C4 (Bomb):

C4 (Bomb) is the planted explosive objective that Terrorists must arm and defend while Counter-Terrorists try to defuse it before it detonates.

It is the central round objective in bomb defusal maps, so control of the bomb site, the plant, and the post-plant defense often decides the round. After the bomb is planted, the attacking side can win by protecting it, forcing the defenders to spend time and utility, or punishing defuse attempts. For the defending side, reading the plant location and managing the timer are critical because a successful defuse ends the round immediately.

For example, on Mirage A site, a Terrorist team may plant the C4 behind default boxes and then hold connector and jungle angles while a Counter-Terrorist attempts a defuse through smoke or with a teammate covering the tap.

Related: Bombsite (A/B Site), Defuse, Plant, Post-Plant