Can I use Adblock/Adblock Plus to block ads in games that are not in a browser?

No, Adblock/Adblock Plus have to install in a browser. Any app that is not a supported browser from this list is not going to be able to make use of it.

GlimmerBlocker is one attempt to block all ads for all applications. I haven't tried it though.

You are going to want to use a hosts file to block all ads in all games. First you're going to have to find the domain name of the server that the ads are coming from. You can use a number of programs to monitor network traffic for this step. My favorite is ettercap-ng, but you might prefer Little Snitch (if you want to do this on a per-app per-port basis, then Little Snitch will be just right for you without having to modify your hosts file). Once you've determined the domain of the ad server you're wishing to block, open up /etc/hosts in your favorite terminal text editor with sudo permissions (sudo nano /etc/hosts) (the file has no extension; it's simply named hosts). Add this line to the end of the file after replacing "domain.com" with the domain you're trying to block:

127.0.0.1 domain.com

This will tell your Mac to loopback when it comes across "domain.com", thus returning nothing, which essentially gets rid of all ads from that server in every app/program/game on your Mac (keep adding more lines for each ad server, and make them all loopback to 127.0.0.1). This method will also work on JailBroken devices and Linux.

If you want to use my omnipotent hosts file that blocks nearly all ads (it was written primarily for my JailBroken iPod), knock yourself out by replacing yours with mine: http://ss.gy/u Mine works on both desktop computers and mobile devices in multiple countries/languages (primarily the United States and France).