Symbolic Actions and Symbolic Objects, John Truby, The Anatomy of Story, p. 239 —
A single action is normally part of a larger sequence of actions that comprise the plot. Each action is a kind of car in the long train of the hero and opponent competing for the goal. When you make an action symbolic, you connect it to another action or object and so give it charged meaning. Notice that making an action symbolic makes it stand out from the plot sequence. It calls attention to itself, in effect saying, “This action is especially important, and it expresses the theme or character of the story in miniature.” So be careful how you use it.
Symbolic objects almost never exist alone in a story because alone they have almost no ability to refer to something else. A web of objects, related by some kind of guiding principle, can form a deep, complex pattern of meaning, usually in support of the theme.
When creating a web of symbolic objects, begin by going back to the designing principle of the story. This is the glue that turns a collection of individual objects into a cluster. Each object then not only refers to another object but also refers to an connects with the other symbolic objects in the story.
You can create a web of symbolic objects in any story, but they are easiest to see in certain story forms, especially myth, horror, and Western. These genres have been written so many times that they have been honed to perfection. That includes objects that have been used so often that they have become recognizable metaphors. They are prefabricated symbols whose meaning the audience understands immediately at some level of conscious thought.