Think of the rose petals in American Beauty, the bird imagery in Shawshank Redemption or Leon's beloved houseplant in The Professional.

These metaphors stay with us long after the movie. Like the sled in Citizen Kane, they work as visual synopses, remembered for their story content and emotional power. Often featured on movie posters, metaphors arrest us, instantly messaging a story idea in a single image.

Extended metaphors, those that run alongside a character or plotline, can carry a great deal of the story load. They can enter a scene with stealth or a loud bang. They have an elasticity that allows the writer to add a layer of signifying pictures that is closest in analogy to laying a track of visual music.

Two Kinds of Metaphors

Most screenplays use two kinds of metaphors. I'll call the first kind static and second kind dynamic.

A static metaphor is a metaphor whose meaning is obvious and constant like using red to signify sexuality. It usually reflects one characteristic and one character. It doesn't get tangled in other elements of the story. When static, its dramatic value is limited.

A dynamic metaphor is one that is mapped out much like a plotline. It has a beginning, middle and end. Its meaning is clearly established in its first use and provides new information as the movie continues. It is often entangled with other characters and/or found in new situations or locations. In fact, its messaging potential is precisely because multiple characters interact with it, it's juxtaposed against different ideas, and appears throughout the movie.

A dynamic metaphor may be represented by any number of objects. It might be portable, stationary, a wardrobe item or a prop. Regardless, each time another character interacts with it, we learn something about that character with respect to the metaphor, but also as compared to other characters in the film.

What is especially useful is how well a dynamic metaphor can externalize the interior world of a character. This is because in interacting with the metaphor, the character is unaware of what is being revealed. This provides a kind of psychological truth that is arresting for the "pureness" of the character reveal it produces.

Metaphors have plotlines. They don't happen accidentally, but are planted, consciously constructed just like the action and dialogue that they run alongside.

Here are two examples of the dynamic metaphor in use. These are taken from two classic American films: Out of Africa and Bound. What's important in both examples is how deftly they convey abstract ideas and indicate transformation wordlessly. In each case they create a character continuum that externalizes the changing internal world of its characters.

The first example is from Sidney Pollack's Oscar winning film, Out of Africa based on the novel of Isak Dinesen and written by Kurt Luedtke.

Movie: Out of Africa

Metaphor: White Servant Gloves

First Use:

In Act 1, Protagonist Karen Blixen arrives in Kenya in 1913. She settles on a farm in the middle of nowhere. One of her first acts is to place white servant gloves on the Kikuyu "houseboy," a young native Kenyan, she has just hired. Writer Kurt Luedtke has this happen on page 27.

The gloves externalize Karen's central conflict with herself, environment and her American born lover, Denys. Karen has just married for an aristocratic title and now attempts to bring European aristocratic trappings to her farm in Africa.

The gap between Karen and her environment, is demonstrated by the houseboy who holds his hands mid-air staring at the gloves like alien objects.

Second Use:

In Act 2, Karen's lover Denys is at dinner. Denys laughs, responding negatively to seeing the houseboy awkwardly serve dinner wearing the white gloves. This scene underscores the difference between Denys and Karen in how they view the Kikuyu and the value of European social norms. Despite the challenge to her values, Karen persists with the white gloves, indicating she is still an outsider to Africa.

Final Use:

In the final scenes of the movie, we learn two important things about Karen. The first is that she must leave because her farm has brought financial ruin. The second is that through her working alongside the Kikuyu, she has changed.

To indicate this change writer Luedtke returns to the metaphor of the gloves. This time the job of the gloves is to show Karen's character transformation. Karen removes the houseboy's gloves saying, "I should have done this a long time ago." Even though Karen has failed financially, her removing the gloves indicate she has succeeded internally. She has rejected her aristocratic ideals, and adopted the egalitarian values represented by Denys.

Analysis

The power of the gloves in this movie would have been very limited if used only once. What made them work is that we saw them throughout the movie. The first time they represent the values Karen arrives with. The second time they signify the gap between her values and Denys'. The final time they indicate Karen's change, as she removes them.

The challenge for the writer is not to throw away the opportunity of continuing the use of what could be a useable metaphor, in this case represented by a wardrobe item. Often it is easier to create an entirely new scene with new objects and new locations. However, repurposing a signifying object and extending a one-time use to a dynamic metaphor can add a layer of storytelling to deepen character.

The most important requirement for the effective use of a dynamic metaphor is to clearly establish its meaning when it first appears. This is usually in Act 1. In the same way a character's "normalcy" is established in Act 1, a metaphor needs to be set up cleanly, with a precise meaning or "baseline." If the writer consciously constructs the metaphor plotline, he or she has a powerful tool.

In the next example of a dynamic metaphor at use, the writer uses a single prop. Props, like wardrobe, live alongside the characters in a movie. Writers can leave them silent, or use them to illuminate character.

In the Wachowskis' brilliant mob-noir, we see a pair of garden clippers used to indicate where we are in the movie and who is on top. Here is an example of a dynamic metaphor at work in Bound.

Movie: Bound

Metaphor: Garden Clippers

First Use:

The first time the garden clippers are used in Act 1, it is when a mid-level mobster, Caesar, watches his boss apply them to a crooked accountant. Each time the accountant fails to give the right answer, the boss snaps off a finger. The garden clippers indicate the hierarchy of power. They also link power with brutality. When Caesar later tells his wife about the dismemberment, Caesar is in awe of his boss's brutality.

Second Use:

In Act 2 much has changed. Caesar now suspects his wife is crooked like the accountant. Caesar believes she and her girlfriend have betrayed him. Caesar now adopts his boss's methods and threatens the betrayers with the same pair of garden clippers.

Here the use of the clippers indicates that Caesar has achieved the same level as his boss whom he admires. He can completely shutdown all human feeling, even for his wife. This scene establishes just how "bad the bad guy is" which heightens our fear and sympathy for his wife, the film's protagonist.

Final Use:

In Act 3 Caesar is now in a full-out battle to the death. He has his wife's girlfriend tied up in a closet. And despite the fact that he has killed a mob boss and his son, it looks like Caesar is going to win. Just when it looks like all is lost, his wife's girlfriend, Corky, spots the garden clippers in the closet, and frees herself.

As soon as Corky picks up the garden clippers they ably indicate a shift of power. In the hands of the antagonists the clippers represented brutality, but in the hands of protagonist they mean freedom and justice.

Analysis

In both Out of Africa and Bound, the metaphor appeared three times. In each film it appeared once in each act, and played a significant role in a pivotal scene. Each time we immediately understood the final meaning because the metaphor had been so well set up in Act 1.

It is very easy to populate scenes with entirely new elements. It is much more difficult to repurpose the elements from an earlier scene. This takes ingenuity, but the payoff is that audience can begin to compare and more actively engage in decoding the story's meaning. Caesar's victim could have just easily found a cell phone in the closet as garden clippers, but the clippers are more powerful. Their repetition has dramatic value.

The repetition trains the audience to believe that whoever holds the clippers holds the power. Consequently, as soon as Caesar's victim, Corky, spots the clippers, we know there is a reasonable hope that she is going to escape. We let ourselves believe this because we know they have a symbolic meaning in addition to their functional one.

Good metaphors usually emerge naturally from the story. It is an organic process that writers often don't finalize until they have stabilized the plot and gone a couple of drafts. Once a good metaphor is found, it is useful to map it out much like an action plotline. Too many can clutter a good story, but a few powerful metaphors can deepen the movie going experience and give shadings to a character that are difficult to achieve in other ways.

Think Rosebud.