If Shadow of Mordor is not running well on your PC, the best thing you can do to start will be to run the "Auto Config" option under the In-GAME Options > Advanced Options > Auto Config. If you continue to experience performance issues after doing this, try the suggestions below:
First make sure that your computer meets the requirements to play the game. If you do not meet the requirements listed (64-bit Operating System, 3 GB+ of Memory, etc.) the game will not run correctly.
Make sure the game is using the correct video card in your system
For systems that have more than one video card (often a dedicated video card for games and an "integrated" card for general use), it is possible that your system is directing Shadow of Mordor to use the wrong card. If you check the Advanced Optioons menu in-game you will see the card that is currently being used at the bottom right of this screen. If this is the incorrect card, you can change this by going to the Video section of the Options menu and changing the "Display Adapter" to your desired video card.
Update your video/sound drivers
Often you can update your video & sound drivers by checking your system manufacturer's website and visiting the driver update page for your system model. You can also download updated drivers directly from your video or sound card manufacturer if you know what type of card it is. AMD and Nvidia also offer "automatic driver" installations if you know you have an AMD or Nvidia card but do not know what the model is.
Use graphics settings that match your system
You can use the Auto Config option in the Advanced Options menu as mentioned above to have the game determine what settings will be best for your computer. If you are using custom video/graphics settings via the Advanced Options menu in-game please note the details below:
You may experience instability if you set graphics to a level too high for your system. In particular, the higher texture settings in Shadow of Mordor required a fairly powerful computer. You can check the Advanced Options menu and highlight the Texture setting to review the video card memory requirements for each Texture Setting. It is not recommended that you select a texture level higher than what is listed for your videocard's memory (visible in the bottom right of the Advances Options screen). Try lowering these settings or using the Auto Config option if you are experiencing problems or are unsure of what settings to use.
Verify Game Cache
If playing Shadow of Mordor through Steam, make sure to verify the integrity of game files. Do so by following the steps found here.
If you have tried the steps above and the game is still not running well for you, please contact WB Games Support.