iPlan is a free online game that allows players to construct, investigate, and solve simulated urban and regional planning problems. Suitable for use on smart phones, tablets, chromebooks, and laptops, iPlan allows players to explore the environmental and socioeconomic impacts of land-use decisions in their own local contexts. The system uses geospatial data, ecological and economic models, and optimization routines to transform any location in the contiguous United States into an interactive land-use planning simulation. Players construct rezoning plans that address socioeconomic and environmental issues, and their plans are evaluated by virtual stakeholders who advocate for different community priorities. iPlan thus provides a platform for exploring complex land-use issues nationwide.