Without well-constrained grammars and lexicons to support it, a great design isn’t worth the paper it’s printed on. What types of concerns should be taken into consideration when designing complex grammars? What are some characteristics of a complex grammar task? What grammar features can be leveraged to optimize recognition? This session begins with a very high-level refresher on GRXML grammar structure and then delves into advanced topics in how to optimize recognition for a variety of complex tasks. We discuss what makes these tasks complex and, in each case, some how-to methodologies for optimizing recognition given the task.