“Everyone likes to play games, and that’s been true for 5,000 years,” says PopCap Games spokesman Garth Chouteau. “You can go back and find hieroglyphics of Egyptians playing games. It’s practically in our DNA.

Whether it’s used to describe a vast, profitable swath of the video-gaming landscape or derisively in a review of the latest minigame collection, there’s no question that the label “casual game” carries more than its share of baggage. For something that’s so ubiquitous, it’s a concept that’s surprisingly hard to nail down; ask 10 developers to define what makes a casual game, and you’re likely to get just as many responses. Chances are, though, no matter how hardcore you might consider yourself, if you’re reading this, you’re also probably a casual gamer, too.

Casual What?

“We define it as a gameplay behavior,” says Jessica Tams, managing director of the Casual Games Association, an international trade association founded in 2005 to represent the growing segment. “We don’t think about a consumer demographic, because everybody plays casual games. We don’t think about platforms, because they’re available on all types of platforms. We don’t think about gameplay mechanics, because there are many different types of gameplay mechanics in casual games. What we ask is, ‘How is the user interacting with that game?’ So you would say that solitaire is a casual game, because [players] interact with it in short time slices. They do not have to play it for long periods of time, and it’s very easy to learn but kind of hard to master. It’s continually playable, but it’s something that you can learn almost immediately.”

Tams contrasts the casual-game experience with that of World of Warcraft, which can require a lengthy time commitment. “It’s doesn’t mean that [players] don’t spend a long time playing casual games, because they do, it’s just that that choice is there. You don’t have to play.”

“I’ll use the classic senatorial response on pornography, where ‘I don’t know what it is, but I know it when I see it,’” adds casual-game publisher Majesco’s Executive Vice President of Operations Gui Karyo.

Solitaire is perhaps the perfect example of a casual game. Launched in 1985 and packed in with Microsoft Windows, the addicting card game was a perfect reintroduction to gaming for legions of office workers. If you were to stop time and stroll through just about any office nationwide, you’d likely see a game of Solitaire on someone’s screen (or minimized to the Taskbar if a boss is frozen nearby). And its popularity doesn’t seem to show any sign of slowing—Microsoft says it’s the most commonly opened application in Windows XP.

Of course, if Solitaire was all there was to talk about, there certainly wouldn’t be much of a casual-games industry. Solitaire’s popularity owes much to the fact that it is included with new PCs, so it’s not exactly a title that people have to chase down to play. Using the CGA’s definition, games like chess, bridge and even (gasp!) Guitar Hero fall squarely in the casual-games domain. Here’s a potentially terrifying thought to ponder the next time you finish shredding an Iron Maiden song on expert—you have more in common with that mouse-clicking office drone than you might care to admit.

“We should have called ourselves ‘The Games Association,’ and then forced everyone else to rename themselves according to their niche markets,” jokes Tams.

While the CGA might want to focus on the behavioral aspects of casual games, it’s that word—casual—that seems to stick in the throats of others.

“We often say that casual is a real misnomer—especially as it relates to Pogo, because there’s nothing casual about a lot of these players,” says Andrew Pedersen, vice president and executive producer at EA’s Pogo.com. “They’re as hardcore as any console player that I’ve interacted with.”

Regardless of whether or not you think the definition of casual games is ideal or even accurate, one thing isn’t up for debate—casual games are huge. According to the CGA’s Casual Games Market Report 2007, more than 200 million people play casual games each month online. And each of those players is making some company, somewhere, money, whether through subscription fees, advertising or microtransactions.