This seminar proposes to explore the methodology of use-wear analysis based on the weapons from La Tène, the site that gave its name to the Second Iron Age, developed by the author. This method makes it possible to distinguish traces of destruction linked to martial use, i.e. produced fortuitously/accidentally in the context of fighting (at war, during battles) and traces of destruction occurring during voluntary mutilation rituals (a frequent phenomenon in the Gallic context). The contribution of various disciplines not usually used in protohistory - experimental archaeology, forensic sciences, biomechanics, ethnoarchaeology, materials engineering, applied mathematics, anthropology, forensic medicine and battlefield archaeology -, the development of an adapted terminology and the consideration of restoration processes bring to light new evidence on the martial techniques of the ancient Celts and allow a better understanding of the Celtic art of war. We propose here to present some of the results.