Yes. Yes you can.
More? Ok.
This is actually two questions. Can you game on OSX? Sure, you can. You can get Steam, Battle.net, and so much more all on Mac now. The other question is can you game, for real on a Mac? And by that I mean, installing Wndows, and running serious games at decent frame rates at high resolution. You shouldn’t expect industry leading performance, but the answer is yes here too.
Let’s start with gaming on OSX. The library of titles isn’t remotely comprehensive, but there are a lot of big titles and smaller indie games that absolutely do support the Mac. Thanks to efforts like the Humble Indie Bundle, Apple’s own gaming support, and most importantly the swath of multi-platform frameworks like Unity and Gamemaker the mac is now home to a healthy sampling of the best gaming has to offer.
If you’re running any model of MacBook Pro, you should be able to run most of these indie titles and quite a few bigger titles without a problem. If you’re looking for honest to goodness AAA gaming, though, this is not your bag. Apple is well known for walled gardens and gaming is no exception. This is where Boot Camp comes in.
Boot Camp works beautifully. Once you’re all up and running with a copy of windows on your mac, sky’s the limit. Actually, well, the limit is actually your graphics card. And that’s where a PC beats a mac. On a mac, you’re stuck with what you bought out of the box. No expandability. A PC can just swap in a powerful graphics card if necessary, but here you’re definitely going to be dialing down the quality settings in your games quite a bit.
