How do I make subforums look like this?
 

<a href="http://forums.fevergaming.com/" target="_blank">http://forums.fevergaming.com/</a>

The forums in that link are what I want to go for, where it has a different theme for each sub forum, and I also want to make it look like they have it, so the sub forums don't show but look like actual forums themselves.

Can someone explain to me how to do this?

Look at your link again...see where it says "Game Communities" at the top?...

Here's what they did...

AdminCP > Forums & Moderators > Add New Forum

After naming it "Game Communities", they left "Parent Forum" to the default "No one"...This makes it a "Parent Forum" itself...In your words, a "theme"...

Then they chose "No" where it says...under "Posting Options"

...

Then, they choose "Add New Forum" again...and named the first one "Battlefield 2"...

Where it says "Parent Forum", they chose "Game Communities"...

Then they kept the "Act as forum" set to "Yes"...

Also, in your admincp, for each and every separate subforums style (theme), go to that forum (edit in the forum manager) and choose your style in the location next to Custom Style for this Forum.

Awsome guys, thank you so much, I'll try doing this to my forums and see how it goes.

Also how did they make it so the link to the forum shows up as
http://forums.fevergaming.com/game-c...battlefield-2/

instead of like a forum id number?

Looks like they have VBSEO

VBSEO? whats that?

http://www.vbseo.com
It's Search Engine Optimization.
The one that is being used it a paid-for version. There are cheaper and free alternatives, but the bottom line is that what these modifications do is rewrite your links (for example instead of seeing xxxxxx.php, you may see xxx.html) or something similar like what you see on the website you got this from. Its most relevant feature is to drive more people to your site as search engines index .htm(l) [static] pages over .php [dynamic] pages. I'm not very familiar with this as I've not used it. But this should give you a rough idea. If someone else can better clarify this, feel free. :)