Tricking is defined as a combination of gymnastics, martial arts and Capoeira all performed in single movements or combinations to be aesthetically pleasing rather than effective in a fighting situation.
There is some crossover between tricking movements and those seen in free running, but essentially they are different disciplines. Tricking is expected to be practised on a flat surface (such as a plyo floor), whereas free running focuses on making use of obstacles and the environment. It is a common misconception that tricking is just the flips part of free running, when it's in fact a completely separate discipline, incorporating many martial arts movements such like kicks which are rarely seen in free running.
 About tricking
As Tricking is a relatively new and underground sport, you will be lucky to find a fellow tricker in your town or neighbourhood. Because of this, there are several online communities in the form of message boards to bring the international tricking scene together uniting trickers from all backgrounds and areas, the biggest of which have thousands of members. You can discuss tricking, read up articles written by other members, share your videos for feedback from other members and most importantly arrange meetings or ‘gatherings’ for you to meet other trickers that live nearby. Often, because of the distance some trickers are apart from each other, these gatherings are held over several days. Some gatherings are very unorganised and basic, however there are others, such as the Loopkicks gathering, which is considered by many to be the best annual tricking gathering in the world, run by a top tricking team. Loopkicks, like some other up and coming tricking teams, trick for a living and do not have any other jobs to support them.
The actual techniques in tricking are very unique, however, because of the gymnastic elements in Tricking, there are a lot of move copied directly from gymnastics (such as the backflip), but there are many others unique to tricking, such as the "boxcutter", which consists of a 540 degree vertical spin to land on the leading leg and ending with a large outside creasent kick from the non landing leg. There are over 1000 tricks altogether and all of them have been categorized into a tricking book called the ‘Tricking Bible’ by a well known tricker called Sesshoumaru.
Tricking (not to be confused with free running or parkour) is all performed on a flat surface, never off height or on trampolines. Unlike Freerunning or Parkour, Tricking is actively discouraged to be practiced on concrete or hard ground due to unnecessary risk of injury, as Tricking is about linking tricks together in a combo, rather than about the single movement seen in Freerunning and Parkour. Because of this, trickers often train on plyo or grass.
Tricking is a fairly new sport developed from competitors in freestyle form competitions in Karate circuits, the NASKA (North American Sport Karate Association) across America. Originally the form competitions (forms are a set combination of movement) were just from classic forms which were originally created thousands of years ago as a method to pass down techniques from generation to generation before the times of videos or accurate drawing methods. These set movement forms were designed to be performed with perfect form and varying speeds so a lot of the judging is towards technique. People more interested in extreme sports decided to create a new style of form competitions which involved less traditional movements and more acrobatics and eye pleasing movements than those that are actually part of Karate.
This soon evolved into a sport called Tricking although without the judges - creative form competitions were judged that the creative form competitions had Tricking can be performed anywhere from backyards to football fields, some prefer the safe environment of gymnastics centres where they can use protective crash mats to soften their falls when trying more difficult movements.
Because the roots of Tricking are in martial arts the kicking side of it is where most of the weight is put, original competitors in the NASKA circuit such as Manny Brown, Chris Devera and Steve Terada all try to keep the Tricking scene as close to its martial art roots as possible and stress other trickers to use kicking tricks as much as possible.