RDDL is the Relational Dynamic Influence Diagram Language, the domain modeling language used in the ICAPS 2011 International Probabilistic Planning Competition. RDDL has been developed to compactly model real-world planning problems that use boolean, multi-valued, integer and continuous variables, unrestricted concurrency, non-fluents, probabilistic independence among complex effects (important for exogenous events), aggregation operators in addition to quantifiers, and partial observability. While RDDL addresses some of the probabilistic modeling limitations of PPDDL, it's deterministic subset also addresses some modeling limitations of PDDL (e.g., models needing nonlinear difference equations or unrestricted concurrency). This tutorial provides a general introduction to RDDL, it's semantics, and a number of detailed examples like elevator and traffic control to demonstrate it's expressive power. It also provides a brief introduction to the rddlsim software that permits the simulation, evaluation, and visualization of planners and planning domains.