Unsportsmanlike conduct (also called unsporting behaviour or ungentlemanly conduct or bad sportsmanship or poor sportsmanship) is a foul or offense in many sports that violates the sport's generally accepted rules of sportsmanship and participant conduct. Examples include verbal abuse or taunting of an opponent, an excessive celebration following a scoring play, or feigning injury. The official rules of many sports include a catch-all provision whereby participants or an entire team may be penalized or otherwise sanctioned for unsportsmanlike conduct.
In American football, unsportsmanlike conduct results in a 15-yard penalty (or 10 in the AFL), assessed after the completion of a play. When it occurs after a scoring play, the 10 or 15 yards are assessed on the kickoff. Situations that can incur such a penalty include excessive celebrations after plays, often involving props or multiple players or engaging in taunting against an opponent; a player's purposeful removal of his helmet anywhere in the field of play during or in between plays; or if a substitute leaves the team bench during a fight. Unsportsmanlike conduct can also lead to players or officials being ejected from the game if the conduct is found to be flagrant. In the NCAA, NFL & AFL, two unsportsmanlike conduct fouls lead to the offender's ejection. The referee signals unsportsmanlike conduct by holding his arms outstretched with palms facing downward. Coaches can also receive an unsportsmanlike-conduct penalty for taunting, arguing with, or abusing officials, one of the few times a coach's actions can be penalized outside of the rare palpably unfair act penalty; but can't be ejected. In Canadian football, the equivalent penalty is objectionable conduct and only carries a 10-yard penalty.
In association football, the term "unsporting behaviour" is more commonly used, being one of the listed reasons under law 12 of the laws of the game for which a yellow card may be given. It is interpreted broadly, most commonly to sanction fouls which are more serious than most, though below a level which would merit a red card. Other examples include extravagant goal celebrations (e.g. removing one's jersey) and simulating actions intended to deceive the referee (diving).