This paper explores how increasing agricultural productivity through agricultural intensification may influence farmland expansion decisions of smallholder farmers in Ethiopia, Ghana, and Zambia. Six pairs of farmers at each site (72 in total) from different wealth groups were involved in serious games sessions that simulated different institutional, economic, and governance contexts, with players choosing their resource allocation accordingly. The approach was used to explore with farmers, in a ‘safe space’, whether an increase in agricultural productivity and profitability via intensification would reduce or end farmland expansion into natural habitats. The results show that, under certain conditions (such as poor forest governance and lack of alternative income-generating and investment opportunities), agricultural intensification can lead to more agricultural expansion at the expense of natural habitats, such as forests and grasslands. This suggests that intensification strategies to promote increased productivity may need companion strategies to protect forest ecosystems from expansion at the agricultural frontier.