How does a team score a safety in American football?

Answer 1

6 points for a touchdown

1 extra point after a touchdown if a field goal is kicked

2 extra points after a touchdown if a two point conversion is run

3 points for a field goal if a touchdown is not scored

2 points for a safety

Answer 2

Well, it's pretty rare, but they are worth 2 points.

A safety is scored by the opposing team when the team in possession at the end of a down is responsible for the ball becoming dead behind its own goal line. For instance, a safety is scored by the defense if an offensive player is tackled, goes out of bounds, or fumbles the ball out of bounds in his own end zone

Team A is lining up in their own endzone (offense) and a defensive player forces a tackle behind the offense's goal line.