In video games, skin gambling (also known as skin betting) is the use of virtual goods, often cosmetic in-game items such as "skins", as virtual currency to bet on the outcome of professional matches or on other games of chance. It is commonly associated with the community surrounding Counter-Strike 2 (the successor to Counter-Strike: Global Offensive), but the practice exists in other games such as Electronic Arts's FIFA. Valve, the developer of the Counter-Strike series, also runs the Steam marketplace which can be interfaced by third-parties to enable trading, buying, and selling of skins from players' Steam inventories for real-world or digital currency. Valve condemns the gambling practices as it violates the platform's terms of service.

Valve added random skin rewards as part of an update to Global Offensive in 2013, believing that players would use these to trade with other players and bolster both the player community and its Steam marketplace. A number of websites were created to bypass monetary restrictions Valve set on the Steam marketplace to aid in high-value trading and allowing users to receive cash value for skins. Some of these sites subsequently added the ability to gamble on the results of professional matches or in games of chance with these skins, which in 2016 was estimated to handle around $5 billion of the virtual goods. These sites, along with Valve and various video game streamers, have come under scrutiny due to ethical and legal questions relating to gambling on sporting matches, underage gambling, undisclosed promotion, and outcome rigging. Evidence of such unethical practices was discovered in June 2016, and led to two formal lawsuits filed against these sites and Valve in the following month. Valve subsequently has taken steps to stop such sites from using Steam's interface for enabling gambling, leading to about half of these sites closing down while driving more of the skin gambling into an underground economy.

Counter-Strike is series of team-based first-person shooter developed by Valve that debuted in 1999. Players in the game take the role of a terrorist or a counter-terrorist, with each team having a unique goal to complete before they are eliminated by the opposing team or before the timed round is completed. For example, the terrorist team may be required to plant and defend a bomb at a specific site, while the counter-terrorists must eliminate the terrorists before it can be planted, or disarm the bomb once it has been activated.

The introduction of the Arms Deal update to Counter-Strike: Global Offensive in August 2013 added cosmetic items termed "skins" into the PC versions of the game. The developers had considered other types of customization drops for the game before coming to weapon skins; they had ruled out on player skins, since Global Offensive is a first-person shooter and the player would not see their customization, as well as new weapons, fearing this would imbalance the game. Following the model they used for Team Fortress 2, Valve enabled players to be rewarded with random skin drops as they played matches which would be stored in their user inventory within Steam, Valve's software delivery and storefront client. Limited-time "souvenir" skins could also be earned by watching competitive Global Offensive matches within the game or through a Twitch account linked to a Steam account. Unlike Team Fortress 2, the Global Offensive skins do not have any direct impact on gameplay, only influencing the look of a player's weapon. Skins, unique to specific in-game weapons, are given several qualities, including a rarity that determines how often a player might acquire one by a random in-game drop just by playing the game or as in-game rewards, and an appearance quality related to how worn the gun appeared.

These skins were added to try to unify and increase the player size of the community, who were split between Global Offensive, Counter-Strike v1.6, and Counter-Strike: Source. According to Valve's Kyle Davis, the introduction of skins to Global Offensive was to encourage more players for the game by providing them free virtual items simply by playing the game which they could then use as part of the Steam Marketplace to trade with others, boosting the Marketplace's own economy. The Arms Deal update drew an audience back to the game, with a six-fold increase in the average number of players from the previous year about seven months after its release.

Initially, Valve had considered skins that appeared as camouflage would be more desirable to help hide on some maps, but found there was more community interest in bright, colorful skins that made their weapons appear like paintball guns. The addition of skins made the game attractive to expert players, as the skins could be taken as a kind of trophy, showing off to other players how serious of a player they were. Valve's CEO Gabe Newell described the offering of skins as an "investment" that would retain some nominal value well after the player stopped playing the game, though Newell noted Valve had concerns about factors that might fall outside of their control with the feature.

In 2023, Valve released the successor to Global Offensive, Counter-Strike 2. Players' inventories of digital goods were automatically transferred over from CS:GO over to CS2, with the skins recreated in the new game. In the year 2023 alone, it was estimated that Valve earned US$1 billion from the sale of weapons case keys and commission from user-to-user trades in the Steam marketplace.

Because of the rarity and other qualities, certain skins are highly sought after by players. Skins are a form of virtual currency, with some items like special cosmetic knives worth thousands of United States dollars. This virtual currency is further impacted by the game giving out "weapon cases" that contain an unknown randomized skin, which can only be opened by purchasing a key in the in-game store for $2.49. The most common skins that can be obtained have a value far less than the cost of the key, so the player would effectively lose money if they bought a key and found a common skin. Because of this, cases are also part of the virtual currency within Counter-Strike.