the "no-charge zone" in Basketball is a little half-circle below the rim. once a player steps into that half-circle than a charging penalty cannot be called.
The introduction of a restricted, no-charge arc at the college and professional levels makes drawing offensive fouls more difficult by marking the minimum distance away a defender must stand to...
This area on the basketball court is known as the restricted zone. If a defensive player is inside the restricted zone, an offensive player who makes contact with him cannot be called for a charging foul. This rule change was added to make the game safer, more fair and easier to referee.
The area behind the arc, or the arc itself is called the "restricted area" (RA) in the NBA, the "restricted area arc" in the NCAA or NAIA and the "no-charge semicircles" in FIBA. Its purpose is to prevent secondary defenders from taking a position under the basket in an attempt to draw an offensive foul while a player is driving to the basket.
The no charge zone arc is a semi-circular arc drawn around the area directly underneath the basket. With some exceptions, members of the defending team cannot draw charging fouls in this area. The no charge zone arc in all North American rule sets above high school level ( NCAA men's and women's, NBA , and WNBA ) has a radius 4 feet (1.22 m) from below the center of the basket.
It is a strategic offensive area especially used against zone defenses. 4' Restricted Area In professional basketball there is a semi-circular 4' restraining area in front of the basket. No offensive charges can be taken by defenders when they are positioned on or inside this area.
The restricted area in basketball court is the segment designated by an arc. This arc is in the painted area and has a position four feet away from the basket. This arc plays a vital role in basketball because, in this area charging foul cannot be forced by the defending player. The restricted area is labeled through a half-circle.
This is the area located under each basket that is outlined by a dotted line, in the shape of an arc. This area, located inside the key, is a place on the court that a charging foul cannot be called by an offensive player. A defensive player cannot spend more than three seconds in the restricted area. This rule was implemented to help reduce the amount of contact underneath the basket, and it gives the offensive player a slight edge when driving to the basket due to the enforcement of this rule.