First thing, know what your specs are, mine for example - AMD R9 380 4GB GDDR5, 14GB RAM, AMD Quad Core A8 5500 3.2 GHz. Now I play in Ultra @ 50-60FPS out in the the wasteland which is more than playable. Seccond step make sure your drivers are up to date

AMD - http://support.amd.com/en-us/download
Nvidia - http://www.nvidia.com/Download/index.aspx?lang=en-us

Make sure you know what your Operating system is that is VERY immportant for you so you know which driver you need to download also know if your OS is 32Bit or 64bit.
You can ignore this all but I highly advise you to get the latest drivers it does make a huge differense. Next for the settings, this game does not look at all different on low settings. Sadly I have no idea how to change these settings in-game but you can edit the settings on the launcher. I reccomend trying your game on medium for your looking for "decent" quality. As I said there is hardly any difference between "high" and "low" graphics settings. If this does not help contact me by adding me on steam or via email, my email is itstoxiik@gmail.com or battleman50@gmail.com.

System Requirements
MINIMUM:
OS: Windows 7/8/10 (64-bit OS required)
Processor: Intel Core i5-2300 2.8 GHz/AMD Phenom II X4 945 3.0 GHz or equivalent
Memory: 8 GB RAM
Graphics: NVIDIA GTX 550 Ti 2GB/AMD Radeon HD 7870 2GB or equivalent
Storage: 30 GB available space


RECOMMENDED:
OS: Windows 7/8/10 (64-bit OS required)
Processor: Intel Core i7 4790 3.6 GHz/AMD FX-9590 4.7 GHz or equivalent
Memory: 8 GB RAM
Graphics: NVIDIA GTX 780 3GB/AMD Radeon R9 290X 4GB or equivalent
Storage: 30 GB available space

I hope this helped some of you guys! Good luck :D