For all three of them, you must be following the appropriate account. Here is a summary of each contest:
- Starcraft: Tweet how you are the biggest StarCraft 2 fan using the #SC2fan hashtag for a chance to win one of 500 Starcraft 2 beta keys.
- Diablo: Tweet an item name using the #D3unique hashtag to win one of many Diablo 3 prizes.
- Warcraft: Using the #Battlecry hashtag, tweet "For the Horde" when the background of the @warcraft twitter page shows a Horde flag and "For the Alliance" when the background is Alliance. Horde or Alliance prize packages are up for grabs in this sweepstakes.