minimal:
reqprocessor: Intel Core 2 Duo E6600 @ 2.4 Ghz or AMD Athlon 64 X2 5000+ @2.6 Ghz
reqgraphics: nVidia Geforce GTX 250 / ATi Radeon HD 4870 with 512MB or integrated Intel HD 4000 with 3GB system ram.
reqmemory: 3 GB RAM
reqdiskspace: 10 GB available space
reqsystem: SteamOS, Ubuntu 14.10 with proprietary drivers

recommended:
reqprocessor: Intel Core 2 Quad Q6600 @ 2.4 Ghz or AMD Phenom X4 9900 @ 2.6 Ghz
reqgraphics: nVidia Geforce 460 1GB or AMD Radeon HD 6850 1GB
reqmemory: 4 GB RAM
reqother: A 1920x1080 screen resolution.