Muay Chaiya is a traditional style of Thai Boxing from the region of Chaiya. It makes use of punches, elbows, kicks and knees, but also grappling, throws, articular keys, and ground work. Tum Tap Chap Hak is a group of techniques where Tum Tap refers to throwing and controlling to the ground and Chap Hak refers to grabbing and breaking limbs.

Fighting against a Muay Chaiya fighter is often compared to fighting against a durian (an asian fruit with spikes and hard skin): through the use of the hardest parts of its body, a Chaiya practitioner damages the weapons of his opponents one after another and then proceeds to counter with the maximum efficacy.

Muay Chaiya was developed before the introduction of the sport style, what is now well known as Muay Thai or Thai Boxing. At that time there were few to no limitations to the techniques and damages that could be inflicted to opponents, fights often terminated with the death of one of the competitors. For this reason there are almost no sportive competitions nowadays (with only few regulated exceptions eg: Naksu tournaments), while the toughness of the style can be effectively applied for self-defence and is still taught in Thailand and abroad to martial artists that want to deepen their knowledge or people that want to learn how to defend themselves in case of danger.

The term Boran in Thai language means old, ancient, traditional. Muay Boran is an ombrella name for many different Muay styles originated in different areas of Thailand, often named after the area of origin; the main Muay Boran styles are Muay Chaiya, Muay Thasao, Muay Korat and Muay Lopburi.