Revision with unchanged content. In this book, we propose a generic method to develop 2D and 3D multiagent geosimulation of complex behaviors (human behaviors) in geographic environments. Our work aims at solving some problems in the field of computer simulation in general and the field of multiagent simulation. These problems are are: - The absence of methods to develop 2D-3D multiagent simulation of phenomena in geographic environments. - The absence of gathering and analysis techniques that can be used to collect and analyze spatial and non-spatial data to feed the geosimulation models (input data) and to analyze data generated by geosimulations (output data). The main idea of our work is to create a generic method to develop 2D and 3D multiagent geosimulations of phenomena in geographic environments. The main contributions of this book are: - A new method to develop 2D-3D multiagent geosimulations of complex behaviors (human behaviors) in geographic environments. - An illustration of the method using the shopping behavior in a mall as a case study and the Square One mall in Toronto as a case test. - A new survey-based technique to gather spatial and non-spatial data to feed the geosimulation models.