TL;DR - The difference between this guide and every other one on this site is that we'll prioritize maxing out "bouncing blades" before "shunpo." The plethora of champions with crowd control makes it more advantageous to be able to harass and farm from afar without fear of being harassed while getting the last hit on the minion.

We prioritize farming from level 1 to level 6. If you get your opponent's health low enough, you can try to land a kill. While exhaust is picked as a summoner spell, ignite is also possible. Exhaust can help you survive or catch up with the enemy, and ignite can sometimes get you that kill that would have otherwise been denied you by an enemy's flash.

===The Details===

First of all thank you in advance for considering this build. After the release of the Dec. 14, 2010 patch, Katarina has both Attack Damage (AD) and Ability Power (AP) scaled into "Bouncing Blade" and her ultimate "Death Lotus." This allows for a hybrid build to be a more powerful option than a pure AP build.

START with 3 Health Potionsand Boots of Speed.

Try to get mid if possible. If laning with another champion, you will have to play defensively and coordinate with your fellow champion. If you're at mid, from level 1-5, focus on last hitting minions and farming. Start harassing at level 6. W->E->auto-attack->Q and run back out of range of your enemy. When your enemy is low on health, use E->R->ignite->W->Q. This is because W usually makes an enemy super cautious. If you kill your enemy at mid or if he teleports back, wander to top or bottom and help them gank. Try to quickly clear your lane before doing so. Use summoner flash to escape mid or team ganks in combination with shunpo or to tower dive for a kill and escaping.

SECOND: Build Hextech Revolverfor 1200 gold on your first trip back. Then finish building Hextech Gunbladeon your second trip back. Remember to use your actives during fights!

THIRD: Finish building Ionian Boots of Lucidity, which is great early on since Katarina has long cooldowns when her abilities are at lower levels. Note: At level 16 and beyond, these can be switched for Sorcerer's Shoes since Katarina's cooldowns are already pretty low when her abilities are maxed out. More importantly, the extra magic penetration provided by those shoes will help in finishing the enemy off. Also, if the opposing team has many CC's, it is definitely a possibility to buy Mercury Treads over both of these boots.

FOURTH: build Rabadon's Deathcap(needlessly large rod first if possible). This item provides a very neat 30% ability power boost passive in addition to a massive 155 AP at less cost than the former Zhonya's Ring. You do lose the ability to not take damage for 2 seconds.

FIFTH: Build Rylai's Crystal Scepterstarting with Giant's Belt for survivability, but if you don't have enough gold upon teleporting back, get what you can afford e.g. amplfying tome.

SIXTH: build either Abyssal Scepter (more preferred)(blasting wand first if possible) OR Void Staff. Prioritize according to how the match is going. Usually abyssal scepter is better than void staff unless you're against a team with lots of magic resistance champions such as galio.

If you can, buy Elixir of Brilliancewith what spare gold you have left. Elixir of Brilliance can also be bought anytime after finishing Hextech Gunblade. However, it's more useful after Rabadon's Deathcap. It is optimal to use when you've maxed out on levels to get the most AP gain.

SEVENTH: build Banshee's Veilfor high CC enemy team OR a lich bane for extra autoattack damage if you can afford it.

EIGHTH: If your game drags on, you can opt to sell one of the items already in your build that you think you can do without such as the abyssal scepter and purchase Guinsoo's Ragebladeif you want to focus on getting rid of turrets and inhibitors, possibly through the backdoor while your teammates distract the enemies. You might also want to get this item earlier if your team is having trouble taking down turrets.

===Alternative Pathway For Better Survivability===
START with Doran's Shieldand 1 Health Potion
SECOND, build Ionian Boots of Lucidity, which is great early on since Katarina has long cooldowns when her abilities are at lower levels.

THIRD, build Rylai's Crystal Scepterstarting with Giant's Belt for survivability, but if you don't have enough gold upon teleporting back, get what you can afford e.g. amplfying tome.

FOURTH, build a Hextech Revolverand finish with a Hextech Gunblade.

FIFTH, build Rabadon's Deathcap(needlessly large rod first if possible). If you have quick fingers and can effectively shunpo onto an enemy champ, use your ultimate and slow the enemy from escaping using Hextech Gunblade's active (in other words, if you have quick fingers) AND can survive without the extra 500 hp afforded by Rylai's Scepter, THEN by all means, build Rabadon's Deathcap first since the 205 AP given by this item trumps the 80 given by Rylai's Scepter.

CONTINUE FROM SIXTH: ABOVE!

===End of Alternative Pathway===

OPTIONAL: You can grab mejai's soulstealerafter boots of speed, but this is only if you're confident you won't die and will be able to stack kills. For pubstomping games, you can get a sword of occultright after mejai's and then follow up with rylai's for survivability and then zonyas for extra AP damage. Finally, you can get void staff and a hextech gunblade provided you have enough gold (credits to Henryus for suggestions for this optional build).

Many also ask if AD is still feasible. Although it is not the best option in my opinion, you can also stack 2 or 3 BF swords, which you can convert to bloodthirsters and/or infinity edge. However, I strongly recommend guinsoo's rageblade somewhere in there if you decide to follow this pathway in order to increase your effectiveness at backdooring.

===Runes & Masteries===

Katarina is a very squishy champion. That being said, it is to your advantage to counter this weak point via runes and masteries. For masteries, I went with mainly defensive specs. Offense went up to archaic knowledge because 15% magic penetration is crucial for a champion, who dishes out the vast majority of her damage as magic damage.

Magic penetration marks are the standard, and shouldn't be changed. Originally, the seals I had focused on dodge; however, after reevaluation, I find it more logical to replace those dodge runes with seals of vitality, which will add a total of 175 health by level 18. This extra health can make the difference between barely escaping alive or dying on the battlefield. I also changed the glyphs from flat AP glyphs to AP by level. By level 6, you will actually have more ability power than you would from flat AP glphys. By level 18, you will triple the amount of AP you get from these glyphs versus from flat AP glyphs, which is the steal.

I went with flat AP quintessences, but these can be substituted for CDR or health if you find those to be better.

===Summoner Spells===

: This is a great ability when using your combo (W)E->R->ignite->(W)Q to ensure a kill especially when an enemy flashes out of range of your ultimate or if your enemy barely manages to get away before you can finish them off.
: This ability works great for either offense or defense. If you need to turret dive to finish off an enemy champion, use shunpo (E) followed by a brief moment of your ult (R) and/or ignite if necessary, then simply flash out of the turret's range of sight if it targets you. It can also be used as an escape tactic if shunpo is on cooldown or if you're being ganked/chased and need the extra distance to prevent being CC'd.

I understand that shunpo automatically refreshes upon a champion kill so you can feasibly escape from a turret dive without the use of flash by shunpoing onto an enemy or friendly minion or champion. However, this is not the main reason I picked flash in the first place.

The main reason for this spell is not for escape but to finish off a champion and catch them unaware. For example, many times when I play mid, I get the enemy's health down to just enough so that if I can shunpo onto them and use ignite/ultimate, I can finish them off easily. However, most summoners are intuitively aware of shunpo's range and will not get close enough to fall for that trap. In fact, if you try to run toward them, they will just back away.

This is where flash comes in handy and how to use it. Let the enemy push to close to your turret to lessen the chance of them running away. Then, flash forward and shunpo onto them and use your ult and ignite, finish off with bouncing blades as they near the range limit of your ult. Most times, I am able to finish an enemy off using this tactic and catch them unaware. This is because the extra range provided by flash and quick execution essentially gives you the necessary range for you to shunpo onto the enemy after flashing forward.

The only skill necessary is quick execution and predicting when your enemy's life is low enough for you to finish them off. That said, try it sometime!

===Abilities===

: Boucing Blades is your primary farming and harassing ability. Use it whenever you can since its cooldown is pretty low.
: Killer Instincts is good when combined with Bouncing Blades for better harassing OR can be used with shunpo to reduce damage taken. In ganks where people will most likely target you when you shunpo in, this is very useful for staying alive.
: Shunpo is also one of your harassing abilities. It is pretty powerful when using this build, which focuses on AP. It can be used to finish the enemy off especially in situations in which they're trying to escape or to escape as well by shunpo'ing onto any friendly or neutral units.
: Death Lotus is your damage-dealing ultimate. It is best used in team fights at level 16 when you can hit the three closest enemies from you. With this build, you can easily do over 200 damage per dagger for ten daggers assuming no interruptions. In most situations, this is a guaranteed champion death if you combine this with shunpo and bouncing blades. The ultimate can be interrupted by any CC (except Ryze's rune prison) while channeling, so it may be useful to invest in a Banshee's Veil if the other team has a big number of CC'ers. Alternatively, if your team has a Morgana, ask them to put a magic shield on you right before you shunpo in to use your ult.

If this build works for you, post your screenshots in the comments section. (examples below)

===The Long===

===Early Game===

I start off with 3 Health Potions and Boots of Speed. A little bit of health and speed is good at the beginning since Katarina is somewhat of a squishy character and won't survive ganks. It is best to play mid as Katarina since effective farming will allow her to level up quickly and to gain gold at a faster rate for this build. Save the health potion for when you're forced to stay at your turret with low hp. If the enemy is attacking the turret, the easiest way to get them to leave is to shunpo onto them and then using bouncing blades and then running back to the turret.

From levels 1-3 concentrate on last hitting minions using bouncing blades and shunpo. Leveling up and gaining gold is more important than harassing an enemy especially if the enemy has the ability to heal such as Vladimir.

I find it that harassing your enemy generally isn't very effective and slows down your farming until at least level 4. If the enemy is a squishy like Teemo or Annie, you can try harassing although keep in mind that you may receive damage in return since your enemy is almost always ranged at mid. If you do choose to harass, use E -> autoattack -> Q and then quickly running back. The point is to get the enemy's HP down without much damage to yourself. Depending on your opponent's skills, this may be extremely effective or not effective at all. If your opponent really underestimates you, you can sometimes finish them off at the tower by using the same tactic E -> autoattack -> Q and then flashing out of the turret's line of sight.

Generally, it is best to wait until level 6 before really trying to kill your enemy. In this case, use E->R->Ignite->W->Q. Immediately after pressing R, you can press W and Q since this will not disrupt your ult and gives you the region in which bouncing blades will work. As soon as the enemy nears the border of the Q region, click on them to activate bouncing blades. With practice you can usually get a kill this way.

Of course if the enemy has flash, you may want to trick them into using it by shunpoing onto them and then not pressing R but using W->Q instead. If they don't use flash and continue to attack you, you may either run back or continue with ignite and R. Go back to purchase Hextech Revolver once you have 1200 gold. The spell vamp is more useful than the attack damage given by Bilgewater Cutlass and also the Revolver is cheaper. You can jungle around to level up faster and get more gold if you there doesn't seem to be team fights going on. Try to stay in the lane for longer if possible since you'll gain experience and gold. Rush the Hextech Gunblade and finish your Ionian Boots of Lucidity.

Rushing Hextech Gunblade produces good results since you automatically add more damage to your abilities than Rylai's. Also, you can stay in your lane for longer periods without the use of health potions since the spell vamp and life steal help tremendously.

---Strategy----

Upon reaching level 6, you may want to help your teammates gank top and bottom. However, do not leave mid open. I generally either kill the mid champion first or wait until he or she teleports back to base. You don't want your enemy taking free hits on your mid turret while you're waiting aimlessly in a bush for the right time to strike.

---In Some Situations---

If your mid enemy is particularly bad, you may want to buy Mejai's soulstealer after Ionian Boots of Lucidity and possibly Sword of the Occult.

===Mid Game===

After the Hextech Gunblade, go for a Rabadon's Deathcap immediately. Try to get uselessly large rod first if possible.

Now you're ready to gank with a good chance of killing without dying assuming you are not behind in levels compared to the opposing team. This is also where the build deviates depending on the enemy team. You will always want your teammates to initiate if the enemy team has a lot of CCer's (stuns, silences, knock-into-the-air etc.) After waiting for the fight to begin, I would shunpo onto the squishiest character if possible using W->E to also lessen damage taken should they target you. Use your Hextech active ability. By this time, some CCer may have tried to stun you, but since you haven't used your ult yet, proceed by pressing R to begin death lotus. In the event that your ultimate gets interrupted, finish with Q on the squishy and either keep on attacking if you're not targeted and have decent amount of health or get out of there if you are being targeted. Flash may be useful here. Since your abilities are based on cooldown, you may want to linger and rejoin the fray if it seems that your team has the upper hand, but beware if you have low health and do not stay to close to the fight.

===End Game===

Build either rylai's scepter or abyssal scepter next. If you are confident that you can get a few kills and survive or at least get a few kills before dying without the use of rylai's scepter's slow, then you may want to skip building rylai's scepter and prioritize on the magic resistance and extra AP granted by abyssal scepter.

NOTE: Ryze's Rune Prison does not stop your ult!

At this point, many games will have a definite conclusion or it will become very obvious. However, if it doesn't, consider the following items if you didn't purchase mejai's scepter.

Buy an Elixir of Brilliance and use it and then start to build one of the following items.

For cooldown reduction, build a nashor's tooth. This is extremely good for Katarina, who is a cooldown champion. Doing the math, you get 15% cooldown from the boots and 25% from nashor's tooth, which gives you the 40% cooldown reduction maximum! If you are skillful enough at staying alive, you can postpone both rylai's scepter and abyssal scepter and build the cooldown items FIRST. It is possible to stay alive if you aren't targeted by spamming your abilities since hextech gunblade does provide lifesteal and spell vamp.

If you're shutdown all the time and die too much, you may want to shoot for a banshee's veil.

For non-serious matches when you're far ahead, you may consider warmog's armor. This is only a good idea if you have a lot of extra gold, however, and usually, it isn't the case. Also for non-serious matches, if you would rather like to focus the turrets by backdooring, consider purchasing Guinsoo's Rageblade. This may allow you to effectively "backdoor" the enemy base and definitely will allow you to get rid of turrets faster. This item can also be purchased earlier in the game if you wish.

Good luck Summoner!
-1337azn

Hextech Gunblade now becomes a very attractive item for Katarina as both its AD and AP stats are now factored into two of her abilities. Bonus passives include spell vamp and life steal. The item also deals 300 magic damage and slows the enemy champion when activated increasing your chances of killing fleeing champions. A note of interest is that this build heavily focuses on stacking AP since AP factors into all three of of Katarina's damage dealing abilities whereas AD is not factored into Katarina's powerful "Shunpo" ability.

P.S. Support this build by leaving constructive comments and by giving it a positive rating!