A quick, dirty guide on how to completely devastate as Orianna in Dominion. Why attack speed? The general uselessness of casters in Dominion and Orianna's recent nerfs make her really sub-par for just about everything.... unless you use this build. I'm pretty much assuming you already know how to play Orianna and just need a good build for Dominion.

Not really much to say, AP/level glyphs are probably better in Dominion... Anything/level for that matter. I just used what I use in Summoner's Rift.

I find defensive and support trees to be just about completely worthless in Dominion unless you're a full tank who needs the extra survivability or a point capper who wants the extra movement speed.

A fairly obvious hybrid AP/AS build. A good alternative build would probably include a deathcap at/near the end and/or a survivability item like Zhonya's hourglass.

I start with all three skills because they are useful. Max out shield first because it's the most helpful, your damage will be coming from auto-attacks. W is second for the extra damage and slow. Q is last because it is generally useless.

Summoner spells don't matter much, I tend not to get much use out of any except for ghost in Dominion. I'm sure flash/ghost and ignite/ghost might be better than garrison, try what works for you.

Well, if you don't already know then there isn't much I can teach you here. The best general strategy for Dominion is to cap three points and hold them. You will pretty much always want to be standing on a point defending it if you have three points because if the other team doesn't try to cap one they will eventually lose. The best place for you to fight is on the points because they will do damage to enemies attacking you on them. Farm some minions if not much is going on near you.

If the other team has you 3-capped you should attack a point, it is best to go for one with your team, but sometimes they are worthless or too far away and you will need to find one to attack alone.

Orianna isn't the easiest character in the game to master because her spells revolve around the ball. Since you will be playing her as a ranged DPS, you will want to keep your enemies out of melee range. Use your Q to get in position to slow your enemies with your W and your ultimate. You will want to auto-attack whenever it is safe to do so. If they chase you, kite them. This means fight while running, hit them with your Q-W combo to slow them and try to hit them when you shield with E. When they are low enough or when you are safe at a tower, auto-attack to finish. A lot of enemies you don't even have to kite because you'll kill them faster anyhow.