The En-ROADS Simulator Reference Guide can be found here. The extensive Reference Guide contains information on the model structure, scope, assumptions, equations, data sources, calibration, and testing. The Reference Guide is a technical document. 

For a more accessible introduction to the model, most users will prefer the En-ROADS User Guide. The User Guide provides background on the dynamics of En-ROADS, tips for using the simulator, general descriptions, real-world examples, slider settings, and model structure notes for the different sliders in En-ROADS.