Rainbow Six Siege is Ubisoft's tactical shooter released in 2015, where breaching tools and placed explosives are central to each round. The C4, often called the Nitro Cell in game, is thrown or placed by defenders and detonated remotely to stop attackers pushing through doors and barricades. Its beeping warning and blast became familiar to players from countless rounds and clips shared online. Outside the game, the sound is reused as a generic gaming explosion cue for traps, breaches, and sudden endings in edits and streams.