Soldier of Fortune II: Double Helix is a first-person shooter (FPS) for the Microsoft Xbox where players take on the role of John Mullins, a military consultant working to stop the proliferation of biological weapons. The game is known for its realistic depictions of combat and weapon effects, as well as its graphic violence with location-specific damage. The engaging single-player campaign is complemented by various multiplayer modes. Players navigate through a variety of international environments, using an arsenal of weapons to neutralize threats.