Windows
OS:Windows XP / Vista / 7
Processor: Intel® Pentium® IV 2.4 GHz or AMD 3500+
Memory:2 GB RAM
Graphics:NVIDIA® GeForce 8800 or ATI Radeon® X1900 video card, 512Mb graphics memory required
DirectX®:9.0
Hard Drive:2 GB HD space
Sound:DirectX compatible sound card
Additional:3-button mouse, keyboard, speakers, Internet connection for multiplayer, resolution at least 1024 x 768, Requires the base game Crusader Kings II
Mac
OS:Mac OS X 10.6.8 or later
Processor:Intel Core Duo Processor (2GHz or better)
Memory:2 GB RAM
Graphics:ATI Radeon HD 6750 / NVIDIA GeForce 320 / NVIDIA GeForce 9600 or higher
Hard Drive:2 GB HD space
Additional:3-button mouse, keyboard, speakers, Internet connection for multiplayer, resolution at least 1024 x 768, Requires the base game Crusader Kings II
Linux
OS: Ubuntu 12.04 LTS
Processor: IntelR PentiumR IV 2.4 GHz or AMD 3500+
Memory: 2 GB
Hard disk space: 2 Gb
Video Card: ATI Radeon HD 6750 / NVIDIA GeForce 320 / NVIDIA GeForce > 9600 or higher, 1024MB graphics memory required.