11/1/11 - created the guide

11/1/11 (b) - flipped around some phrasing in the Items Chapter and altered the first Item build to reflect the change.

12/18/11 - updated the Masteries, threw in some more commentary about jungling. Going to modify the Items List (haven't yet) now that I've had the time to actually play this build alot more making it less theoretical and more practical. Still reletively minor changes.

People that have never played Orianna tend to be put off by her difficulty level. It's because of this and the lack of a high quality build that I wanted to do a guide that not only shows what to build but the reasons behind those item selections. I wanted to attempt to best explain how to use Orianna so that people that want to try her can do so and do so effectively.

Please read the whole thing before you go and vote. Even better try out the builds and let me know how it worked out for you. I love to get helpful criticism and feedback so I know I'm not just crazy for spending hours writing this guide.

In order to understand Orianna, one needs good Map Awareness; keeping tabs on who is doing what, especially yourself. The main thing that can be a challenge is keeping track of your ball in team fights and hairy situations. Timing is key and if you find yourself needing to flee and you don't have your ball, you can be seriously screwed.

All her abilities are through her ball. Because of this you not only have the cooldown to look after but transit times. You can't activate another ability while the ball is in transit. So spamming 'W' won't do you much good until the ball stops moving. The shorter the transit, the quicker you can cast your next ability. I still find myself missing with Command: Shockwave because of the transit time but luckily when you have high Cdr, (cooldown reduction), the recharge rate isn't too terrible and you'll be slinging it out again before you know it.

Orianna is mana hungry early through mid game. Because of this you need to get your mana stores and regen rate up as soon as possible to keep her going in battle. Until you do you'll find yourself oom (out of mana) and recalling often or buying mana potions to compensate. Even still, it's good to throttle your ability usage. Getting a blue buff mid to late game helps out a lot but isn't a necessity.

Basic attack combo:
Her ball causes straight damage no matter how many units it passes through. Usually when the minions meet, I throw it to (or a little behind) the caster line and hit Attack: Dissonance to take them out. I'll bring the ball back with Command: Protect to do a little more damage to the melee line again. This is the basic attack set up for her as you'll use it countless times to get yourself last hits with the ball. Remember last hitting is essential as it pays the bills. However if you're in a team, you'll likely want them to get the last hit instead, but don't go out of your way if you're clearing a couple backed up waves of minions.

Pros:
Support
Plan on switching to the support role any time you are in a team fight. While you can harass with your ball, you can't going to be the main damage dealer...by a long shot, especially early game. Focus on keeping the ball on your teammate giving them a bit of protection if needed and ready to hit Command: Dissonance if he's not doing well. This is his exit strategy now and if they are up against another close fighter, it'll be extra damage you're dealing as well as a speed modifier.

Resistance
If you find yourself in mid or just solo, play conservatively. Focus on minions and gently harass the enemy champ(s) to keep them at bay. While she can't push the line so much in mid, she can definitely slow the progress up to the turret. Once the turret comes in play the enemy Push is all but nullified while the turret takes minimal damage. The enemy will watch the ball and try to avoid it if they can because they won't know when you'll move the ball or if you have enough for a Command: Dissonance cast or not, or when you will spring it. After you gain your ultimate, if you can manage a setup with the ball without it looking obvious, you can place it just within range of your tower and pull the enemy within range and throw down a Dissonance to keep them there a little bit longer. Most players are savvy to that strategy, but it works on occasion particularly when they are pushing a little too aggressively.

Defense:
A fully ranked Command: Dissonance will all but take out minions even without much for AP boosts. This is a good reason to play defense in protecting lanes when they are being pushed. She can take out the whole group rapidly and with little effort. Any team worth anything that has an Orianna should expect her to clear lanes if it's needed because there are few others that can do it as effectively.

Harassment
Lucky you that Orianna is essentially two characters when it comes to fighting style. While you can do some damage with your Clockwork Windup, you can be move your ball around catching the enemy from the side if they fail to keep an eye on the ball. This is especially useful if you have it sitting in the bushes and decide to throw it out and across the enemy line.
Her ball has the nice ability to fly over trees. Unfortunately you don't get to practice that often as her range is only just enough to clear said trees and a little bit more. Still if they are hugging the treeline while fighting your team mate, it can still be possible to fling it over and hit a Command: Dissonance to slow them down of if luck has it, kill them outright.

Cons:
Map Awareness
I suppose its with all champs, but with her in particular, if you can't good at map awareness, even just what on your main screen, you're going to do poorly with her. As said before it's like you're controlling two characters. It takes a lot of awareness to know both what and where your character is as well as placing the next ability where it needs to be.

Timing
You have the cooldown timing and transit timing to worry about and with Command: Shockwave, you have the third variable of the ability's slight charge time.

Slow Movement
Outside of using Command: Dissonance, you're rather slow moving. This makes you susceptible to ganks if you just used Dissonance offensively or are unable to get your ball back and running out of range may be too long of a wait.

Slow Attack Speed
Because she is one of the slowest auto attackers she must rely heavily on her abilities to cause notable damage. She can finish off an enemy with her abilities, but she can't really chase down enemies without some outside help.

Squishy
Especially early game, she is rather squishy. She tends to be targeted first throughout the game so you can't over extend yourself and never turret dive unless you managed to grab enough HP Items. Even then it isn't well advised.

Clockwork Windup
a nice passive that deals more damage the more you hit the same unit. On the down side your attack speed it quite slow. While I've attempted to make a workable AD setup with Orianna to try and benefit from this ability, I've yet to find any conclusive build that doesn't leave me lacking until late game at best. That said, most people tend to scream at you should you try such a thing unless you know for certain that your setup will work. 9 out of 10 times it likely won't so I advise against it and just rely more on your Ball for the heavy hitting. Its nice to have to last hit minions, but that's about it.

Command: Attack
Your main hitter, mostly because it gets the ball moving (terrible pun I know). Grab a point on this right away, however this isn't the ability you want to focus on early game. As said before, the ball will do static damage regardless of how many units it passes through. Because of transit times, you need to always aim ahead when in a Champ fight. Even so, you'll find yourself falling short if you have to move to get into range as they will probably already pulling back from you. This is why it is more important to focus on the minions Early game. It's worth more in terms of mana usage.

Command: Dissonance
The powerhouse of your abilities. This will keep you alive or go in for the kill. It'll clear minion waves like nothing. It's not to be underestimated and can easily turn the tide in team battles. It throws out a movement speed modifier allowing allies to go faster and enemies to go slower. When you're being chased in the jungle, this is what gives you your break away as they will be hard pressed to avoid it. This should be maxed by level 9 no matter what.

Command: Protect
This will give you or an ally a temporary shield. It'll also do some damage if it passes through enemies, though not nearly as much as Command: Attack. Use this to recall your ball or to boost your teammates survivability especially when used with Command: Dissonance. Unless you're having a difficult game, I suggest leaving this to be the last ability to max, but grab 1 point in it early on.

Command: Shockwave
It has a brief charge up time that can mess with your own timing if you are trying to quick grab a player. It's the hardest to pull off unless the enemy is bunched up and moving slower. This is probably where you'll notice transit times being a key factor in your usage because you'll get frustrated from missing because the ball hadn't settled AND the short charge up allowed the enemy to only just miss the edge of the effect. Still when you pull it off, it'll do almost as much damage as your Command: Dissonance and provide a brief stun. This ability throws the enemy a set distance in the direction of the ball. This means if you catch them at the edge it'll make them move just as far as if they were in the midst of the effect and NOT to the other edge of the effect. The set distance is approx. the radius of the effect's range. So the enemy caught at the edge of the effect will be somewhere right next to the ball. This is good because you can usually throw your Dissonance down and grab them with a slow, though not always.

Greater Mark of Magic Penetration will grant you your Magic Penetration that will be helpful cutting through your enemy. Any other Mark isn't really of optimal value.
I usually go for Greater Seal of Replenishment over Greater Seal of Scaling Mana Regeneration because by late game your mana problems should be over, but the early game regen can really help to keep you on the field longer.
For Glyphs, I go with Greater Glyph of Ability Power for the added ability power. If you want more Magic Penetration, go with Greater Glyph of Magic Penetration or if you want Magic Resistance do Great Glyph of Warding. You could go with Greater Glyph of Scaling Magic Resist as well, but your early game is when you're weakest and unable to flee effectively.
With your Quintessences, you can get any that boost what you already have. I choose Greater Quintessence of Magic Penetration for greater Magic Penetration, but any would be good depending on how you feel your games are going.

I go 9/0/21 grabbing the magic penetration boost in Offense and filling out Utility. Grabbing Insight if I don't like the mana issues early to mid game or if I can live with it, I'll take Mystic Vision to boost Clairvoyance and help with keeping my team informed a little better. You can grab Spacial Accuracy if you want, but the benefits are marginal at best and that point can be used elsewhere more effectively.

For my Summoner Spells I always take Teleport since that works great for defense and popping in near an ally to help them with a kill or getting them out of harms way. The other spell I usually take is Clarity though I've moved to Clairvoyance recently and changed my playing style to accommodate the lack of a mana boost when I need it. It's worked out well and my teammates seem appreciative with the added intel and keeping them from getting ganked so often.

Another good spell would be Fortify as it doubles the firing rate of your turrets. Coupled with Command: Shockwave, your turret may be able to get an extra shot or 2 off killing the champ.

This is in no way a solid go to on what to get. Each game is different and you'll come up against varied challenges. However, I'll explain my own personal decisions as best as I'm able. If it gets confusing I’ll have the builds summarized at the end.

Early Game: (standard start up and planning your game style)
There are various routes to go here. You can start with the recommended Doran's Ring, but that leaves you without a health or mana potion to carry. I tend to grab the Meki Pendant instead as is will still grant me a good early mana regen and a either 2 health pots or 1 Health and 1 Mana Pot. I'll aim for a Philosopher's Stone as my next purchase. Don't be afraid to build up to it if you have to. This will grant me good mana regen early on as well as a little gold growth, though that isn't the main reason for getting this. Next you'll want your Boots. If you're having trouble getting away from the enemy you can grab these before or in the middle of building your Philosopher's Stone. You'll want to finish up with completing your Ionian Boots of Lucidity as this will grant you 15% Cdr.

Mid Game: (Mana stabilizing and AP or defences)
If you grab a Fiendish Codex next, build it into Morello's Evil Tome and you'll want to grab Eleisa's Miracle granting you a good health regen and tenacity. This will give you a total 35% Cdr. and you shouldn't build any more items for Cdr.
If you build your codex into Deathfire Grasp, you'll be at 30% cooldown but you'll be able to use the Active Ability to nuke a Champ.

If you lean more for the support side, I suggest grabbing Soul Shroud and finish your Philosopher's Stone into Shurelya's Battlesong which will grant you your max of 40% Cdr and give you an Active Ability that boosts your (and nearby allies') movement speed by 40%. Used with Command: Dissonance, you'll have no problem running away or closing the gap with a teammate. This setup will also make you a little less squishy and even more mana regen.

Late Game: (rounding out your AP and damage potential)
For this guide, late game comes early as you'll be tricking out Orianna for maximum effectiveness.

With your mana troubles mostly fixed now with either build above, it's time to really focus on your AP and Magic Penetration. The recommended item list did a pretty good job with a few of the items. Rylai's Crystal Scepter is one of them. It makes the enemy slow with your ability usage which is great in assisting in team fights. Definitely a must if you're going to be mainly support.

If I didn't grab Rylai's Crystal Scepter, and I have Soul Shroud, I'd want to hit up Archangel's Staff for the AP boost and Moonflair Spellblade for the tenacity. I'd round it out with another Archangel's Staff granting stacked AP effects (6% instead of 3%, making the AP bonus 234 and bringing the total up to 382). In lieu of a second Archangel's Staff, you can throw in Manamune gaining free mana with both basic attacks and abilities (2000 bonus to the pool at max). You won't notice yourself doing basic attacks in game so much, but you'll be doing enough to get that extra 1000 mana quick enough. You can hold off with Moonflair Spellblade until you get the other two. If you aren't having troubles with being stunned or snared, then forgo Moonflair Spellblade and grab the Void Staff or a Rabadon's Deathcap.

If you did grab Rylai's Crystal Scepter, then grab the Void Staff next. Because you'll probably be in the thick of things slowing down enemies and what not, grabbing Guardian Angel may not be a bad idea. If you're doing good, then perhaps go with Abyssal Mask or Aegis of the Legion. If you with fellow mages, do Will of the Ancients instead of Aegis for that spell vamp aura, they won't be disappointed.

Build 1:
Meki Pendant + Pots
Philosopher's Stone
Ionian Boots of Lucidity
Morello's Evil Tome or Deathfire Grasp
Eleisa's Miracle
Rylai's Crystal Scepter
Void Staff
Abyssal Mask


Build 2:
Meki Pendant + Pots
Philosopher's Stone
Ionian Boots of Lucidity
Soul Shroud
Shurelya's Battlesong
Archangel's Staff
Manamune
Moonflair Spellblade or Void Staff or Rabadon's Deathcap

This is by no means the only things she can grab and again each game is different, requiring different items to suit the situation.

Don't jungle at all, but once you are at level 9 or so, you should be able to grab the blue buff without it hurting too much. I will admit that I tried solo jungling with her...in an AI only custom game. It's possible to manage jungling, but you're better off to be in a lane as you fall way behind due to your squishiness. the gold you get is put into pots. If you're undetered by my advisements and you really really want to jungle with her, grab an Amplifying Tome first and as many Health Pots as you can. I suggest getting the bonus gold mastery in Utility to accomplish this from the start. Then set yourself up to build the Frozen Heart next. Don't hit the Blue Buff right away without a leash.

As for Backdooring, I advise against is as too often you'll get ganked if you go to far. Even with her Command: Dissonance, she can be stunned enough to quickly take her down. If you do try this, I would only go so far as to push a minion hoard up and let them take on the turret and subsequent champs alone. Her auto attack is generally too weak to bother blasting turrets and it's not worth being killed over for that little extra damage you'd be causing. Smart way to push lanes in mid to late game, is to get your minions up on one lane then Teleport across the map to push the other forward. If the enemy saw you in the first lane they'll likely divert to take on the minions while you just flipped safely to another lane.

Playing Orianna is a lot of fun and drives you to become a real good team player. Stay with your teammates when you can and help them out. Play defense more if the game is going the wrong direction.