You love Jax that's why you are here. I am skipping his story and all the **** which doesn't help his game play.

YOU SHOULD KNOW HOW TO SMART CAST SPELLS.

Only few things u have to know about Jax.

1. 1 AD = 3 HP
2. 1 AP = 2 HP
3. 100 HP = 2 AD Atma's Impaler so 3000 HP = 60 AD

Jax is not OP champ from the start. He shines at late game, where he can stand on his feet and fight. You want your fights to be long so that, you can go your full potential.

I love to Tower dive that's why Garrison and Ignite at lvl 18 = 410 extra damage.

It is seldom the case where a champion is defined by his actions after joining the League of Legends rather than before. Such is the case with Jax, for whom the argument could be made that he is the most prolific tournament fighter currently at the Institute of War. Before joining the League, Jax was an unremarkable soldier-for-hire. For reasons known only to the former leader of the League, High Councilor Reginald Ashram, Jax was put on the top of the list of candidates to receive a League Judgment - the interview process that either accepts or rejects a prospective champion. His Judgment was the quickest in League history, where the Doors of Acceptance glowed and slowly swung open as soon as it began. Jax faced no recorded Observation or Reflection during his Judgment.

Jax proved himself to be an immediate terror in the Fields of Justice. The self-proclaimed Armsmaster of the League rattled off a streak of consecutive wins that to this day has not been matched. A number of summoners in the League grew concerned that the perceived objectivity of the League of Legends would be questioned by the presence of an unknown fighter who was unbeatable. For this reason, the new leader of the League (following Reginald Ashram's disappearance), High Councilor Heyward Relivash, created special restrictions for Jax to fight under. This was something the League had never done before, and something which has never been done since. The burly fighter responded by imposing his own special conditions; as a means of protest, he permitted himself to fight using only a brass lamppost. Neither the League's sanctions nor his own has affected his winning ways. The League has since rescinded its sanctions, but Jax has not; he fights and fights well with his trusty brass lamppost.

"Be advised - there has been an outbreak of lamppost-shaped bruises in the League of Legends."
GragasSquare.png Gragas

Mobafire didnt updated Masteries for Dominion.

Jax needs fights to be long to win those fights thats why 9/21/0 mastery.
That Fortify mastery also good for Dominion.

Runes
Greater Mark of Scaling Attack Damage x 9
Greater Seal of Evasion x 9
Greater Glyph of Scaling Ability Power x 9
Greater Quintessence of Scaling Attack Damage x 3

AD at lvl 18 = 35 x 3 = 105 HP
AP at lvl 18 = 28 = 56 HP
dodge = 6.8%
Free HP = 161

Every game u hit lvl 17-18 easily so, its better to get those runes, dont forget to multiply those numbers with x hp u will get =]

Core Build = Hextech Gunblade + Abyssal Mask + Atma's Impaler

+ choice of boots Ninja Tabi or Mercury's Treads

+ 2 Situational Items Thornmail, Quicksilver Sash, Frozen Mallet, Zeke's Harbinger, and if their Akali, Evelynn, Twitch doing very well than Hextech Sweeper.

Jax choice of items start at loading screen. Once again JAX choice of items start at loading screen, where you can see your enemy champions.

Tell your team, you will get mid turret

You have to count how many pure AD,AP and hybrid champs are there.

1. If there are 3 normal AP champs & 2 AD champs, than u can start with Pickaxe, Cloth Armor, Health Potion and than rush Hextech Gunblade and than core items.

2. If there are 3 or more AP champs with hard CC , only CC which Jax hates = Snare from Morgana and Lux than u would definitely need to start with Negatron Cloak and Null-Magic Mantle so that u can convert them to Quicksilver Sash as ur first item with Mercury's Treads and than ur core items.

3. If there are 3 or more pure AD auto attack champs e.g Gangplank, Talon, Riven, Tryndamere, Sion, Garen, Master Yi, Nocturne, Xin Zhao
Than your starting items should be Chain Vest, Cloth Armor, Cloth Armor, Health Potion
Your first Item will be Thornmail & Ninja Tabi after these 2 items you can go your core build + last item of your choice.

4. In very rare cases 3 or more TANKS like Alistar, Rammus, Yorick, Sion, Garen who only stack hp+armor than ur core build + Kitae's Bloodrazor + Tiamat

NOTES

1. Yes i dont buy Boots in the start instead i like to go with the counterpart of boots i.e Cloth Armor or Null-Magic Mantle, because you are getting middle turret first and than you will go top. Cloth Armor or Null-Magic Mantle will help u alot more than juz Boots

2. Yes i am not a big fan of Guinsoo's Rageblade instead i rather get Zeke's Harbinger.

Abyssal Mask and Zeke's Harbinger work wonders together for you and your Team.

1. Start fight with the active of Hextech Gunblade and than Leap Strike + Empower.
2. Don't die unnecessary, teleport back to base.
3. After lvl 14 or lvl 15 u can fight 1 v 2.
4. Don't forget active of Hextech Gunblade and Ignite 300+410 = 710 free damage.