Some games online require Java to play, however it says that I have a missing plug-in. I am worried that I might get the java-exploit if I downloaded Java, any advice ?
Apple is automatically disabling old versions of Java for security reasons. If you re-install Java you do certainly run a slight risk of exposing your computer to known "in-the-wild" exploits. This is a decision you are best suited to make. Are the games worth installing Java for? Are there alternate places to play the same games without using Java?
If you need to install Java, follow this link to get the latest version.
I would agree with "stay away from Java", but !
Here is an example why:
February 19, 2013, 3:52PM Apple Breached by Facebook Hackers Using Java Exploit http://threatpost.com/en_us/blogs/apple-breached-facebook-hackers-using-java-exploit-021913
Java is great software (and I know how much one likes to play online games) but unfortunately as you can see it can be used by crooks.
You can get some protection by disabling it in the browser. "If you need Java for specific Web sites, a better solution is to adopt a two-browser approach. If you normally browse the Web with Firefox, for example, consider disabling the Java plugin in Firefox, and then using an alternative browser (Chrome, IE9, Safari, etc.) with Java enabled to browse only the site(s) that require(s) it. With that said, it is up to you.