I've played Jayce many ranked games. I've been countered many times, but really it all relys on skill. I use this exact build every game. Jayce is a understated champion. Nobody really counters him if you play him correctly, because you can just knock everyone away. He is a very good champion to main ranked. My record is 7 wins 2 losses with Jayce. His possibilities are endless, along with endless fun. I hope you enjoy this build and character as much as i did.

As jayce make sure to use your gun mode E + Q to harass. Use this only on squishier based characters. This can be very mana heavy and won't do much damage to tanks. Use your hammer mode
Q + E to harass tankier champs, and even squishier ones too. It does % health so it's good on anyone. When they're at about half health, you can use your hammer mode Q + E to quickly initiate, cast your ignite off, switch to gun mode and chase them. This will usually result in you getting a kill and is a great way to get ahead in the lane. But the only way this is possible is if your constantly poking with Jayce's OP Combos!

Pros Cons
Good Damage Once combo is done, no other escapes
Offtank Damage output at early game isn't the best
Godlike poking
Ranged and Melee modes

Make sure to be last hitting. Try not to use your spells for farming as much, because Jayce is very mana hungry and you need this mana to harass and kill your opponent.

Jayce's combos have to be one of the best in the game. In gun mode your E + Q Combo can greatly damage low armor squishy champions. While tanky champions take alot of damage from your hammer mode Q + E knockaway combo. Do not engage until you are certain you can pick up the kill. I recommend trying to go for the kill when they're at half health or even lower.

Be sure to place down your gun mode E to give your team a speed boost, this can greatly increase your teams capabilities during a team fight. While in your hammer mode, try to knock them into your team instead of knocking them away with your E, your Q slows them and can give you this opportunity.

Make sure to harass alot with your Q + E hammer mode combo. Using this correctly, they can not trade damage with you, but instead they take massive damage and you don't. Play passively. Don't just try to harass all game, make sure to farm alot using your ranged capabilities to your advantage.

Jayce is understated overall. His capabilities can outplay any champion in the game if you play him correctly. Follow my directions and you will do just as good as i do. I hope you enjoy this build and champion as much as i do!