A free-to-play online FirstPersonShooter developed by the South Korean studio Doobic Studios and published by Nexon. Players in the game are split into team Alpha and team Bravo, and duke it out on a variety of maps.

[[AllegedlyFreeGame The game has a rental system when it comes to its weapons and gear.]] Everyone in the game gets an M16, a M9, a knife, and a grenade as default gear, but as the game is played, they earn GP or gear points, which allows them to rent new guns and accessories for an amount of time.

The game also features the Black Market, an in-game shop in which the currency is NX points, which are purchased with real money. This shop includes new character models, guns with cooler looks, double xp abilities, and the ability to change the default weapons permanently to better weapons.

Like many recent first-person shooters, ''Combat Arms'' consists of game modes such as Team Deathmatch (known as Elmination) and One Man Army (Free-For-All). The game also has a ranking system based on military ranks. The higher the player is ranked, the more gear they can rent in the shop (although the black market has no rank restriction.)
----
!!This game provides examples of:

* AllThereInTheManual: There's little by way of ingame explanation, and it seems as though a great deal was lost along with the original Fireteam mode. Given the blurbs for each level and buyable merc do little to connect to each other, you could be forgiven for thinking there was [[ExcusePlot no plot at all]].
** It's there on the game page, but you're probably not looking for it.
* AllegedlyFreeGame: Not as bad as other examples, really. If you're good enough, you can still kick ass with your basic gear.
* AndYourRewardIsClothes: Somewhat subverted, as the new clothing accessories you unlock as you rank up can be give your player benefits such as protection from headshots, but a good deal of it just plays straight the RuleOfCool.
* AnnouncerChatter: Every time you respawn, you are treated with a "round start" from an announcer, which makes little sense as you are just respawning, not starting the whole game over again. Also, the end of the game is announced with a "X teams wins!"
* AirVentPassageway: You can hide in one when people are turning into zombies.
** Watch out for the [[CaptainObvious poison gas]].
*** You can hide in the same vent when people aren't turning into zombies now, but the poison gas is still there. Instead of zombies, you will find your [[OhCrap opponent's spawn area]] if you exit the vent.
* AwesomeButImpractical: You can buy an Airstrike Designator, but if the enemy doesn't know to get away from the glowing orange beacon in the quarter-minute it takes for the strike to arrive, [[TooDumbToLive you probably could have run up and shot them without much trouble.]]
** Much more practical in Cabin Fever, where the zombies are obviously too stupid to get out of the flare warning before they get pumped full of napalm.
* BlueNoseBowdlerizer: The in-game chat censors out swear words, including words such as s'''[[ScunthorpeProblem nip]]'''er.
** Thankfully, you can turn off the curse filter now, and swear to your heart's delight. Which most players do.
* BoomHeadshot: Scoring a headshot will result in the player being rewarded with a quick picture of a skull with a bullet hole, with the words Headshot! written below them.
* BribingYourWayToVictory: Some of the better weapons and gear can only be bought with real money. Some weapons are simply more stylish (the G36E Valkyrie), while others are distinctly improved. Most weapons pale in comparison to the gear offered, including much-improved combat vests, and the commonly seen 'speed gear'.
* CoolGuns: Some of the weapons and weapons skins you can pick up in the shop and black market, [[BlingBlingBang gold plating]] among them.
* CriticalExistenceFailure: You can run around with 1 HP, but fall down several feet and...
* DoesThisRemindYouOfAnything: When Quarantine mode was released, a [[http://combatarms.nexon.net/FunStuff/Wallpaper.aspx promotional logo]] was made, with [[http://www.l4d.com/blog/ a bit of influence from]] [[VideoGame/Left4Dead a certain other game.]]
* EasterEgg: At one point, delving into some of the games files and looking into some user configuration text files revealed some leftover bits including such variables as "vehicle turn speed" and "toggle night vision." While the night vision was actually teased (before it was changed) by a loading screen for the map Rattlesnake with a picture of a merc using a pair of goggles with a pistol drawn, none of it never came to be. In subsequent updates, the variables were removed.
* EverythingsDeaderWithZombies: Quarantine Mode, which was added in the July 28th patch of 2009.
** And expanded with Fireteam's 'Cabin Fever' map. The plot currently deals with a potential ZombieApocalypse in the making.
* FacklerScaleOfFPSRealism: Zig-zags between Classic and Realistic. Matters of accuracy, sprinting, and weapon carrying capacity stay mostly realistic, but balance always comes first, leading to the ability to take a rocket launcher to the face [[MadeOfIron and keep going]].
* FanService: Cmon, how could you NOT think of the mercenary specialist [[DistractedbytheSexy Viper]]?!
** Nobody really does explain how her body armor makes use of ''[[SexyBacklessOutfit her back being completely exposed]]''.
** Further played by another specialist, Raven, though she does not wear a [[TooDumbToLive backless outfit]] like Viper.
* Griefer: The game has a long history of hackers, leading to interesting situations in which people convinced decent players are hacking can actually cause more trouble than the hackers themselves, depending on how recently the various exploits have been patched.
* GroinAttack: Originally added in as an April Fools joke, but later kept in as a permanent feature, shooting male characters in the family jewels will result in what was once a one-hit-kill like headshots, but later {{Nerfed}} to only show up if the killing bullet (or melee attack) was delivered to the groin area. At any rate, getting a kill in this fashion will result in the hearing your character laugh evilly, and a picture of two cracked nuts will flash on the screen.
* HyperspaceArsenal: Subverted. Bigger backpacks allow players to carry more gear with them, even more weapons, with the cost of reduced speed.
* KatanasAreJustBetter: While technically a not a katana, the Ninjato, which is close enough in looks, is a pretty effective melee weapon. It was considered a GameBreaker in melee-only matches because of its long reach and NX exclusive nature, before the advent of higher-grade speed gear, and more recent GP offerings.
* LevelGrinding: Once you start getting into the "Field Officers" area, this starts to show up.
* MeaningfulName: The given name of the town Waverider takes place in is [[PunnyName "Rupheria"]]
* OneBulletClips
* RareGuns : Combat Arms plays this trope to hell and back. It has, at this point, 12 guns that are listed on the Rare Guns page alone.
** Another notable example would be the [=M16A3=], the least common version of the M16 ever made, is the default gun which every player starts out with.
* RevolversAreJustBetter: While it might not make much sense, many of the old Civil War revolvers are this, especially the [=C1851N=]. It shoots extremely accurately for a handgun, and it also manages to shoot faster than the Anaconda- with comparable power. If that wasn't enough, it has a large amount of ammo compared to other pistols, and it reloads extremely quickly.
* RuleOfCool: Some of the accessories and gun skins fall under this. They don't do really anything else but follow this rule.
* RuleOfFunny: Some of the items found in-game can be this, like exploding football grenades and oversized turkey leg clubs.
* ShoutOut: kind of an EasterEgg--the Waverider map has the [[TengenToppaGurrenLagann Dai-Gurren Brigade]] flag ([[BlandNameProduct sans sunglasses]]) in pendant form.
** The boxes found through many maps say [[Franchise/MetalGear "Not Suitable for Solid S"]]
** As of the 2012 St. Patrick's Day update, [[Film/JamesBond The Gold Gun]] is now available for use. It does not kill in one hit, however.
* StandardFPSGuns
** One obscure exception: Waaaaaay back when Combat Arms was still in the open beta/public release timeframe, a glitch with the knife would cause what seemed to be a smoke signal followed by a somewhat large glowing target on the grown to appear, along with the words "Incoming Artillery." This was never realized in the game, even to this day.
* SortingAlgorithmOfWeaponEffectiveness: As you rank up, you gain access to better weapons. This adds a bit of fridge logic as well, as the M16, the default gun, is less powerful than the M4, which is just a carbine version of it and ''fires the same round.''
* SniperScopeSway: Every sniper scope does this.
* TakeCover: Most maps have waist high objects you can crouch behind and shoot.
----