Combat Arms gameplay is similar to commercial games such as Counter-Strike and Call of Duty[2]. The game offers many different modes of play, including One Man Army and Elimination and variations with objectives, as well as multiplayer co-op called Fireteam mode and Quarantine mode. During winter, a special mode of Snowball Fight is unlocked. Combat Arms uses a player ranking system based on total experience, using common military ranks that players can obtain. Completing objectives, killing other players, and levelling up one's rank gives the player money in the form of Gear Points (GP), which can be used to purchase new weapons and accessories. All items purchased have a time length of anywhere from 1 to 90 days, after which the gear is deleted from the players inventory. Players can also purchase equipment from the Black Market[3] (also known as Nexon Cash Shop) using points that are bought with real-world money. Primarily, the Black Market equipment is cosmetically differing equipment of regular shop items and has no typical requirements that many of the free items require.
The game boasts customizability that includes female player models.

Combat Arms has over 300,000 registered players. Because of the limited availablity of spots in high ranks, competition can be fierce, which has resulted in teamwork as a legitimate means to attain high ranks. The game supports community features such as clans and an in-game friends' list. There are also some professional gaming leagues, such as the World Online Gaming League, that support Combat Arms and organize clan battles.