The Hail Mary has become the signature play of the NFL. It is a simple desperation play performed usually as the last play of the game where all eligible receivers run the length of the field and the quarterback throws the ball usually into a crowd of players and hopes his team comes down with the ball. There are variations of this play but in principle it is an all out pass. 

The Play has its origins from Notre Dame University a catholic school with a historic football program. But it came into popularity and got its name during a playoff game between the Dallas Cowboys and the Minnesota Vikings in 1975. Roger Staubach dropped back to pass with the game on the line and received excellent protection and completed a long throw to Drew Pearson for the game winning touchdown. Staubach later said that he dropped back, said a Hail Mary and threw the ball. With that the play was named.