If you hang around gamers long enough, eventually you’ll discover the online comic Penny Arcade. It has been around for nearly a decade now, and in that time the thrice-weekly strip has grown into a mini-empire with an annual convention and an ongoing charity program that has raised millions of dollars in cash and gaming products for children’s hospitals around the world.

For all its popularity, Penny Arcade can be an acquired taste. Understanding the punchline usually requires a close familiarity with gaming terms, culture and trends. The strip jumps right into things with no preamble, and assumes the reader has the knowledge of minute game-related details, news and the comic’s own history needed to get the joke (Jerry Holkins aka Tycho, the writer of the comic, types up a lengthy newspost to go with each strip that explains the context). Take this one, for example:

That’s pretty straightforward for a Penny Arcade comic, but if you don’t get it, trust me — it’s funny. It’s also quite clean — the strip (and newspost, even) frequently features profanity and violence, so readers beware.

Now, this comic about video games has become a video game itself. Click that link and you can download a demo for Windows, Mac or Linux operating systems; there’s also a demo available on the Xbox Live Arcade, for you Xbox 360 owners. But please, don’t be misled by the comic art — the game is rated Mature for a reason. Type the title into this blog’s ESRB widget to see the criteria.

The full version of the game, titled “Penny Arcade Adventures: On the Rain-Slick Precipice of Darkness,” is about $20, and is the first of several planned “episodes,” gamelets that connect to form a larger adventure. The setting is a version of the 1920s filled with Lovecraftian creatures and steampunk creations. The gameplay looks to be a mashup of classic point-and-click adventure games, like the “Monkey Island” or “King’s Quest” series, and turn-based battles like you might find in a Japanese role-playing game.

Tycho handled the writing duties, and Penny Arcade artist Gabe (aka Mike Krahulik) did the visual and character designs. The title was developed by Hothead Games, and the non-Xbox 360 versions are being distributed through a fledgling service called Greenhouse.

(Image courtesy of Penny Arcade)