Dark Sector is a third person shooter video game for the Xbox 360, PlayStation 3 and Microsoft Windows developed by Digital Extremes. The game was released on March 25, 2008, in North America, March 27, 2008, in Japan and April 4, 2008, in Europe
Set in the crumbling infrastructure of a fictional Eastern Bloc country in the near future, the game features both single and multiplayer action, with players working their way through a world where biological weapons are a hellish nightmare, let loose on an unsuspecting populace.

In Dark Sector, the gameplay revolves around the use of the glaive. The glaive is a three pronged boomerang esque weapon which returns to Hayden after every throw. The glaive can be used for long distance dismemberment, solving environmental puzzles, and picking up various items. When up close to an enemy, context sensitive actions may appear, allowing the player to execute enemies with finishers. Environmental puzzles in the game usually focus upon capturing various elements (fire, electricity, and ice) with the glaive. For example, a web that is blocking your path can be bypassed by capturing fire with the glaive and then launching it at the web to burn it down. The glaive is dual wielded with a gun in Haydens left hand. This allows for combos like stunning a shielded enemy at long distance with the glaive and then shooting him while unprotected. As the game progresses, the glaive is given several new abilities; it can be guided through the air, being able to kill multiple enemies (This feature is controlled via the Sixaxis on the PlayStation 3 and by the right analog stick on the Xbox 360); a charged up throw for deadlier attacks, and is able to make the user invisible for a short period of time and also provide a temporary shield.

The camera is positioned over the shoulder for third person shooting, and the player can also take cover by standing next to an object such as a pillar or wall. While in cover, the player can pop out and fire, and also throw the glaive; however there is no blind fire. There is also a sprint function, which works similar to that of Gears of War. there is also a simple melee attack that allows the player to punch or slice the enemy. The game has no HUD (except for the ammo counter); Haydens health is shown by the screen flashing red when he takes damage. If the player takes too much damage, the flashes will be faster, and a heartbeat will be heard, indicating Hayden is bleeding out.