Jax is a cool champion, unbelivable good 1v1, good at all stages in game. My favorite champion...

For runes its more options

I go on AD marks cause it gives some HP boost because of his passive, and ofc AD gives boost to his Leap strike, so its useful for early game mostly. You can also do on MP so you will deal more damage with Leap strike but dont give any health boost wich might be handy in early game.

Seals, there is no discussion, you must go on dodge, cuase of his E...

On Glyphs, I usualy go for MR, you can use flat MR or not, but i highly recommend MR wich is jaxs weak point,but ur ultimate gives u some so you should have enough of MR in late game, thanks to runes and ultimate skill.

For Quints i use flat AD for the same reason as Marks, here u have some options, you can maybe use flat AP or Dodge, totally youre call, all gives about the same quality.

For Marks and Quints i have to say its better to use AD cause you are auto attacker after all, and you have lots of lifesteak in mid-late game so that is very good with AD.

The new masteries i go straight offense, maybe there is a option to go a little on def too...

I start with a Cloth armor and 5 potions for stability in lane, cause u already have 78 ad with this rune build and 5ap of masteries

Than i go on boots ninja tabi-dodge and armor, everythink crystal clear

Next i go on Hextech Gunblade straight, it may take a little long but its useful, very useful

The next item its Rageblade wich is also normal on jax so theres no explanation why i use it...

4th item is warmongs for great health and late cause of atmas u will gain lots of AD

Next item is Abyssal Scepter or Atmas Impaler, depends on enemy team more AD or AP damage, but u have to buy both sooner or later they are both a must.

Last item is Lich Bane, i sell Rageblade and buy lich bane cause it gives u nice AP, mama, MR and great passive.

Thats all items, with this build u can kill anyone with hiw final build easyly, except maybe tryinda with his ulti but he shouldnt get fed so much...

Leap strike
Awsome skill for ganking, assasinating, harrasing, turret diving, last hitting... AWSOME

Empowerment
Good boost for Q+W combos wich deal huge damage

Counter strike
AoE stun. There i use Q+W+E combo for insta kill, u move around enemy minions so the shot YOU and you eventualy dodge so this skill activates, now you have to find an enemy in 7 sec you use Q+W on him, than instant stun + 3 hits its around 1200+ damage than ignite and run after him and again Q+W (possibly E if its active) wich comes around 2000 damage if enemys not dead you shot him with Hextech Gunblade active so he is slow, now u auto attack him and Q+W when possible. This comes 3000-4000 TOTAL DAMAGE, kills almost every targer Guaranteed.

This is for late game ofc, when all items are bought, earlyer you deal little less damage ofc :)

Relentless assault
Use it when in teamfights or fighting against AP champion, AWSOME PASSIVE, active is somekind ussles but ok

You pick Q first than W, than u max first Q than W for better leap strike damage wich is youre best weapon, E is not really important it does small damage and the stun is always the same lenght so you need it to boost last, ulti ofc when possible.

Flash
For chasing and pursuiting, almost a must for every champion

Surge
Surge is great spell for jax, it gives u AP and att speed, exactly what u need and i think its a best spell for jax. Whenever u get in fight u should activate this spell and just spam youre w and e whenever u can and you will get most kills...

Pros:
Great 1v1
Good lifesteal, almost never goes back
Great farmer form lvl6 on
Good damage, and lots of life
... probably some more but i forgot

Cons:
In teamfights easily focused
Many times ganked
You think you are god when u easily kill an enemy, but one stun can **** you up really well, so dont chase too much and dont act like ure anbeatable cause youre not :)

U shouldnt jungle until lvl 9-11, than u have to had youre gunblade and now u can jungle everythink u want except baron ofc, u can solo dragon just make sure u dont get ganked, and if any of buffs are avalible u should take it, if noone in youre team needs it more

When u reach full build u can even tank for youre team to lead in team fight and steal deal most of the damage, jax is great iniciator with his leap strike and with this buld u are very very tanky so u can easyliy even 2 or maybe eeven 3v1 and win.

Ty for reading this, i will update it soon with links and pics in it just to find some more time, pls vote it and add a comment to tell me what do you think about my build

This is my first bil and im looking forward to make more.

Oh and sory for my bad english :)

Today i played game on ranked with jax, i was tottaly underfed than i changed a little of my build and i was suddenly unvincible, now this chages will be applyed into build cause i founfd the new build much much better...