Traditional nunchaku is usually practiced in traditional okinawan/japanese martial arts schools, sometimes as a unique discipline, but most often as part of kobudo. Students start by learning the basic techniques (kihon). Then they begin to learn katas. At the same time students develop power in their strikes and accuracy of moves. When a student shows good knowledge of katas (and that may take a few years), he is allowed to start the practice of renzoku-bunkai - a pre-arranged, continuous sequense of blocks & attacks, extracted from kata, but practiced with a real partner who attacks with some weapon, usually a staff (bo). The next step for advanced students is kumite - sparring against an armed apponent. The opponent's weapon may vary from time to time (but, again, usually it's bo). The only students who are allowed to practice kumite are those who have very good control of their weapon, because even a mistake of half an inch can be lethal. In some schools students are also taught how to throw the nunchaku.

In traditional nunchaku training, emphasis is placed on footwork, tai-sabaki (body moves) and blocks. When someone strikes your head with a stick, your expertise in twirling a nunchaku can't help you - you must block your opponent's strike or evade it by moving. Traditional nunchaku techniques are highly effective. They were developed for combat and if they are practiced in realistic manner, these techniques allow the martial artist to resist an assaulter who is armed with a stick or knife. What about any weak points of traditional training? One limitation which exists in some schools is that tradition is adhered to religiously and any attempt to change or to add something is considered heresy. A second weak point is the period of learning - it takes a long time and much study to master nunchaku techniques. During the few first months (or years!), before the student has mastered some combat skills, he is relatively defenseless. That can be very bad for those who need to learn self-defence relatively quickly.

In the early 80's, Kevin D. Orcutt, an American police sergeant, holder of a black belt in Jukado, developed the OPN (Orcutt Police Nunchaku) system, intended for police needs. It uses specially build plastic nunchaku instead of the usual police baton (nightstick) or the PR-24 (side-handle baton) as a primary control device for situations when the usage of a gun is unjustified. The arguments in the plastic nunchaku's favour are its small size (12 inches), which makes it easier to conceal, and to carry comfortably; its "ease-of-use", and the ability to apply various non-lethal but effective techniques. There had been previous attempts to use nunchaku for police work, but OPN is the first system which is based on control and not on impact techniques. As Kevin Orcutt reports, more than 200 law enforcement agencies in the USA use his system.

The OPN system teaches a limited number of simple techniques which can be learned during a short training period. In this system, nunchaku is mainly used for control during arrest or for self-defence against an empty-hand attacker... a gun is used against an armed attacker. The OPN system include various techniques for arrest and control: pain grabs/joint locks, takedowns, "come-along" techniques, techniques for handcuffing, blocks against punches and kicks (which may become a grab-control technique), and a few strikes (which may be used only as a last resort). Any situation which allows striking with the nunchaku, probably also allows the usage of a gun. From the point of view of the martial artist, those few hours of training (instructors typically receive 32-hour courses, then teach 16-hour courses) would only be the barest beginning, but from the policeman's point of view, 16-hours of training is sufficient to do the job. It's hard to compare OPN with other nunchaku systems because of it's special status, but the fact that OPN has been used in real fights for more than 15 years clearly demonstrates it's effectiveness.

At the beginning of the 1990's, a new sport - Nunchaku-Do - was created in the Netherlands. As with many other martial arts which have been converted to a sport (e.g. boxing, fencing or spear-throwing), this art lost most of its "martial" aspect. This sport includes three competition divisions - kata, kumite and free-style. In most of schools, self-defence or nunchaku-jutsu are also taught.

Kata are pre-defined combinations of techniques which have to be done as perfectly as possible. During the learning process, especially-created katas helps students to practise all the techniques required for a particular belt level. Within this discipline there is also a contest regulation. Competitors are judged on speed, technique and style.

Kumite means a single combat fight. This discipline has a lot in common with fencing. Two fighters, armed with safety foam-padded nunchaku and protected by headguards, try to score 6 points by striking the other with a nunchaku. You can only score after you've blocked an attempted score of the other, or after you've made at least two techniques (the nunchaku changed hands two times). Each strike which hits the opponent earns the fighter 1 point. Difficult and effective strikes (e.g. strike to the head) earns the fighter 2 points. Hits are not allowed below the knee, in the groin, on the back and on the throat. Also not allowed are: punches and kicks, grappling, holding both handles of the nunchaku in one hand, and thrusting the opponent with both handles. As you can see, there too many limitations to allow this sport to be an effective martial art.

Free-style - is an exercise performed to music where the competitors are free to use any kind of technique, both with a single nunchaku or two at the same time. This discipline has a lot in common with callisthenics or juggling; that is, virtuoso performances and incredable moves, which may be impractical, but which look good. Within this discipline there is also a contest regulation. Here the competitors are judged on originality, style and technique.

The Self-Defence or Nunchaku-Jutsu is the most "martial" division of Nunchaku-Do. Within this discipline, students learn to defence themself using nunchaku against different kinds of attack - both armed and unarmed. Students are not only required to be able to strike with the nunchaku but also to defend themselves in a controlled way, using blocks, joint locks, takedowns and disarming. There are no competitions in this division, but the test of nunchaku-jutsu techniques is a part of the black belt examination from 1st dan and higher.