try it. Sure you are gonna hit like freight train but at the expense of early squishyness on Hammerjayce and overall game squishynees as Cannonjayce.

SO PEOPLE...HAMMERTIME!