Shrimp aquaculture is economically profitable to coastal people in the Mekong Delta, Vietnam. Nevertheless, conflicts are arising between shrimp and rice farmers from environmental and socioeconomic impacts of shrimp aquaculture. For example, shrimp farming encroaches upon land previously devoted to rice cultivation. This study aims at integrating and sharing knowledge about the rice-shrimp farming system in Bac Lieu Province. Companion modeling (ComMod) was used to involve stakeholders in the construction of a simulation model and discuss its outputs. The first stage of the modeling process consisted of a role-playing game (RPG) in which farmers from two villages in the province recreated their farming decisions. The process revealed diverse water and land-use strategies. In the second stage, agent-based modeling (ABM) used a subset of individual farming decisions to parameterize a generic model of integrated rice-shrimp farming. The initial ABM scenario spatially generated production areas and water salinity patterns similar to the ones used during the RPG sessions. This similarity is expected to convince farmers of the accuracy and value the ABM analysis, and help create continued interest when requested to 'validate' it by providing user feedback on its features and rules. Additional scenarios based on different sluice operators decisions, risk, and economic conditions were collectively simulated and assessed.