I am fairly recent to this game, but one thing I have noticed is that Caitlyn is a monster. I am always terrified to lane against her, and I love playing as her. She can completely dominate a lane, and scales very well into late game. So I decided to spread the love and create this guide.

Pros:
-Fantastic lane control
-Excellent Range
-Great pusher/farmer
-Carries well in late game
-Range underestimate, leads to early game kills


Cons:
-Quite squishy
-Awkward mid game while building items
-Thornmail is hard to get over

I build Caitlyn's rune set to make her early laning even stronger. I do this so that she can get fed and her mid game will be a little stronger. This is why I go for flat runes over scaling runes.


Greater Mark of Desolation
Standard AD Carry stuff, allows you to deal good amounts of damage early

Greater Seal of Replenishment
These allow Caitlyn to keep putting out traps to maintain brush control, as well as allowing her to harass when she needs to.

Greater Glyph of Cooldown Reduction
Late in the game, you will notice you are using your skills less and less, which is why I go for flat cooldown (and flat mana regen for that matter), this way early game when your peacemaker and traps are your bread and butter, they will be off cooldown at the soonest possible moment.

Greater Quintessence of Desolation
Same as the marks, great for any AD Carry.

I use a pretty standard 21/0/9 AD build. Again I focus on her laning presence so I do take the mana and mana regen buffs out of the utility tree.

I think is where the biggest differences of opinion come in. Because of Caitlyn's passive, I've seen a lot of builds go straight for Zeal. However, I have found that Berserker's Greaves Give enough attack speed, and that you really want the damage output to go up early. There have been plenty of times where I rushed a B. F. Sword even before upgrading my boots.Hitting that hard early game can really surprise enemy summoners and get you kills.

I go for Bloodthirster first because it gives Caitlyn a way to sustain, and helps her to stay alive during the mid game. Afterwards I do go ahead and grab the Zeal, because now she is doing enough damage to really see the difference. This also makes her a monster at pushing and downing towers.

After this point in the game, the build order will probably vary quite a bit. I have Quicksilver Sash last in the build order, but I usually grab one much earlier. It's very cheap, and provides a lot of survivability for the price. And lord knows Cait needs it. The rest of the build is pretty standard AD carry stuff. Lots of damage and attack speed.

Note that Wriggle's Lantern is also a fantastic choice as well, it it's like a mini bloodthirster as well as allowing you to ward and giving you some defense. It's not just for junglers folks.

Headshot

Cait's passive. Very important to keep track of when this is going to come up. Fantastic for last hitting and harassment. Shooting from the brush is good of course, however don't take any risks to do it. You'll be fine with that sweet, sweet damage every 8th hit, I promise.

Piltover Peacemaker

Caitlyn's most dreaded ability. This is the skill that will cause enemy summoners to pull their hair out in lane. It always goes further than they think, and always hits harder than they think. Learning how to lead with this skill will determine how well you do in the early game. Remember that this skill has a very long range, and make sure to use it when you know they are too far to punish you for it, and try to make sure it doesn't go through minions for maximum damage. This skill is Caitlyn's bread and butter, and should always be maxed first.

Yordle Snap Trap

I take this skill first, because it prides so much to the laning phase. You should almost always have three of these out. You can place it behind the enemies to keep them from escaping, or behind you to cover your own. Definitely have on in the brush at river, because junglers (and mid) like to come from there, and your trap will catch them most of the time and straight out prevent ganks. Having them in the lane brush can also make sure that the enemy doesn't catch you unawares. These traps do quite a bit of damage at level one, and if you are laning with someone that has a stun (like Taric), it can sometimes be enough for a kill. Let them land their stun, and then immediately place your trap under the feet of your enemy. By the time the stun goes away, the trap will be active and catch them, and you can just auto attack them down.

90 Caliber Net

This skill is a great escape tool. Always keep in mind that this skill can push Caitlyn through small walls in the jungle, for instance the back wall of dragon. Knowing these places can guarantee you an escape.

Ace in the Hole

Caitlyn's Ultimate, and it is no slouch. Scales crazy well with AD, and is actually one of the reasons I rush Bloodthirster. If you get an early AD item like that, this skill can easily take out a third of a squishy champs health, which, conveniently, is about when they start running away. Don't be scared to shoot this when you're not sure it will pick up the kill, it does have a relatively short cooldown. Most guides will tell you not to use this in team fights because it can be interrupted by enemy champions. I see their point, but in my experience if someone does jump in front of it, my team will pick up the kill on that person instead because of the mass damage it does, and the fact that the martyr threw themselves out of position. And often times (especially in solo queue) enemy champions will get out of the way of the line just from reaction. Even so, definitely try to position yourself so that the enemy champions will have to go significantly out of their way to take the shot.

I take Flash because, well, it's flash. positions you in team fights, used to chase and escape, and just all around good. Apparently some nerfs are coming down on it soon, so I may update this accordingly.

Exhaust is up for debate for me. using it offensively is not always realistic because it has a shorter range than you do, and using it defensively is lackluster at best. However, it definitely has the power to get unexpected kills because that melee carry thought he had the damage to take you out, or didn't start running quite soon enough, especially early game.

There are two other possible options in place of Exhaust (and if you take them, besure to respec that mastery point!)

The first is Ghost. Gives you yet another escape option which is always helpful for squishies, however since Cait usually hangs around in the back of the team, you'll find yourself not using it very much.

Teleport is the second, and is probably my most used this side of Exhaust. The spell gives amazing utility. Let's be honest, as AD carries we love to farm, and sometimes a team fight breaks out on the other side of the map while we are farming. This spell solves that problem. Early game it also allows you to have staggering lane presence, as going back to buy takes no time, and then you are back in lane, stronger, and fully healed. That can be enough to turn a lane at times.


Again there is about to be some major adjustments to the summoner spells, so when that happens I will test them out and update!

To summarize, if you want to play a champion that can farm her tail off and push like crazy, but also be able to carry a team very well late game, Caitlyn is for you. Just be wary of her squishiness, and the other team's composition. Buy your items accordingly.