Orcs are the powerhouses of War2. They accomplish nearly everything through brute strength and numbers. But even the Orcs have their strategies, and here they are.
The soundest strategy (with either race, actually), as well as the most hated, is the grunt rush. If you can eliminate your opponent before the game really get under way, you have saved yourself a lot of trouble. You won't have to deal with mages or enemy bloodlust. For the three of you out there who haven't heard of a grunt rush, it is the quick training of multiple grunts, then rushing your enemy's town in hopes of oliberating him before he has had a chance to build anything important. Speed is of the utmost importance. While it is a strategically sound tactic, many people will hurl insults your way after a grunt rush. Neither of us particularly like the grunt rush, and we never use it, so we won't be putting a grunt rush page up. But Guruchild's Rush Page is a good one if you like that kind of tactic. Just don't say we didn't warn you.
The attrition method is not nearly as important to orcs as it is to humans. There are basically two (effective) tactics for orcs. They are:
1. Grunt Rush
2. Get Bloodlust fast, then Ogre Rush
So the mid game strategy is not very detailed. Just follow the Build Order and you'll be fine. If the game makes it this far, your concern should be shifted to getting bloodlust.
What can we say? As soon as those black spires appear on what used to be a lovely Stronghold, build an Altar of Storms. Have five or six guys repair it, and hit that Upgrade Ogres to Mages button when it's done. Wait a few minutes for the big dumb guys to study up on their magiks, then research Bloodlust. This should not take more than 30 seconds or so, Bloodlust researches pretty fast. Then build 9 or 10 barracks, pump out the ogres, and pummel your opponent until he cries for mercy. You can use DKs if you want, but they're so expensive, have so few good spells, and are so easily killed (especially against humans).