Which is honestly not a surprise, so it's time for an upgrade. (Incidentally, I don't know why it says I'm running DirectX 10; I know it's actually DX 11.)
Minimum system requirements include NVidia Geforce 460GTX or AMD Radeon HD5850. Recommended is GTX 670 or higher, and to run smoothly at maximum graphics settings they recommend a GTX 780.
I know what to do with getting and installing cards, but my concerns are power supply and cooling. I take it as a given that I'll need to upgrade the power supply (currently 300W), but cooling is my major concern. My current card's thermal design power is 11W, while I'm looking at cards with TDPs of 160W or greater. Can the stock fans handle it, or will I need to add more and/or replace the case?