Jinx is a high-skill champion, with a pretty "tight" learning curve. Although when played properly, can become nearly unstoppable. Jinx excels in pushing with Pow-Pow, the minigun's attack speed, and can unload massive damage in skirmishes using Fishbones, the rocket launcher's range and AoE damage, along with crowd control from Flame Chompers.

Pros!

Capable of becoming one of the highest damaging Attack Damage Carries out there
Considerable amount of crowd-control compared to other ADC's ability-sets
Long range allows you to play safely, while still being useful
Ultimate gives you GLOBAL map aggression, keeping your enemies on their feet

Cons!

Skillshots may be difficult to aim for new players
Once an assassin gets in, you will become extremely vulnerable
Like most other ADCs, Jinx is a glass-cannon - tons of damage, little defense
Can be difficult to catch-up if you fall behind

Get Excited!
Whenever a champion or tower that Jinx has dealt damage to within the last 3 seconds is killed or destroyed, she gains 175% Movement Speed that decays over 4 seconds.

This passive is very useful, whether you use it to kite, chase, or make a quick escape after split-pushing. If you underestimate/forget about this ability, you may have janky movements, so be sure to get used to it.

Switcheroo!
TOGGLE OFF—POW-POW, THE MINIGUN: Jinx's basic attacks grant bonus attack speed for 2.5 seconds, stacking up to 3 times. The stacks decay one at a time when she stops attacking with her minigun.
Switching to her Rocket Launcher will not clear any active stacks, but they will not grant attack speed after her first attack.

TOGGLE ON—FISHBONES, THE ROCKET LAUNCHER: Jinx gains bonus attack range and deals 10% AD bonus damage on her attacks, at the cost of mana per attack.
Additionally, her attacks will splash to nearby enemies - dealing full damage to all enemies within 150 unit radius. The bonus damage to her target and the splash damage both scale additively with critical strikes.

Learning when, where, and why to swap weapons is vital to becoming a good Jinx player. As a general rule, you should only use Rockets when wave-clearing or poking from afar. Shooting someone in range for your minigun with a rocket launcher is a very big waste, the bonus attack speed is more useful than the slight damage bonus. Try to kite with Rockets, but if the enemy gets to close, swap!

Zap!
ACTIVE: After a short delay, Jinx fires a shock blast that deals physical damage to the first enemy hit, also granting true sight and slowing it for 2 seconds.

Zap! has a slight delay when fired, as well as a short travel time. Take your enemy's movements into consideration... "Study them." If you're opponent is dodging often, try to predict which way they'll move. If they are oblivious, keep firing directly at them. Lastly, if an enemy is near a wall fire slightly to the other side of him/her. This means that the hostile champion will have to use an escape/dash to dodge it.

Flame Chompers!
Jinx tosses out 3 chompers that, once armed, explode on contact with enemy champions dealing magic damage over 1.5 seconds to nearby enemies. The champion that sets off the chomper is also rooted the same duration. Chompers explode automatically after 5 seconds.

Often times, Flame chompers are Jinx's one line of defense. A jack-of-all-trades ability, it can be used to flee, chase, or block off paths from approaching foes.

Super Mega Death Rocket!
Jinx fires a rocket that gains damage over the first second it travels. It explodes on the first enemy champion hit, dealing Physical Damage plus a percentage of the target's missing health. Nearby enemies take 80% damage.

Personally, Jinx's ultimate is one of the reasons I started playing her in the first place. There's nothing more satisfying(or fun!)than blowing up an enemy across the map, or stealing objectives like Baron Nashor/Dragon. Keep in mind that the Projectile itself only explodes when in contact with an enemy champion. Often I see Jinx players use their ultimate against people with full/almost full health, which is just silly. ONLY use if you're confident it can deal significant enough damage to kill, steal, or grab an assist on the target.

I put a simple statement about both masteries and runes above, just go read there!

Doran's Blade
The basic starter for all ADC's, consider grabbing two for extra health and sustain. Sell for better items later on.

Boots of Speed/Berkzerkers Greaves
Boots of speed are a good option if you cant quite afford a B.F Sword yet, most likely along with either a Pickaxe or another Doran's Blade. Boots help you dodge attacks, and give a noticeable boost in speed compared to those who do not have boots. Upgrade boots later on, around the time you reach your third item, maybe even earlier if you feel being faster is important.


Infinity Edge
Infinity Edge is pretty much a requirement on all Marksmen, the damage and critcal chance it offers is massively important, and may decide which ADC beats the other one. When combined with another crit item, you become a force to be reckoned with.


Lifesteal
Blade of the Ruined King OR The Bloodthirster
I feel that both lifesteal items are AMAZING and definitely viable on Jinx. Usually if your enemies build health, I buy BoRK for the shredding and kiting potential. Otherwise go with Bloodthirster, which gives an extreme amount of lifesteal and attack damage, but nothing else. If you're absolutely stomping the enemy, why not both?


Attack Speed/Crit
Statikk shiv OR Phantom Dancer
Similarly to the lifesteal options above, both options are excellent and work well. Statikk Shiv allows you to do what a Phantom Dancer does, but slightly less good of stats. However, Statikk's passive can create a hearty chunk of damage that Phantom Dancer can not, making it still worth contemplating.


Defensive Options
Guardian Angel, Dervish Blade, or Banshee's Veil
All three of these items are great, though often situational. I would suggest Dervish if you're up against pesky enemies such as Zed, so you can negate his ultimate. Banshee's Veil works well against champions whose abilities just ruin your day, such as Blitzcranks pull or Karthus's ultimate. If you're behind, grab Guardian Angel - It could easily save your life. Watchout though, it has a very long cooldown.


Other
Yomuu's Ghostblade and Runaan's Hurricane
Yomuu's works well with champions who attack/all-in at a certain time, such as Twitch, Vayne, or even Graves. Jinx never really has that moment, and there's just better items for her. Runaan's just isn't that good, it does instantly give you 3 stacks on your minigun, but like I said, better items.

My name is Slyfur, i'm currently Gold looking for Platinum in Season 5.
I main attack damage carries, Quinn, Graves, and Jinx are a few of my favorites.
This is my second guide on Mobafire, but the first is archived garbage. I had to figure out how all this stuff works, and it took me awhile. Any feedback, postive or negative, is much appreciated, hopefully I get better at this stuff in the future. Thanks for reading, and feel free to add me so we can play sometime. ;)