Scarterran martial arts
So how does Scarterran martial arts differ from the martial arts in the real world and various fantasy worlds? Just like in the real world, people have been trying to figure out more efficient ways to kill their enemies since the days of sharp sticks. Scarterrans have the same reasons to fight each other that historical real world humans had. They also have to deal with a much wider array of different sapient mortal races and assorted magical beasts and other fantasy threats to deal with. In the real world, there is a major limiting factor slowing down the societal learning curve of martial arts, and that it is hard to study new ways of killing and maiming people without actually killing and maiming people. One only get so far with advancement through sparring because no one wants to die or be crippled during training. That is why in the real world we are not sure which martial arts style or styles are best for self-defense in life or death situations because no one wants to stab an opponent in the eye or groin in a sparring match. Magical Healing is a game changer. While relatively rare, a master of Healing magic can guarantee any injury short of death can be completely fixed. Even if the damage is reversible, most warriors are not willing to endure the pain of crippling injuries simply to advance the martial arts, but some are. Most magical healers are not willing to use their holy arts to put people back together after brutal experiments, but some are. Also, once a warrior perfects a technique for a gauging someone's eye or doing some other brutal combat maneuver, they don't have to keep doing it. They can teach the techniques to others without the need for magical reconstructive surgery. Beyond this extreme example, Scarterrans rely on the common real world medieval training method of letting warriors wail on each other with blunt weapons. Given that it is relatively simple for a magical healer to heal these sorts of bumps and bruises (or even microfractures in bones) with even a little bit of magical healing warriors can train for longer periods of time and with less need for restraint. The rudimentary power of the Wrath sphere can make any weapon temporarily non-lethal letting people train vigorous with their actual weapons rather than train with inelegant training weapons. The arcane spell, Merciful Weapon allows for this too, though the spell is relatively uncommon. Theoretically, Golems and summoned spirits can help in training too. All this together means that Scarterra, despite being a thousand or more years behind us in most science and technology, would have superior unarmed and melee martial arts to the real world just from brutal application of the scientific method.
Most warriors simply want to learn efficient techniques for killing their enemies and not being killed themselves. They are arguably not true martial artists. It takes a lot of effort to learn a fighting technique from a teacher, but it takes even more effort to pioneer a new fighting style or even a simple technique. Only a tiny number of people work on the development of martial arts for the sake of developing martial arts, but their techniques eventually disseminate down to common warriors. Scarterra has enough war and conflict that if any person or group comes up with a new fighting technique that works, others will want to adopt it if they can. There are lot of different schools or traditions of martial arts but over the centuries there has been a lot of cross polination.
Just about every nation or tribe has lots of people who have weapons and the knowledge to use them. Rulers play a delicate balancing act. A general populace that is too well armed could overthrow those on top but a general populace that is too poorly armed is an inviation to invaders I cover the vagaries of this topic here. Most unarmed martial arts are used in conjuction with traditional weapons based martial training. Young warriors often learn to fight without weapons before they fight with weapons and no soldier wants to be truly helpless when disarmed.
A small number of unarmed martial arts traditions were born from societies that restrict weapon use, forcing people to learn to fight without them. Most soldiers are part time laborers, craftsmen or farmers. The vagaries of daily Scarterran life means they cannot train constantly. The men and women that have the time to live and breathe the marital arts are usually a select warrior class of the nobility or the Nonagon faction. Just like the upper classes and clergy have most of the dragon's share of society's magic users, they also have the dragon's share of the best warriors and they are gate keepers to who learns advanced martial techniques and who does not.