http://gamereuphoria.com/wp-content/uploads/2012/11/steam_linux_love.jpg
Part one of this series of posts can be found here:
http://cheerfulghost.com/panickedthumb/posts/727

Now that you're all set to play, let's talk about how to get games.

The availability of Linux games is growing daily. In addition to big releases, Indie games are becoming a much bigger deal than ever before, and those are far more likely to show up on Linux. One word of advice though: try not to be disappointed when the game you want isn't available, or if it is available but has more bugs and performance issues than its Windows counterpart. We're on our way to more and higher quality releases in Linux but there's still quite a way to go before it's on-par with Windows, and realistically it may never get there. Anyway, on to the meat and potatoes...

Ubuntu Software Center

One great way to get games for your Linux system is just the distribution's software sources. These are generally FOSS games, though. Ubuntu has built the Ubuntu Software Center on top of the standard dpkg/apt system that allows the purchase of commercial software, including games-- some of them AAA releases, or close.

It has it's pros and cons. It's already built into the system, so there's no extra work, just search, buy, and install. The recent Humble Bundles have included an easy shortcut to redeem the games through the USC for easy installation. Getting your games this way eliminates any need to manually install .deb's and manually patch anything, since you'll get updates automatically through Ubuntu's repositories. Overall, it's a major improvement over what it was like a few years back.

However, it does have some problems. If you try to do too much with it at once, it just freezes up for long periods of time. Once you have something installing, you can't do anything else apt/dpkg related outside of the USC for the duration of the install, and for some games that can take a while. It's slow, at most half the speed of other distribution methods, at downloading. There's definitely work to be done, but it's still quite convenient to have on hand.

Steam

This is why we're all here right? The Steam beta for Linux is out, for a select few at least! I won't cover how to get around having an official invitation, but the information is a quick Google search away.

As you'd expect in the early days of a beta, there are a few quirks, but generally this works like Steam in Windows. This afternoon I downloaded Serious Sam 3 and played it for about 30 minutes, and everything worked exactly as you'd expect it to. Big Picture mode and the Steam overlay work perfectly. I won't go into details here, because chances are you know how Steam works already, and this is basically the same. Just don't expect it to be flawless yet if you have the beta officially, and especially if you choose to bypass it. For the faint of heart, it may be wise to wait on a public beta or official release.

Desura

This is a Steam-like game distribution system that, while widely used, is nowhere near as popular as Steam or Origin. It's all indie games, all the time. There's even a kind of Kickstarter-type system built into it for funding proposed games.

If you purchased some of the earlier Humble Bundles, you have gotten keys for Desura. I'm not sure why they took them out of the later bundles, but activating them is a snap, and they then get added into your list of games for you to download at your leisure, just like Steam. IndieGala and Groupees BeMine bundles still come with some games that have Desura keys, and all the games in IndieRoyale bundles have Desura keys (most also have Steam keys). Which makes sense, since Desura runs the IndieRoyale bundles.

I downloaded Trine and VVVVVV earlier in Linux to test things out, since I haven't used it much outside of the Windows version, and it worked quite smoothly. It has all the basic things that Steam has, just arranged differently at times.

Manual Installs

It's rare these days, but occasionally you're going to find something you have to install manually. Luckily, in most distributions, it's easier than ever. You can usually download a package specific to your distribution that will install automatically and handle dependencies with a double-click. Even in the times when you're presented with a .tar.gz that you have to extract, most packages have a clear README to tell you exactly what you need to do. There's little else to explain here, since each case will be different, but rest assured-- complicated installations in Linux are far more rare than they used to be.

So now you know the basics for getting your games running in Linux. Go forth, kill some zombies, save the princess, stop the alien invaders, and be awesome.