System requirements?

I’m very new to Linux and am interested in isolation software. I just want to know the system requirements for running only one LXC. I only intend to run two instances of a video game (optimized for single to dual core), one on the host and the 2nd in the container.
Disregarding the video card, can a quad core processor suffice or do I need it multithreaded? Also 8 gigs of RAM should be fine right?

The game that you are describing should be fine with your quad-core, 8GB RAM computer.
I suppose that the game needs up to 3GB RAM (3GB + 3GB + 2GB for the host).

You mention “LXC” though I suppose you mean “LXD” in this case.
In a nutshell, “LXD” is built over “LXC” and has a container manager that makes it much user-friendly.
For more on the distinction, see Comparing LXD vs. LXC

There is a tutorial on LXD and running GUI apps with hardware acceleration for the graphics.
The way this works, is that the app running in the LXD container has full access to the desktop X11 server.
See the relevant tutorials at The LXD tutorials of Simos