A "safety" in American football is a scoring play that occurs when the defense tackles an offensive player in their own end zone or when the offense commits a penalty in that zone. This results in the defense earning two points, and the offending team must then perform a free kick from their 20-yard line. Safeties can also happen through other scenarios, such as a blocked kick going out of bounds in the end zone. The concept of safety is crucial in understanding game strategy and score progression.