This is a Orianna build for middle lane, but it works for duel lane too. She has probably the best early and mid game harass out there. Why pick this one over the others? There isn't a really good build that is highly rated for her yet. Well until now? :P Give it a shot and let me know if you like.

Early game mana regen is key, with some hp pots to help you through those rough times at the start. Get pen boots for higher dps late game, unless you need something else like magic resist because of early ganks or something that put you out of minion advantage. Athene’s Unholy Grail Follow up with Rabadon's for huge amount of AP and cd reduction. Then archangel staff which has her name all over it. Then from that point it's do whatever feels right. The build above is what I often times end up doing.

Short and sweet. Attack = Good. Dissonance = Good. Attack + Dissonance = Awesome! The way I have my skills set up take advantage of this.

Orianna likes to use mana. Clarity is good with her so that you can spam your ball all day long. When clarity is on CD, just B back to base and Teleport in with full mana again. Also both are good to help your teammates late game.

A team with a good Orianna on it can be a game changer I have noticed. Try this guide out. Remember to vote it up if you like it! Thanks!