Adrenaline is a combat mechanic in the Calamity Mod, a large fan-made expansion for Terraria, where building up the meter rewards aggressive, close-range play with a temporary damage boost when it is activated. Clips of the activation sound circulate among Terraria players and editors who recognise the cue instantly from boss fights and challenge runs. Because it is short, clear and tied to a moment of turning the tables, it has become a handy shorthand in gameplay videos and memes for suddenly gaining the upper hand.