A flagrant foul is a serious contact foul involving unnecessary and/or excessive and/or intentional contact in sport. There is a specific National Basketball Association foul termed a flagrant foul.
Types of flagrant fouls
The flagrant foul rule is described in several subsections of NBA Rule Number 12. The most extensive section is 12B (Personal Fouls) Section IV (Flagrant Fouls). There are two types of flagrant fouls defined: flagrant 1 and flagrant 2. Flagrant 2 is the more serious infraction. A flagrant 2 foul results in immediate ejection, whereas two flagrant 1 fouls are required before the player is ejected. Although the delineation between these two rules has evolved, the general distinction has been whether the excessive contact was intentional.
FIBA rules
FIBA basketball rules have a similar foul called an unsportsmanlike foul, which is roughly equivalent to a flagrant type 1, with the addition that an unsportsmanlike foul can be called if a player fouls with no intention to play the ball, as well as if a player fouls another player on a fast break from behind him. If a player commits a foul warranting immediate ejection from the game, the foul would be called as a disqualifying foul - similar to a flagrant 2. Two unsportsmanlike fouls lead to automatic disqualification, similar to the NBA.
The penalty for an unsportsmanlike or disqualifying foul is two free throws and possession at midcourt for the opposing team. If a player is disqualified for two unsportsmanlike fouls, there is no additional penalty for the disqualification: only the second unsportsmanlike foul is punished, just like the NBA.
NCAA and NFHS basketball rules
NCAA (college) and NFHS (U.S. high school) rules define a flagrant foul as a personal or technical foul that is extreme or severe.
* A flagrant personal foul (or intentional foul) involves excessive or severe contact during a live ball.
* A flagrant technical foul involves unsportsmanlike conduct that is extreme in nature, or excessive or severe contact during a dead ball. Fighting is also considered a flagrant technical foul.
The penalty for a flagrant foul in NCAA and NFHS rules is immediate ejection of the offending player, plus two free-throws and a throw-in for the opposing team.
* For a flagrant personal foul (or intentional foul), the throw-in spot is at the out-of-bounds spot nearest the foul.
* For a flagrant technical foul, the throw-in spot is at the division line opposite the scorer's table.
Source: Wikipedia