Physical self-defense is the use of physical force to counter an immediate threat of violence. Such force can be either armed or unarmed. In either case, the chances of success depend on a large number of parameters, related to the severity of the threat on one hand, but also on the mental and physical preparedness of the defender.
Many styles of martial arts are practiced for self-defense or include self-defense techniques. Some styles train primarily for self-defense, while other martial or combat sports can be effectively applied for self-defense. Some martial arts train how to escape from a knife or gun situation, or how to break away from a punch, while others train how to attack. To provide more practical self-defense, many modern day martial arts schools now use a combination of martial arts styles and techniques, and will often customize self-defense training to suit the participants' lifestyles, occupations, age groups and gender, and physical and mental capabilities.