Can you make an HTML file into a theme?

I found a great HTML template that I would like to turn into a theme. Right now it is all just HTML....

Is there a guide on how to make this into a template, I was poking around and thought I could do it using smartypants but it did not pan out...

I want to make a "Dark" template for a disabled gaming site I run (http://www.ablegamers.com) but all of the Drupal templates are far to bright and happy, or to bloggy for a gaming site.

So I found a cool template that is in HTML and want to make it into a Drupal theme.

Is there a "guide" to making HTML based themes? Does anyone want to help on a project like this?

Thank you all for your time, I love Drupal...

Marq