Minimum
OS: Windows® 7 (32/64-bit)/Vista/XP
Processor: 1.7 GHz Processor (Requires support for SSE2)
Memory: 512MB RAM
DirectX: DirectX® 8.1
Hard Drive: 1 GB available space
Sound Card: DirectX Compatible
Network: Broadband Internet connection
Recommended
OS: Windows® 7 (32/64-bit)/Vista/XP
Processor:Pentium 4 processor (3.0GHz, or better) (Requires support for SSE2)
Memory: 1GB RAM
DirectX: DirectX® 9
Minimum
OS: OS X Mountain Lion 10.8
Processor: 1.7 GHz Processor
Memory: 1GB RAM
Graphics: NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher
Hard Drive: 1 GB available space
Network: Broadband Internet connection
Minimum
OS: Ubuntu 12.04, SteamOS
Processor: 1.7 GHz Processor
Memory: 1GB RAM
Graphic Card: NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher
Hard Drive: 1 GB available space
Sound Card: OpenAL Compatible Sound Card
Network: Broadband Internet connection