This document provides an introduction to PharmaSim, a marketing simulation. It outlines the purposes of PharmaSim as understanding marketing planning processes and learning through practical application. It describes the PharmaSim environment, which simulates the US OTC cold medicine market in the early 1990s. Five competing companies and their brands are listed, along with basic consumer needs, product attributes, consumer behaviors, segmentation approaches, distribution channels to consider, and preliminary questions for analysis.