The Lam Dome Yai watershed is a drought-prone area dominated by the rainfed lowland rice (RLR) ecosystem. It is also a homeland of the poor and the only recourse for better livelihood is to migrate to cities. Poverty and labour migration are a result of the interaction between agro-ecological constraints such as erratic rainfall distribution, lack of irrigation and poor soil quality, and socioeconomic dimensions such as economic disparity. In this research, decision-making process of stakeholders regarding farm and labour management is a key to better understand such interaction. A participatory modeling approach like Companion Modeling (ComMod) can be used to understand stakehoders' decision-making process and acquire the mutual recognition of different points of view on a given problem to build a comprehensive knowledge. It is very important to take this knowledge into account for successful investments when the sustainable livelihood of this local community is targeted. In this experiment, we aim at modeling the interaction between land/water use and labour management on different types of RLR farms. The results of three successive participatory modeling workshops using combined-tool, Role-Playing Game (RPG) and Multi-Agent Systems (MAS) model, are presented. The results indicate that the diversity of farms plays an important role to alleviate the labour scarcity. An improvement of water availability is likely to affect only small holders in terms of more farm intensification and fewer migrants. The perception of water availability in farmponds and the use of water are different based on rainfall situation and farmer's means of production. However, a similar rice-growing practice emerged as a collective agreement among players when a community pond was introduced into the RPG.