This workshop will be an introduction to building probabilistic system dynamic models using GoldSim. GoldSim differs from traditional system dynamics software in that 1) it puts much greater emphasis on probabilistic simulation techniques to support representation of uncertain and/or stochastic systems; and 2) it relies on more specialized model objects (beyond stocks, flows and converters) in order to make models less abstract (and hence more transparent) and help represent processes and events that cannot easily be represented using a traditional system dynamics approach. In general, this is because GoldSim has traditionally been used for engineering and scientific applications where quantitative probabilistic predictions of future performance have been required (e.g., by regulators) in order to inform and defend policy and design designs. The workshop is intended for people who are already familiar with traditional system dynamics tools, and will focus on how GoldSim models can be used to complement and extend models built using traditional approaches. The session will demonstrate basic GoldSim functionality, how GoldSim can be used to represent uncertain and stochastic systems, and will discuss a number of specialized objects provided by the software. Computers are not required for this short workshop.