The problem in Figure 1.6b might remind you of a video game. In the arcade classic Pacman, the ghosts are programmed to seek the player. Modern video games involve human-like characters that exhibit much more sophisticated behavior. Planning algorithms can enable game developers to program character behaviors at a higher level, with the expectation that the character can determine on its own how to move in an intelligent way.
At present there is a large separation between the planning-algorithm and video-game communities. Some developers of planning algorithms are recently considering more of the particular concerns that are important in video games. Video-game developers have to invest too much energy at present to adapt existing techniques to their problems. For recent books that are geared for game developers, see [152,371].