Hand-to-Hand combat in Avergene has a long history. In a world where cities and populations have lived somewhat stable for thousands of years the development of fighting styles is quite elaborate.
The study of warfare and the focus on self defense often take the practitioners into different directions. However, the end result of the study of fighting is a set of disciplines and practice of specific mental practices and physical actions.
In Hero System those mental practices can take effect in limitless ways. The implementation of these is something that the campaign GM and player would need to investigate together as part of the Character Creation process.
For the physical maneuvers Hero System includes a system of combat attack and defense maneuvers that can be purchased as skills. The specific maneuvers a character learns will likely be based on the description of the martial art they study and often these maneuvers are similar between all practitioners of the martial art.
There are a variety of Feats that are special to unarmed combat. There feats cannot be used with any combat involving a weapon.