1. This paper presents solutions for one requirement of autonomous characters in animation and games: the ability to navigate around their world in a life-like and improvisational manner. Steering behaviors are largely independent of the particulars of the character's means of locomotion. Combinations of steering behaviors can be used to achieve higher level goals. 2. Autonomous characters represent a character in a story or game and have some ability to improvise their actions. This stands in contrast both to a character in an animated film, whose actions are scripted in advance, and to an "avatar" in a game or virtual reality, whose actions are directed in real time by a human player or participant. In games, autonomous characters are sometimes called non-player characters. 3. The behavior of an autonomous character can be divided it into 3 layers: action selection, steering and locomotion. 4. The steering level decomposes the goal into a series of simple subgoals, and must anticipate the future, and take into account eventual consequences of current actions. 5. The individual steering behaviors serve as building blocks for more complex patterns of behavior. Combining behaviors can happen in two ways. A character may sequentially switch between behavioral modes as circumstances change in its world. On the other hand, some kinds of behaviors are commonly blended together, effectively acting in parallel.