Half-Life: Counter-Strike contains all the elements of the popular online multiplayer game originally built as an add-on for Half-Life. While the version of Counter-Strike available online requires a copy of Half-Life, this standalone version contains the Half-Life engine on the CD-ROM. The team-based gameplay divides players into terrorist or antiterrorist squads. Each team has access to different real-world ammunition and equipment, and all players have unique attributes plus the ability to upgrade their gear after completing missions. Missions have different goals, such as defusing a bomb or rescuing hostages. All the multiplayer maps and gameplay from the original Half-Life Multiplayer and Half-Life: Opposing Force Multiplayer are included, plus Team Fortress Classic. Half-Life: Counter-Strike also contains four new gameplay modes of Counter-Strike: firearms, wanted, ricochet, and redemption.