Since late 2002, such a ComMod process is being tested in an Akha village of upper northern Thailand to promote collective watershed management, and particularly to examine the interactions between soil and water conservation, agricultural diversification, and social equity. Following a presentation of the context & problem, and of the original characteristics of the ComMod approach, this article describe its concrete use with Akha villagers. The article explains the way a shared representation of the watershed and its dynamics is achieved, and the way it supports collective learning on land management. The flexibility and adaptive characteristics of the gaming and simulation tools used with the people will be highlighted as they fit with the evolving nature of coordination processes in adaptive NRM. Finally, preliminary lessons from this ComMod experiment are presented as well as new perspectives for improving this approach.