A headbutt is a strike with the head, typically involving the use of robust parts of the cranium as areas of impact. Effective headbutting revolves around striking a sensitive area with a less sensitive area, such as striking the nose of an opponent with the forehead. It is known as a risky maneuver: a misplaced headbutt can cause more damage to the person delivering the headbutt than to the person receiving it.
Parts of the cranium with thick bone and high local curvature make for good weapon areas, and these include the forehead near the hairline, the outboard curved part of the parietal bone, and the occiput. Ideal targets are usually the fragile areas of the head, including the bridge of the nose, the cheekbones, the hinge area of the jaw, the temple, and the top edge of the eye socket.
Hitting the opponent's teeth or mouth is likely to cause mutual damage. The chin of the enemy is also a generally bad position to headbutt unless striking from below up into the bottom of the chin, similar to an uppercut. With sufficient force, one could cause the opponent to bite through his or her tongue, or slam the opponent's teeth together so hard as to break them against each other. However, headbutting the chin hard enough to accomplish such a task is very difficult.
Headbutts are generally forbidden in most sports.
Headbutting has recently received some attention due to its use by some players during FIFA World Cup matches. Headbutting is considered illegal in association football and is punishable by a red card. In the 1998 FIFA World Cup, Ariel Ortega headbutted Dutch keeper Edwin van der Sar in the Argentina vs. Netherlands quarterfinal match and was sent off. In the 2002 FIFA World Cup, Rafael Marquez headbutted Cobi Jones in the Round of 16 match between USA and lost 2-0. In the 2006 FIFA World Cup another Dutch player, Mark van Bommel was headbutted, this time by Luís Figo in the Portugal vs. Netherlands Round of 16 match, but Figo received only a yellow card for his offense. In the final match against Italy, Frenchman Zinedine Zidane headbutted the Italian Marco Materazzi in the chest, for which he received a red card and a subsequent three match ban (although the red card meant Zidane could play no further part in the match, the three-match ban had no effect since he had previously announced his intention to retire after the World Cup).