Please keep in mind while reading this guide that this is not what you HAVE TO DO in order to succeed with Orianna, this is just a guideline to help you get started.
Please, after trying the build out, leave a comment and tell me what you think of it.
In the current meta (tanky dps top, AP carry mid, jungler, support + AD carry bot) Orianna serves the role of an AP Carry. So don't pick Orianna if you already have Malzahar and Fiddlesticks on your team.

My runes are pretty standard caster runes, Greater Mark of Magic Penetration to increase overall damage, especially when combined with Magic Penetration boots.
Greater Seal of Armor to increase early game survivability against physical damage harass such as Caitlyn, Ashe etc. These could be swapped for mana regen runes, it's a matter of personal preference. If you like harassing much I'd recommend mana regen runes, since her W is quite mana heavy.
Greater Glyph of Scaling Ability Power To help out with more ability power throughout the game.
Greater Quintessence of Ability Power to increase early game damage. These could probably be swapped for movespeed quints, but I haven't tried it out yet.

My masteries are 9/0/21, 9 in offense for the 15% magic penetration, 21 in utility for increased movespeed, lower SS (summoner spells) cooldown, more CDR and Mana regeneration.

I choose to run and on Orianna.
Flash is probably the BEST summoner spell in the game as of right now.
Overextended and you spot their jungles coming for you from behind? Flash away. Someone running away from you and you barely can't reach them? Flash to him/her.
I run Ignite because I often find myself (especially early game) lacking that tiny bit of damage I need to kill them, late game it shuts down healing Maximum Dosage etc.

Other viable spells for Orianna:

• Ghost You want to be more offensive? You need more than one escape ability? Ghost is the spell for you. (Also great for chasing) Replaces flash or ignite.
• Teleport Teleporting to a ward for a gank is always fun, Teleporting to huge uncontested minion waves for tons of gold, saving a tower, quick-shopping early game, etc etc. Replaces ignite.
• Clairvoyance If your team is lacking a support character to take this you can pick it up. (protip: every team benefits from a champion carrying clairvoyance.) Replaces ignite.

Spells viable, but not recommended for Orianna:

• Clarity You should have blue buff everytime it's up, there's no need for clarity. This spell becomes even worse late game. Replaces ignite.
• Exhaust Possibly useful, if you have none on your team you could use this. IMO Ignite > Exhaust. Replaces ignite.
• Cleanse Highly underrated summoner. But if you get stunned, slowed or CC'd in any other way you need to improve your positioning rather than just cleansing it. Replaces ignite.

You are not jungling.
This spell is pretty much useless.
Instead of dying, use an escape ability. The only chars I can see this working on are Pantheon and Twisted Fate.
Leave this for tanks.

Kind of a meh passive for Orianna. Helps with last hitting once you get some levels and AP.

The spell we max first, use to harass, farm, zone and set our other skills up. Also does quite some damage.

A powerful damage, chase, escape, harass and farming tool. Costs too much mana to max first, therefore it's maxed second.

A powerful shield late game, plus the passive bonus is great. (You must carry the ball to get the passive bonus.) We get one point in this at level 1 and max it last.

Many people seem to think this is a bad ultimate, however I think it's a pretty good one.
It does huge damage in teamfights and you want to hit as many people as you can with it. Can also be used when ganking to shoot them back towards you.

My skill order is EQWQWRQQWQRWWEEREE.
When in doubt;
> > >

and OR OR and x2. (You can also buy Boots if expecting an opponent with heavy harass.)

If you bought Sapphire Crystal rush Catalyst the Protector ASAP! I can't stress that enough, it will make you stay in lane for such a long time. Later in the game you upgrade it to or you upgrade it to after your boots.

I choose to start with Regrowth Pendant 99% of the time.
This is what you want first trip back. (When getting 2315 gold you push the lane HARD and then recall. Pushing the lane will ge you a few lasthits more aswell as forcing your opponent under his tower, preventing him from a few last hits and making sure he doesn't destroy your tower.philosopher's stone , , and Health Potion if you need them.
Philosopher's stone , ,
I get these item's 99% of the time. philosopher's stone for the gold per 10 and lane sustain, Sorcerer's Shoes for the movespeed and magic penetration. Rabadon's Deathcap is the best ability power item in the game, hands down.

Other viable boot options for Orianna:
I get these if I'm facing a team with lots of hard CC and magic damage. I personally don't think additional CDR is required, but if you have a greedy jungler who wants blue you might choose these instead. I guess these can be used if you like roaming around the map alot. I don't like them so much.

How can these items be useful? / When do I buy these items?

Rod of Ages should be bought if you bought Sapphire Crystal in the start.
Archangel's Staff If you have mana problems with Orianna try buying Meki Pendant in the beginning and buying an early .
Morello's Evil Tome I'm not really a fan of this item on Orianna, but it's a cheap way of getting stats we need.
Mejai's Soulstealer If you can keep up the stacks on this item it's amazing, 200 AP and CDR for 1235 gold? Only buy it if you are 100% sure it will pay for itself.
Abyssal Mask Enemy mages looking scary? This will make you kill them and resist their damage. Solid allround item.
Void Staff 40% Magic penetration for killing those pesky tanky chars.
Doran's Ring If early game is going bad you can always pick up another one of these.

Zhonya's Hourglass More AP and a great active to shield you from all damage for 2 seconds. Buy this is facing lots of AD.
Banshee's Veil A cool passive while making you more tanky. This passive can be wasted if they have a Volley spamming , so be careful.
Guardian Angel Personal favorite, but your team needs to be coordinated if you are going to use it, and not just leaving you behind when you are reviving.
Abyssal Mask Listed both here and under offensive items. A great item to have. I usually get this instead of if I'm in solo-queue.

If high HP, low resistance targets are bothering you you should get this item. With a few 100 AP this thing hits like a truck on Vladimir, Gragas, Cho'Gath (if he's not building tanky).

Buy this if Warwick and/or Malzahar are troubling you, and laugh at them.

Early game you want to figure out who you are going to be laning against, and choose what to buy considering your opponent. Protect blue buff and leash it for your jungler (unless he's following a different route.
The very first few levels you should focus on last hitting exclusively and farming up as much gold as you can.
When you reach level 4-5 you should try harassing your enemy, Command: Attack to send your ball on top of him and if it hits and he's still in range pop your Command: Dissonance and top it off with an auto attack. This combo should take a pretty significant chunk of the enemy's HP, so when you get to level 6 you can hopefully get first blood, or atleast a normal kill or making him use .
If you happen to get wrecked by some dude and you are getting zoned out you need to rely on a gank from your jungler, but be sure to tell him you need one!
If he decides to dive you under your tower you'll want to knock him into the turret and slowing him with your W, then shielding yourself. If done correctly, he/she should die, while you survive. Or you can atleast take him with you to the grave.

You want to farm. ALOT. Try to last hit every minion in every creepwave that comes.
Once you can afford your first 3 items you want to back immediately, if you don't have your jungler setting up a gank, or if your lane is pushed to your tower.
If you have to recall earlier you should buy atleast philosopher's stone and a and a pair of .
If you happen to not be able to buy all of these; philosopher's stone > all. Always get this. Always. The gold per 10 is too good to pass up.

Now, when you buy your Needlessly Large Rod you will see a huge increase in your damage, and you'll be able to clear the caster minions with a simple Q>W combo.
Try to zone your enemy out with your ball, and punish him if he tries to move up and kill any creeps.

Early game ends when you're getting close to having your core done, and usually a few of the tier 1 towers are down then. A dragon may also have been taken by either team.

Mid game is where Orianna shines, you have your core items and you are doing tons of damage.
More people are MIA ganking, dragon is taken everytime it's up. (MAKE SURE YOUR BOT LANE WARDS DRAGON ALL THE TIME SO THE OTHER TEAM DOESN'T TAKE IT!((caps used for emphasis)))
It's now you want to have blue buff all the time.
Teamfights are occurring more often, and you should be participating in every one.
If you have won your lane (which you should!) go gank bot or top.

Orianna can also check dragon or baron from the cliff behind them using her Q, which provides vision.

Depending on how the early game was for your team, build your next item accordingly. Your team is a few kills ahead? Grab Void Staff to counter the other teams new shiny magic resist items.
Your team is a few kills behind? Grab for the extra tankyness and the passive.
Other team has a 3/0 Master Yi or a Tryndamere? will work.

Don't walk around alone, it will get you killed.

Teamfights are one of the most important aspects of the game, and every teamfight is possibly game-changing. You won the teamfight? Push and take down an inhibitor, take baron, go into their base and /dance, do whatever you want. The other team is all dead.

When a teamfight is about to begin, Command: Protect your initiator and try to catch as many as you can with Command: Shockwave and Command: Dissonance.
Use your Command: Attack on their carries and try to kill everyone you can, while avoiding getting killed yourself.

Your ultimate, Command: Shockwave can be used to interrupt certain abilities, such as ' Crowstorm (you need to use your ultimate when he's channeling it).

If you, or anyone in your team is getting focused place your on him/her and use your to kite whoever is chasing.
Your is like a place-able ghost/exhaust for anyone running through it, it's one of the best escape abilities in the game.

Late game Orianna sadly becomes less powerful than you could expect but do not fear! Games usually don't last this long, but if they do you should still be prepared for it.

I wanted to make a little chapter on warding, not enough for a whole chapter in the guide but a little more information.

There are 2 types of wards, sight ward and Vision Ward.
sight ward costs 75 gold and lasts for 3 minutes.
Vision Ward costs 125 gold and lasts for 3 minutes.
They both provide the same sight range.
Now, why would you buy a Vision Ward instead of a sight ward?
Because Vision Ward gives TRUE sight (meaning you can see invisible units in the ward's range).
You'll (almost) always want to place a Vision Ward where you know the enemy has a ward, provided you want vision over that area.
Example:
Team A has placed a sight ward for 75 gold at location X. (Location X happens to be baron)
Team B places a Vision Ward for 125 gold at location X. They see the ward team A placed and destroy it.
125 - 75 = 50.
You set back the other team by (at most) 75 gold, and you now have vision over that area for the next 3 minutes.
A green ward (sight ward) deploys it's gold worth every second the wards duration ticks down; a green ward placed 5 seconds ago is more worth than a green ward placed 1 minute ago.
But I still find it useful to kill enemy wards in a high traffic area, such as Baron Nashor's area.
If you know an enemy placed a ward somewhere where you want to have a ward it's more beneficial to place a pink ward than a green ward there.

Now, back to the 'late game' section.

By now, everyone is finishing the last items on their build, many towers are down, and baron and dragon has been taken.
By late game you should be even more careful than mid game, because if you get caught alone chances are even more slim you'll get out alive.

Orianna is a great split pusher due to her ability to wipe out creep waves fast ( > )
Split pushing is when you push a lane yourself and your team pushes another lane, forcing enemies to decide who to engage.
If you run you can pull off a cool trick here, let's say you are pushing top lane and your team is pushing bot, and 1 person from the other team comes to protect their tower. Your team is 4v4 down bot, and then you Teleport to the bot lane and your team wins an easy 5v4.
Make sure you are able to get out alive if their entire team shows up, you might want to ward possible areas in the jungle so you can see when they're coming for you.

Orianna is a very fun champion to play, she may seem easy to play but even the easiest *cough* Tryndamere champion is hard to master.
I hope you all succeeded using this guide and I'd love any feedback you guys might have.
This guide will be updated regularly whenever I get the chance.

Good luck to you all


Sincerely, P.

CHANGELOG:
29/7 - 2011: UPLOADED GUIDE TO MOBAFIRE