Update! StarCraft has been ported to ARM:

* [Reddit discussion](http://www.reddit.com/r/ReverseEngineering/comments/201a4a/starcraft_reverse_engineered_to_run_on_arm/)
* [Hacker News discussion](https://news.ycombinator.com/item?id=7372414)
* [Geek.com article](http://www.geek.com/games/starcraft-has-been-reverse-engineered-to-run-on-arm-1587277/)
* Download: http://repo.openpandora.org/?page=detail&app=package.starcraft

So, I've unaccepted the best answer, and the question stands as is.

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I often meet with friends and if not more than one computer is available, we take take turns playing games. Instead, would we be able to use a Raspberry Pi with an additional monitor/keyboard/mouse to play against each other, or play on Battle.net together? If so, how would I configure this?

Minimum System Requirements from (http://gamesystemrequirements.com/):	

- CPU: Pentium 90 MHz or higher	
- RAM: 16 MB RAM	
- VGA: DirectX-Compatible SVGA Video Card (DirectX-compatible)	
- OS: Windows 95/98/NT	
- HDD: 80 MB	
- Sound: DirectX-compatible sound card for audio	
- Network: Multiplayer System Requirements:
- 14.4Kbps Modem or Null Modem Cable
- IPX network or Battle.net (requires low-latency connection with support for 32-bit applications)	
- Recommended peripherals:	Microsoft-Compatible Keyboard, Mouse

Keep in mind that the game can be installed from a USB flash drive or downloaded.