Crusader Kings II: Ruler Design Minimum System Requirements:
PC:
OS: XP/Vista/Windows 7
Processor: Intel® Pentium® IV 2.4 GHz or AMD 3500
Memory: 2 GB RAM
Hard Disk Space: 2 GB
Video Card: NVIDIA® GeForce 8800 or ATI Radeon® X1900, 512mb graphics memory required.
DirectX®: 9.0c
Sound: Direct X-compatible sound card
Additional: 3-button mouse and keyboard

Mac:
OS: Mac OS X 10.6.8 or later
Processor: Intel Core Duo Processor (2GHz or better)
Memory: 2 GB RAM
Hard Disk Space: 2 GB
Video Card: ATI Radeon HD 6750 / NVIDIA GeForce 320 / NVIDIA GeForce
9600 or higher

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.

Activation on Steam

1)      Download & install the Steam client on your computer from   here.

2)      Open the Steam client, register and login. Then, locate the Games tab on the top menu. Click that and select “Activate a Product on Steam..”

       

3)      Enter your code that is showed on the orders page of eTail. Market and and follow the steps showed to activate your game.

       

4)      The game can be monitored now and you can see it on the "Library" section on Steam. You can download and install the game now.

5)      If you need more information and support, you can click here: https://help.steampowered.com/en/wizard/HelpWithSteam