Fuzzy controllers are a popular method for animated character perception and control. A drawback of fuzzy systems is that time intensive manual calibration of system parameters is required. We introduce a new Genetic-Fuzzy System (GFS) that automates the tuning process of rules for animated character steering. An advantage of our GFS is that it is able to adapt the rules for steering behaviour during run time. We explore the parameter space of the new GFS, and discuss how the GFS can be implemented to run as a background process during normal execution of a simulation. Copyright © 2010 John Wiley & Sons, Ltd.