In bomb defuse maps, a member of the terrorist team will be randomly chosen to be equipped with the C4. TR team with the C4 then must plant it at designated areas, either one of the two points in the map, and then defend it from being defused by the counter-terrorists until it explodes. When planted, the C4's timer is set to blow within 35 seconds. Should the C4 detonates successfully, TRs will win even if there are some CTs still alive. If all players on the TR side are dead while the C4 is still ticking, the round will continue until the bomb is defused or detonated.
C4's appearance isn't restricted to bomb defusal maps:
It appears in Battle Rush as the Counter-Terrorist's equipment, which needs to be used to destroy roadblocks. TRs must defuse the bomb to prevent CTs from advancing.
In some Zombie Escape maps, C4 appears for destroying obstacles, or making barricades to slow zombies down.
C4s are available in New Zombie Shelter mode for the Engineer class players who have reached Tier 4. In this mode, C4s can be used to destroy various obstacles and create shortcuts in the map. Properly planted C4 can eat large chunks of a bosses' health, which can make battles with bosses much easier.
