The Hoabinhian represents an iconic pebble facies associated with the tropical forest regions of Southeast Asia, dating from the end of the Upper Pleistocene to the middle of the Holocene. In a region distinguished by the existence of multiple human populations, it emerges and then vanishes when only modern humans remain. This technical phenomenon is defined by the crafting of weighty, thick tools from pebbles, including unifaces, choppers, chopping tools, and splits, with bifacial pieces appearing less frequently. Notably absent from this last Paleolithic hunter-gatherer-forager toolkit are armatures, projectiles, or arrowheads. Therefore, in Southeast Asia, there seems to be a lack of technical evolution in lithic industries and no archaeological evidence of hunting projectiles from 40,000 to 4000 BP. This positions the Hoabinhian pebble tools as a part of the broader question concerning human adaptation, specifically technical behavior, forest subsistence, and life in the tropics. Compared to the contemporary Upper Palaeolithic in the West, these pebble industries might seem to exhibit technical-temporal inertia without significant change, or even a cognitive regression. However, without invoking any eco-geographical determinism, we find ourselves examining a unique and radical technical choice that originated in the forest, representing a dialogue between technology and the tropical environment. The Hoabinhian case is a phenomenon that signifies a balance between the mineral world and a specific plant, namely bamboo. The archaeological invisibility of lithic material (like pointed weapons and armatures) is logically offset by plant material, sometimes siliceous like bamboo. The Hoabinhian technique represents a novel complexity and modernity that only modern Homo sapiens has managed to invent. The persistence of this technical phenomenon in a humid tropical context, associated with perishable materials, contrasts sharply with the conventional prehistoric narrative of the Western world. By using examples taken from Hoabinhian material uncovered during recent excavations in the Laang Spean cave in Cambodia by the MEAE's “Mission Préhistorique Franco-Cambodgienne”, we aim to illustrate the originality and diversity of lithic reduction sequences on pebbles. We will also propose functional hypotheses for these pebbles using a structural approach based on 3D modeling.