First off, this is the first build I have ever made. Any pointers are appreciated, some pointers I will try, others I may just ignore depending on what the pointer is. Another thing, looking up my profile I may not look like anything special. Most of my games have been played in custom games with friends. I rarely queue in a normal unless I'm with friends.

I started playing League years ago (back when Morde was OP as F). Then I took a break from the game for a while and came back to it about a year and a half ago. Since then I have gotten on only when friends were online, or to get the daily win out of the way. I have tried many different champs, and have enjoyed some of them, hated others, and just downright despised a couple.

Just recently I decided to play Cait. It was a week she was free, and I instantly fell in love with her (figuratively.... as far as you know.) I love her play style. It goes so well with how I tend to play. I have played her more and more and rather quickly I came up with a build that does very well (for me anyways). I'm told that she is strong early and late, but falls through and things get tough in mid-game. I'm not to sure about that, seeing as I haven't had any problem mid game. Infact it's about midgame that my game really starts to take off. How ever I'll go over all that here in a bit.

Hope you enjoy, hope some of yall try this build out and enjoy it. Tips from pro Cait players greatly appreciated and encouraged.

This build is subject to change as I learn more.

So, as most of you know Cait is a ranged ADC with the longest auto attack range in the game. This allows for very good farming, poking, harrassing, and so forth. This range also makes it easier for anyone to play more defensively and stay out of range from other players, while at the same time zoning them back.

Cait's early game is fun, and fairly strong with a good support by your side. I find that she can do well going into mid game, and great into late. She has good range on her abilities, a trap that is very useful if properly used, and 2 escapes if you have flash (which you should). Not to mention her ult can be used to take down enemies from far off.

These runes will give you that extra boost you need early game to last hit the minions, and work on your CS. I have seen some people use Arm pen inplace of these, how ever early game minions already have very low armor, meaning you don't need the Arm pen. And late game the champs have such high armor that the Arm pen runes don't effect much. Also after some testing I have found I do on average 5-10 points of damage more with these instead of Arm pen early game.

As the ADC, you're going to be up against another ADC, so you want some defense to combat this threat. With out these runs the apposing ADC will be able to zone you out of the lane much easier. Especially seeing as Cait starts out with a normal 16 armor

Just because the main damage dealer in your lane is the ADC, doesn't mean you can slack off and not worry about their support. Some supports can still do the damage needed to secure the kill for their ADC, even if the support has no +AP items..

These Quints are very helpful in keeping you in lane longer. 6% may not seem like a whole lot, but after a while it can make the difference on wether or not you are staying in the lane to farm, or going B because you took to much damage.

This should be an obvious choice in your build. Just about every ADC runs around with a Flash, and being able to have that 15 sec sooner is good at times. This could mean the difference between you getting away, or getting closer to snag that kill.

I put a point into this because I have found that Barrier works much better then ignite does. There have been many times where Barrier has been what saves me from duel ignites, or keeps me alive just long enough during a tower dive to get a kill out of it.

I don't really ever see this put into many builds. Though I have found it helpful when getting back to lane quicker. Or if I'm lucky I'm being chased, just far enough that I'm not being hit and right before someone gets within range that buff kicks in and I'm able to get away. Though that's rare.

Cait's abilities work best during early-mid game. Falling short into the late game causing you to rely mostly on your auto attacks. This isn't saying her abilities are useless late game. They are good for dealing that extra bit of damage.
This is Cait's main ability (her Q), and should be maxed first. Early game this is useful for poking the enemy, or helping to clear a minion wave if it's getting to close to your tower. It has a very long range, so even if the enemy is outside the range of your Auto attack, you can still probably hit them with this. Keep in mind though that the ability gets weaker as it passes through enemies. So shooting through a minion wave will make this attack do very little damage by the time it hits your intended target. Ontop of that, with it's 10 sec CD, and 50 mana cost, it is very easy to spam this a little to much and blow through your mana pool. Use this sparingly so you have mana for the times you really need it.
This is the second ability of Cait's (her W). Its damage is modified by AP, and as such this ability is usually leveled last. This ability is usefull in snaring the enemy in a bush long enough for you to poke at them, or foiling a bot gank by placing a trap in the river bush. This can even be used when trying to run away by placing it in-front of you, and then running on past requiring who ever is chasing you to go around or to be snared. Just don't bother with it if the enemy is kinda close, placing it does cause your character to stop running briefly.
The third ability (her E) in Cait's arsenal is a 90 cal net. The net itself does a little bit of damage, but that isn't what makes this ability nice. What does how ever is the knock-back it does to you when fired. This knock-back can be used in retreating, or catching up. It can send you through walls for a surprise attack, or to get away from chasing enemies. This combined with your flash gives you 2 good escapes, or gap closers. I usually level this ability second.
This is Cait's ult (her R). You see that low health enemy running away? He looks like he is going to get away doesn't it? Not with this ult at your disposal though. As long as you can see the champ to lock onto him, there is next to no way he will be able to get out of it's range. This ability is great for last hitting a fleeing champion securing another kill for you and your team. The downside to this how ever is that it can be blocked by other champions. Though with it's quick bullet speed the blocking champions need to be close by the bullets path, or have their flash up to be able to get in its way quick enough. This ability doesn't always have to be used for last hitting either. It can also be used at the start of a team fight. With the large amount of damage it deals, it could be enough for your team to get the first kill of a team fight almost right off the bat turning a 5v5 into a 5v4 and giving your team an advantage.

Now here is the hard part of any build. Figuring out what items you're going to get. If you don't get the right items your champion won't preform at their best. The wrong items will make everyone hate and despise you, and this will result in them not sharing cookies with you after the game. So remember, get the right items and you get a cookie at the end.

I usually start with a Doran's Blade. This item gives me a bit of HP, some extra AD, and a passive +5 HP healed on each auto attack. That combined with the +6% lifesteal can equate to enough health to keep you in the game longer. While being able to do enough damage to last hit minions as protocol.

Ideally I try to stay in lane for as long as possible. There are times where I am forced out sooner and this does slow things down. I have learned that if you are able to stay in the lane long enough, it's best to get a B. F. Sword and Boots the first time you go shop. This gives you some extra movespeed, and a great increase in power allowing you to control your lane more effectively.

How ever there are times as I said when I'm pushed out of my lane sooner then I would like. At these times I do change it up by buying a Long Sword and Boots when I head B for the first time. This usually gives me the extra bit of damage and maneuverability to farm up the needed 1550 gold to go back and buy a B. F. Sword. I have seen some Caits going after a second Doran's Blade. I personally think this practice is stupid. It gives you a bit more HP, and a bit more AD. How ever by the time you go B for the first time you are usually lvl 2 or 3, resulting in the +5hp per hit to be pointless. Ontop of that the Doran's Blade doesn't build into anything. Meaning you just spent 475g on an item you will have to sell for much less later on, ending up in you losing gold that could have been used to buy an item your just 100-150g shy of getting

Once I have the B. F. Sword I set my sights on upgrading my boots. I now have the damage to easily last hit minions, and control my lane. The next item I go for is Berserker's Greaves. This item allows me to run a bit faster, and attack quicker making it easier to switch between minions that are low on health, and the enemy champs that have ventured to close.

Once my attack speed is upped a bit I can get back to working on my damage. Now I have seen many people talking about how Infinity Edge should be rushed, and is the way to go. That's great and all, but what use is that extra damage when you don't have the sustain? That's why I also get Bloodthirster next. This item gives just as much AD, and it gives a nice bit of lifesteal all right off the bat. As a bonus the item becomes more powerful as you kill things with it, ending with even more AD then the IE has, and even more lifesteal to keep you sustained.

Once you have Bloodthirster, you have plenty of AD to make things hurt, and farm up your CS with ease. Now you need to be able to dish out that damage more effectively. This is where the Runaan's Hurricane comes into play. The massive attack speed increase really makes a difference. Not to mention the 2 extra bolts that fire out with every auto attack to any other enemies within range. The bolts also apply any on hit effects, which I do believe includes lifesteal. meaning that not only are you getting HP back from your standard auto attack, but from the 2 bolts aswell resulting in you having almost double the lifesteal.

After Runaan's Hurricane is acquired your build is just about set. Now you can start working on upping that damage even more. If you're fed and owning just about everyone you come across Blade of the Ruined King is a nice addition. This item will give you a bit more AD, some more attack speed, and more lifesteal. Not to mention the bonus effects you up-tain from this item. Though if you get to a point where you need more damage then start building Infinity Edge. This will give you the damage you need to possibly turn the tide of a team fight for your team. Combined with Bloodthirster and Runaan's Hurricane, the increase in damage really starts to pay off in the lifesteal

The last item is always a toss up. If you're trying to figure out what to get for your last item, then it's end game and you're already pretty well fed. Depending on what the enemy team is doing you have 2 good choice.
1. If they aren't all that beefy then you can go with a Phantom Dancer. The added attack speed, run speed, and crit make every team fight a blast. not to mention you will no longer have to worry about minions getting in your way.
2. if the enemy team is fairly beefy, then Last Whisper makes taking them down much easier. You won't get up into the 2.0+ attack speed, but you will still be doing a lot of damage to everyone.

Playing Cait is fun. She is a strong ADC, and if played right she can actually do what a true ADC is suppose to.

Early Game
Focus on last hitting creeps, never stand still long enough for the enemy to land an attack on you. These are a couple of no-du rules. With Cait's long range you should be able to stand back picking off the creeps as they get low on health, and hitting a champion from time to time when they come in to try and last hit.

As an ADC it is not your job to initiate a fight. This will cause the enemy to focus you, and more then likely result in your death. If you're lucky the support got it and not the enemy ADC. The last thing you want is the apposing ADC to be up a kill, and while you're dead they will also pull ahead on CS. stay in the back, watch what is going on and eventually you will see your opening to strike when they decide to engage. If your support has some sort of CC, then watch them and only go in when they have snared, or grabbed the enemy. Never chase out past your creep wave, and try to stay in the bushes. This is just in case the enemy jungler has shown up he will have some minions to run through to get to you.

mid Game
By this point you should almost have your core build. You have good damage, sustain, and attack speed. By mid game people are starting to roam, group up and this is where team fights start. Again just like early game you never want to engage first. Always run back behind everyone and let them engage. With your long range you should be able to stay outside of the team fight avoiding most AoE damage and still be able to make the enemy hurt. There are some that say Cait's mid game is weak, but with this build I haven't had a problem with mid game.

As your team moves in to engage the other, now would be a good time to use your Q while they are all grouped up. Allowing you to deal damage to several enemies at once. If you're able to with out getting into trouble, place a trap down behind an enemy so if they decide to run they will run into it. Or if they are stunned then place the trap under them. As soon as they come out of the stun the trap should spring and they are stuck there for a moment longer. Cait's ult can be used in 1 of two ways during team fights. Usually mid game it's best to use the ult at the start to get a nice junk of damage in on someone that will help kill that person quicker. As the game progresses you will learn how well your team handles team fights, and adjust when you use the ult. If you're team controls the team fights then save the ult for any would be escapees trying to run away.

Late Game
By the time late game rolls around, you should have your core build and working on the last 2 items. With your core build you do a considerable amount of damage to not only your target, but 2 other targets nearby. With the high attack speed Cait will have, this damage can add up very quickly and end up with your team dominating most of the team fights that break out. At this point in the game you should also be powerful enough to 2 man baron, possibly even solo it depending on how fed you are at the time. Creep waves are annihilated in a couple of seconds, and most opposing ADC can't stand up to the quick damage you're dishing out, stacked with the life steal on top of it.