A Counter-Strike: Global Offensive player filed suit against Valve today, accusing the game maker of allowing an "illegal online gambling market" to spring up and propagate around the popular online shooter.

Valve Corporation, the suit says, "knowingly allowed ... and has been complicit in creating, sustaining and facilitating [a] market" where players and third-parties trade weapon skins like casino chips.

The lawsuit filed on behalf of Connecticut resident Michael John McLeod alleges that Valve and third-party sites (CSGO Diamonds, CSGO Lounge and OPSkins) "knowingly allowed, supported, and/or sponsored illegal gambling by allowing millions of Americans to link their individual Steam accounts to third- party websites." Through those websites, the suit says, skins for CS:GO, which can be purchased from Valve, "can ... easily be traded and used as collateral for bets."

"In the eSports gambling economy, skins are like casino chips that have monetary value outside the game itself because of the ability to convert them directly into cash," the suit says.

Valve, the suit alleges, directly profits from transactions tied to gambling.

McLeod’s suit notes that some third-party CS:GO websites don’t require age verification, "which allows minor users to place illegal bets." In his suit, McLeod cites a report from Bloomberg about teenagers gambling on Counter-Strike skins, reportedly part of a $2 billion business.

"People buy skins for cash, then use the skins to place online bets on pro CS:GO matches," Bloomberg reported earlier this year. "Because there’s a liquid market to convert each gun or knife back into cash, laying a bet in skins is essentially the same as betting with real money."

McLeod says he purchased skins from Valve, gambled them — both as a minor and later as an adult — and lost money. The suit is seeking class action status.

"In sum, Valve owns the league, sells the casino chips, and receives a piece of the casino’s income stream through foreign websites in order to maintain the charade that Valve is not promoting and profiting from online gambling, like a modern-day Captain Renault from Casablanca," the suit alleges. "That most of the people in the CS:GO gambling economy are teenagers and under 21 makes Valve’s and the other Defendants’ actions even more unconscionable."

Counter-Strike: Global Offensive was released on consoles and PC platforms in August 2012. A year later, Valve released the "Arms Deal Update" for CS:GO, which added more than 100 decorative skins for players to collect, buy, sell and trade.

With the Arms Deal Update, players could "experience all the illicit thrills of black market weapons trafficking without any of the hanging around in darkened warehouses getting knifed to death," Valve said.

Players can acquire skins in CS:GO through timed drops, by opening dropped weapon cases with the right key or by trading with other players through Steam’s built-in trading interface. Players can buy and sell those skins through the Steam Marketplace. Other Valve games, like Team Fortress 2, feature items and weapons of varying rarity that players can sell and trade.

Counter-Strike: Global Offensive has sold more than 20 million copies, according to data from SteamSpy. The game had more than 10 million unique players in the last month, according to Valve.

We’ve reached out to Valve for response to the suit, which seeks unspecified damages.

You can read the full complaint below.