Whenever I see someone play Jayce, I quickly spectate the game and just compare how I play Jayce with how HE plays him. Most people go down the - path. But I, go in a somewhat ADC related path. (well, of course, item builds change because of enemy team composition, let me go over that later.)

Whenever I feel I am going to win a lane. I start with (well, this is usually the first items you should really get anyways.) and a couple of . Then, if I get good ganks and actually are dominating my lane, I just rush two and a . ( I can't wait for the next patch coming up, because I get to try out rushing using . I think it could be a good item, but I just don't see the appeal. Well, anyways, if you think you need the extra tankiness, you could just skip and buy . If you already got your , leave it, and try to rush an . ( well, if you think you can use the burst and the slow of , you can certainly just rush that from Phage.

Don't forget this against:
AP:
AD: which you can also sell like Hexdrinker if you think you need the extra slot for a more reliable source of damage or armor.



Remember:
If you're going against a Cho'gath or a Rumble, or any AP scaling solo top champions, Always buy a , unless you feel confident enough, which is highly doubtful if you're in a ranked game. Because cockiness can lead to YOU feeling like rambo and throwing.


After one/both of your offensive core items: (/)
You should really go for a defensive item.
What I do, is either buy dmg/health items, preferably, or a . ( Your W can sync with sunfire capes' dmg and that extra armor/health can go a long way.)

Or I can go and upgrade into a to shutdown their carry. Or an alternate item but slightly similar effect and purpose. ().

After these core defensive & offensive items. Feel free to buy items necessary for shutting down the enemy team. Usually if they go AP, I can just throw a at their faces.
Or IF.... please, IF you are DOMINATING the game. If you didn't get both of the Offensive Core Items, go get BOTH. Slow and Burst from your W in cannon mode with the help of and the will totally kill anyone on your path.


These are the sample builds I made if you guys are already locked in as Jayce.

Snowballing/Balling/DOMINATING your lane item build.



Against AP-heavy teams:
or


Against AD-heavy teams:
(yes, a wriggles lantern, if you are getting poked hard and need that extra ward and armor, don't forget the dmg and Lifesteal too, this item, can save your butt.) or or or and Any choice of an offensive item such as or any item you feel like that's going to help you, or more importantly the team in massive teamfights.