Foul In, also known as an "And-One", it's when an offensive player is fouled while making a basket, resulting in one free throw attempt.
If the player makes the free throw, they complete a "Three-Point Play". Foul ins often occur on layups or shots near the basket. The offensive player must be in the act of shooting when fouled.
Foul ins reward players for strong moves to the hoop and overcoming contact.
Reggie Miller and Jamal Crawford were known for their ability to convert foul ins. They had a knack for drawing contact on their shots to earn extra free throws.