Hello, this is my first build on Mobafire, so what better champion than one who does not yet have an existing build? Anyway, as you can see, I build Jayce like an AD carry. He's actually terrifically strong, especially with a good support who has a lot of crowd control. I think my favorite support to lane with on Jayce is Blitzcrank, because he can pull them back into your stun, then knock him up while you beat them to death, and if they get away, you can just switch to Cannon form and finish them off with a quick blast from your Mercury Cannon's shock blast.

While flat AD or Attack Speed runes can be very good on Jayce, he does need a good amount of defense to be effective. Being new, he is often focused in teamfights as not many people have seen him played to his full potential.

The masteries and items are just typical AD carry masteries.

Basically, you want to max your Q first as it does a TON of damage, and your W really comes in handy. Your stun doesn't do that much damage, and the extra runspeed really isn't necessary in most cases.