CrossFire is a first-person shooter that features two mercenary corporations named the "Black List" and "Global Risk," fighting each other in an epic global conflict. Players assume the role of either a Black List or Global Risk mercenary, joining an online team that must work together to complete objective-based scenarios. With the exception of the Zombie mode and Wave mode, each mode can support a maximum of 16 players (except Wave mode), each divided into an 8-man team (5 for Wave mode).

There are more than ten online modes: Team Death Match, Search and Destroy, Elimination Match, Ghost Mode, Free-For-All, Mutation Mode, Escape Mode, Hero Mode, Hero Mode X, Zombie mode, Elite mode, Wave Mode, Shadow Mode, Biochemical Knight Mode, Ghosts vs Mutants, RPG/Melee Mode, Soccer Mode, Light Mode, and Super Soldiers TD.

Based on their performance in-game, players will receive experience points and be promoted through various Military Ranks. The lowest rank is trainee first class, the highest is Marshall. Players also have the ability to customize their character's equipment and appearance through CrossFire's in-game item shop and from the Mall in the website.

CrossFire is free to download and playable online. It has a free currency which is called Game Points (GP), which are earned through playing and completing matches, buying premium items that grant bonus GP, or fulfilling certain missions. Premium and special items like modified weapons can only be bought using points which are obtained using real money in the form of cards or online transactions. The content and the name of the points tends to vary from version to version.