The offensive foul is a judgment call by the referee, and it often generates a protest from the player cited and his coach. Although the rules for an offensive foul are clear in rulebooks, not every offensive foul is the same, and it can depend on the positioning of the defensive player. The NBA offensive foul is also slightly different than non-professional leagues.
Offensive Fouls and Penalty Rules
Any illegal contact, such as throwing an elbow, pushing or punching is an offensive foul. The offensive player cannot gain an advantage through illegal contact, like an illegal screen. A player setting a screen must remain still and in position. In addition, the NBA rulebook specifies the rules for offensive fouls that are not elbowing, punching or flagrant fouls. The rulebook says the offensive team gets no points and the offending player gets a personal foul, but the team does not get a team foul, according to NBA.com. The exception to the rule is if the offensive foul occurs after the ball has gone in the hoop. The offensive player is still charged with a foul, but the basket counts. This usually occurs after the ball has gone in, and the offensive player is coming down out and lands on a defensive player who has maintained his position.
A charging foul is a common form of an offensive foul. The referee will call a charging foul when the offensive player runs into a defensive player who has established a position on the floor, according to ultimate-youth-basketball-guide.com. The defensive player cannot be moving when the offensive player runs her. If the defensive player moves, it is a blocking foul.
NBA "No Charge Zone"
The NBA has an additional rule regarding offensive fouls that the high school and college level do not have. The "No Charge Zone" is a half-circle underneath the hoop where defensive players are not allowed to draw offensive fouls. If the defensive player is inside the half-circle, or has a foot on the line when the offensive player runs into him, the defensive player is called for a blocking foul, even if he establishes a position under the hoop.