Criminal Law
Contact Sports
Contact sports may raise issues in relation to criminal liability for a person’s act wholly outside the rules. Some so-called sports may be criminal in themselves. Some sports involve actions which, without the consent given in the course of the rules, will constitute criminal assault.
A person participating in sports consents to activities within the scope of the rules of the game. Any touching or physical contact would constitute common law assault or battery in the absence of consent.
The criminal law places limits on the extent to which it is possible to consent. It is not permissible to consent as a matter of public policy to certain infliction of serious injuries or cause significant harm.
Consent and Playing Game
It has long been accepted that that properly conducted games and sports are an exception to the general rule and are a defence to “simple assault”. This is justified by reference to the organised structure and presence of a referee.
The Non-Fatal Offences against the Person Act provides that consent is a defence to simple assault. It is also implicit that it applies to assault causing actual harm.
However assault causing serious harm, which is defined as injury which creates a substantial risk of death or which causes serious disfigurement or substantial loss or impairment of the mobility of the body as whole or of the function of any bodily member or organ appears implicitly not do allow a defence of consent.
The Act preserves the common law rules in relation to defences of  lawful authority and justification. It appears that the position is that one may not consent to assaults which may carry a serious risk of bodily injury or death.
Boxing
Questions have been raised regarding the legality of boxing. Although immediate serious injuries are not common, more common are chronic conditions that later develop which are traceable to boxing. Arguments can be made that boxing is contrary to Offences against the Person Act. However, given its wider scale acceptance, it is unlikely to be held so.
19th-century case law held that bare-knuckle prize-fighting could be the subject of criminal prosecution, regardless of consent. Those persons present might be held guilty of aiding and abetting crime. The court also laid the emphasis on the possibility of riot, affray and  breach of the peace.
It appears that boxing is not unlawful or criminal whether for reward or not. A contestant in a boxing, sport or contest, is not for motive of personal animosity  but predominantly is an exercise of boxing skill and physical condition in accordance with rules and conditions.
The infliction of bodily injury is kept within reasonable bounds so as to preclude or reduce so far as practicable, the risk of either contestant incurring serious bodily injury Victory is to be achieved in accordance with the rules by a person demonstrating the greater skill as a boxer.
In many respects, boxing remains an anomaly, which is unlikely to be found contrary to common law, given its long-standing duration and acceptance.
On-Field Violence
On-field violence in sport outside the rules of the game, is subject to ordinary principles of criminal law, violent foul play may constitute criminal assault. So-called bust-ups in matches may constitute assault.
A footballer, who assaults another player in the football field, is not entitled to expect leniency from the court just because the incident occurred in the course of a football match. On the contrary, one of the factors that may indicate the gravity of the offence is the fact that it has been committed in public before so many spectators. This is all the more so where the player is a public figure and the incident occurs during a high-profile game.
In a soccer match, 19th-century soccer match player was convicted where he jumped into the air and struck an opponent in the stomach with his knee. It was held that such conduct causing serious harm such that as no sports could make legal.
In 1898 case, a launched kick in the back leading to internal injuries and death was a subject of a conviction for manslaughter. Both in civil and criminal law, it is likely that a player will be deemed to consent to conduct and behaviour wider than that permitted by the rules. Difficult however to define the extent to which there may be implied consent to contact and beyond the rule.
Off the Ball Violence
Courts have become less tolerant and lenient, particularly in relation to the off the ball and violent incidents in soccer and rugby. Punches in rugby leading to broken jaws have led to convictions for assault.
Off the  ball incidents in soccer  are more likely to lead to convictions for serious assault and imprisonment in the United Kingdom. In Northern Ireland, a 17-year-old was convicted of manslaughter where as a result of a punch, a artery was severed and the victim died.
In professional soccer an Scotland, an international prayer who head butted an opponent causing injury, was sentenced to three months imprisonment. It was stated that the court had no wish to intervene in physical contact sports such as professional football.
It is well aware that contests in physical fitness, strength and agility and some measure of aggression are part of the game for a player and spectator. But when acts are done which go well beyond what can be regarded as normal physical contact, and an assault was committed, the court has a duty to condemn and punish such conduct.
The kicking of a ball or throwing of a coin into a crowd has resulted in prosecutions for assault against soccer players in the United Kingdom. Most infamously, Manchester United player Eric Cantona was convicted of assault where he launched at a member of the crowd who had provoked him while walking off the pitch.