Read entire guide please :D

This guide and everything in it was written entirely by me and my experiances with Caitlyn.
I did this on a whim and it took a few hours, please excuse any gramatical errors, and the lack of pictures.

I do suggest looking at Caitlyn - In-Depth Guide by HoLyHiraKo if you'd like to see some examples of heroes to lane with, pictures of walls you can and cannot jump over, and a nice little section for tips on heroes you may lane mid against. It's an excellent guide itself.

If you have any questions about my build, contact me through comments or in-game. My name is in the introduction.
Comment if you dislike and try the build out before you dislike it!!!

Hello there.
I'm JenovaLi�e in-game. (JenovaLi(hold alt, press 159 on numpad to enter the 'f' I use)e)

I've been playing Caitlyn since she came out and she is one of my favorite... No, she IS my favorite champion to play. Mmmm, a sniper, how delightful! And what's that? Cupcakes! Oh my, a much better way of feeding their team!!!

Statistics: Usually, I only have 1-4 deaths always have at least a 2.0 k/d ratio with quite a bit of assists. 9/1/9 8/4/4 15/2/17 12/7/19 13/0/7 are a few of the games I've played. Depends on our team composition and theirs and how well we're doing as a team.

Alright, so I've seen quite a bit of people that go attack speed for Cait with a Madred/P-dancer etc. I believe they could have a much higher damage potential with a heavier AD build and I'll explain my reasoning behind it. Every 8 attacks she hits for 150% damage against enemy champions. Yes, attack speed does get you to hit that 150% more often. However, you do hit much, much harder with pure AD, some crit, and a little armor pen. I've hit squishies, with auto attack, 1000 on normal hits (crit) and 1600-1800(crit) with Headshot.

Her ulti Ace in the Hole is capable of dropping their carries (ashe or TF for example) half to 3/4s of their full health. Rather than 1/4 an attack speed build offer. I only mention squishies because they should be your priority to kill. Although, I've had no problem killing armor tanks such as rammus/malphite without a madred's etc or any other items deviating from this build.

Pros:
-Awesome harrass early game due to Headshot and Piltover Peacemaker
-Great at farming minions
-Insane range on standard attacks (650)
-Can be effective mid or side lane
- Ace in the Hole is nice for picking people off or indirectly initiating
-Good at escaping, in my opinion, with positioned traps, net, summoner abilities.
-Shines late game

Cons:
-Extremely squishy (usually targeted)
-Ulti can be blocked by other champions
-Visible traps! and only 2 allowed!!! (make them like nidalee's traps please) <3

Other than that, I don't really see any other cons if positioned well and played correctly.

I run with Flash and Cleanse. I'll explain.

Flash. Gives you an extra 'jump' along with 90 Caliber Net to either escape, or chase. Great for getting that person who just popped ghost etc. into range for your ulti, Ace in the Hole.

Cleanse. Oh how I love cleanse. I cannot imagine playing her without it. It's saved me so many times from easily avoidable deaths. In case you get caught from a stun/taunt/crowd control, cleanse->net->trap->flash. I cannot count how many ganks I've escaped from because of this. Rammus taunt, no problem. Ashe's arrow, no problem. Laning against Anivia mid and you get caught with a stun, no problem. Typically, I only get 1-4 deaths a game. A well timed cleanse definately contributes to it.

Other viable summoner spells are:

Ghost Another ability for escaping or chasing. Great, I grab this if I don't grab cleanse.

Clairvoyance I've experimented with this and it's actually nice to prevent ganks on your team with some extra map awareness, to check possible baron, dragon attempts, their blue/red buff, and my favorite, pop it in the Fog of War (black part of map you can't see) to ensure kills with ulti if they manage to escape... or so they think!

I would not use any other summoner spells than these four. I think she needs the extra escape/chase these summoner spells provide in order to prevent deaths or ensure kills.
However, people have their preferences and may want to grab exhaust or teleport, that is fine. This is just how I play Caitlyn.

I've tried out quite a few different rune builds, such as all crit runes or attack speed for quins and marks, but Armor Penetration is by far superior. I've tried dodge runes w/ 9 points in Defense tree etc and quite a few others just to test or mess around with different possibilities.

Runes:
Greater Mark of Desolationx9
Greater Quintessence of Desolationx3
Greater Seal of Replenishmentx9
Greater Glyph of Scaling Mana Regenerationx9
Totals up to:
-25 Armor Pen
-13 Mana Regen per 5 at 18
-3.7 Flat Mana Regen

I roll Armor Pen to hit harder. Early game, it hits through armor, the little everyone has, and helps with late game to hit those tanks harder.
I get MP5 to keep my mana up so I can spam my Piltover Peacemaker moderately (1 per creep wave aproximately) and always have mana for 90 Caliber Net. I won't have to buy MP5 items such as a Meki Pendant. It keeps up your harrass capability and helps with multiple minion kills/pushing their tower.

Other runes for Glyphs that are viable of course are Greater Glyph of Cooldown Reduction for some Flat Cooldown Reduction. I don't run anything else with Caitlyn, but I prefer MP5 over this.


Masteries:
Masteries is pretty straight forward with 21/0/9.
I grab everything an AD dps would want in Offense and grab some utility for the increased buff durations when I do grab them, extra 5% exp is always nice, and you can grab imp ghost if you chose it as a summoner spell.
You can go the 9 in defense but I find utility has more to offer since you should not be getting hit in team fights anyways with the range Caitlyn has.

Now to the items! Finally huh?
Core Build:


Item Sequence:

Optional Items (Your choice):


Early Game:
Alright, so I grab Doran's Blade and a Health Potion and usually grab mid if possible. Sometimes you get some babies that cry about it, or won't give it up. Maybe someone is better attuned for mid with a better ulti for ganks or w/e the case may be. It's okay, go to a side lane. Caitlyn can excel in these just as well if paired with the right champions. Lane with someone who has a nice CC ability, if possible, like a snare or stun for easiest kills/first blood, or a melee since it's easy to keep the opposing champions at bay with your range. Harrass them with your Piltover Peacemaker and Headshot. Use them to last hit minions if their champions are not in range. If on a side lane, DO attack minions from brush!! This gives your passive 2 stacks instead of 1!! Which is harder hits every 4 attacks instead of 8!
Try not to back until you have some bulk in your wallet to buy Berserker's Greaves and another Doran's Blade. If you can stay in lane long enough to grab a B. F. Sword, by all means, please do. It gives such a big damage boost to your Q and R abilities. If your mid, definately assist in ganks if their mid leaves lane or hugs their tower cuz they've taken too much damage from your annoying harrass.

Mid Game:
Depending on players and game, people will start to roam more due to tower losses or are just ganking. Stick with your CC buddy and team and do NOT roam alone. Damage the enemies can deal is starting to pick up and you are very squishy and susceptable to CC, stay behind team mates in team fights and back up when needed. Grab another B. F. Sword or 2 during this time. Depends on how well you farm creeps and how many kills you've managed to get. I usually have about 30 more minion kills than the next highest in game which is easily obtained if you stay in your lane, defend your towers. Of course, it all depends on the game and the players in it. Maybe grab your Black Cleaver during this time.

Late Game:
Sweet, you hit their squishies very hard now and people should fear you now. You will be one of the priorities to kill in team fights. You should have your Bloodthirster and your Infinity Edge and begin working on a Banshee's Veil. Same thing as mid game, stick with your team, and do not roam alone. You may not make it to a 6th item(most games don't last that long), but if it does, I usually get another Bloodthirster. Sometimes I'll grab a Phantom Dancer because of the move speed, extra crit chance, and AS, but it all depends on the mood I'm in. I usually prefer the lifesteal another Bloodthirster gives. A Last Whisper if they've got tons of armor items.


As for the item sequence, you may ask, WHY THREE B.F. SWORDS FIRST??? I've tried all three B.F. Sword related items all in different orders in multiple games and most balanced is Black Cleaver -> Bloodthirster -> Inf Edge. I've had the most success grabbing 3 B.F. Swords first and then upgrading later INSTEAD of upgrading each individualy and in order. It gives the most damage to your abilities and makes you hit very hard with your ulti.

All this is still situational of course. Upgrade to Black Cleaver earlier and grab more Armor Penetration items if those tanks are giving you trouble or if they have 2-3 good tanks.
If you keep getting CC'd and find yourself dying because of it, grab a Banshee's Veil after a few B. F. Sword. Damage is the most important!!! A B. F. Sword takes priority over other lesser items such as Doran's Blade or Vampiric Sceptor or Dagger.

I've also skipped Banshee's a few games for kicks and giggles to see some really high numbers or if I have a team that plays very well together and keeps the enemy champions away from me.

A few nifty Tips & Tricks for abilities:

Yordle Snap Trap:
Keep your traps in places you'll run to or in brush to prevent ganks on you etc. Always have an escape plan!!! You can always place one down if needed to survive. Be aware of which trap will disappear if you place another and try to keep 2 down mid/late game. If I'm mid, I do not use traps early game because they cause you to run low on mana and prevent you from semi-spamming your Q ability. In side lanes, I always grab at level 4 and place one in the river brush and another on side brush.

Piltover Peacemaker:
Your Q ability. Fire in a line to hit all minions to keep them pushed and away from your tower. We don't want our towers snagging OUR minion kills, now do we? They could be gold for you or your lane buddy. Hit enemy champions to harrass as well. This is much easier with a lane partner that has some form of CC (snare,stun etc.). It deals less damage with each extra minion or champion you hit. If you can hit JUST their champions, it will deal more damage to them, causing them to back if harrassed enough. This will lead to an exp lead if they have to back or you keep them pinned to tower with their creeps pushing towards yours.

90 Caliber Net:
Great escape or chase ability. You can use this to hop back and slow someone chasing you. You may also use this to hop towards enemies by shooting it away from them to get into range to smack them with your passive or get into range for your ulti. There are walls you can hop over as well to escape. This does not work for ALL walls, only the smaller ones. Larger walls will cause you to hop into it, waste time, and you'll most likely die if your trying to run from enemy champions. Also for slowing someone so a team mate can snag a kill if they will escape otherwise if you don't. Note that this may put you out of range for auto attacks and other abilities. For Melee champions this is awesome!!! I've lived from Tryndameres by using this along with traps and kiting them while dpsing them down and using ulti to snag the kill when they try to run. This ability works well in conjunction with your summoner abilities.

Ace in the Hole:
What makes Caitlyn the sniper she is. If only it could reach across map similar to Karth's ulti :D Nevertheless, this is an awesome ability and hits their squishies extremely hard.
After you start getting some damage, it's fairly easy to snag that last hit to get that kill you worked so hard on. After all, it'd be a shame if we let them get away. This ulti is highly situational and depends heavily on postion of you, your target, and the other champions on the opposing team. Typically, save it for the end of a team fight, to pick someone off as they run out of range or into their tower's range. Their other team mates CAN block a it to prevent you from getting the kill. Try to use it when you have a clear shot.
Sometimes I will use it first to take someone down to 1/2 or 1/4 health to get my team mates a kill. Other times one of their squishies will block it to save a team mate and take 3/4 or 1/2 damage to their health and die in their place, which kinda makes me chuckle :P Try not to tickle their tanks with this ability :P but can still be used to last hit/kill a tank if they're low enough.

I usually run with a friend who is either Malphite/Sion(AD)/Ryze for side lanes. Holysury is his name and he's in half or most of my games. So I am never alone, and you shouldn't be, while roaming around or ganking. I will not pick Caitlyn if two-three people lock in Miss Fortune/Ashe/Master Yi/Trynd(just some examples). That would simply be too much AD. Typical setup for success is up to 2 AD, 2 AP and 1-2 tanks with 3-4 of the champion's on your team having some form of CC. Of course, any combination of champions may or may not be successful.

-You're not a tank! Don't initiate!
-Keep range between you and your target!
-Don't target their tanks first!
-Just play smart and you should have no problem dominating games with Caitlyn :D

I hope you like my build and I gave enough info! Enjoy her as much as I do ^-^

Again.
If you have any questions about my build, contact me through comments or in-game. My name is in the introduction.
Comment if you dislike and please try the build out before you dislike it!!!

Any other options you choose for runes/abilities/items are entirely up to you.
This is just my build style for Caitlyn and it works for me very well :)