When to Keep an Improvised Line

Many lines that audiences remember were not in the script. An actor adds a phrase during a take, a joke after the director calls cut becomes part of the scene, or a speech grows over several takes into something longer than what was written.

Improvisation produces material. It does not decide whether that material belongs in the film. These eight commentaries describe both stages: how directors used improvisation, and how they decided what to keep. The decision usually depended on whether the new material served the scene’s purpose, not on whether it was good.

§1 Improvise to build the characters

Some improvisation never appears on screen. Francis Ford Coppola describes a day during preparation for The Godfather Part II when the cast moved between the family’s houses on the estate set, improvising ordinary scenes about business and children.

The purpose was to give the actors shared experience in the characters’ home before the scripted scenes were shot. Coppola compares it to the family dinner he staged before the first film.

This kind of improvisation is closer to rehearsal. It shapes how the actors behave in the written scenes rather than adding lines to them.

§2 Keep a line when it adds to the character

Other improvisations end up in the film because they show something the script did not. Ridley Scott describes Anthony Hopkins’s additions to Hannibal Lecter.

A casual phrase from a character the audience knows to be a killer does more than add humor. Scott’s point is that the contrast makes Lecter more threatening, which is a reason to keep a line that was never written.

Barry Sonnenfeld describes a different purpose in Men in Black II. He wanted the audience to understand quickly that two characters were drawn to each other.

The ad-libbed exchange did a job the scene needed: it established a relationship in a few seconds without exposition.

§3 Watch for material outside the take

Useful lines do not always come during a take. In the Mission: Impossible - Fallout commentary, the filmmakers describe a line Michelle Monaghan said as a joke after the camera stopped.

Hearing that the line was good was the first step. The second was writing it into the scene so it could be filmed properly. Material found between takes is still available if someone is listening for it and has time to shoot it again.

§4 Cut a line when it works against the film

The clearest case for removing a successful improvisation comes from The Way of the Gun. Ryan Phillippe improvised a line in a scene leading up to a shootout, and it drew a laugh at a test screening.

The line worked as a joke, and that was the problem. The film’s approach required violence to carry consequences. An audience laughing at that moment was reacting against what the scene was meant to do, so the line was removed.

The Usual Suspects commentary describes the same judgment at a larger scale.

An hour of strong improvised material did not reach the film because it did not serve the film as a whole. The test for improvised material is the same as for scripted material: does it help this scene do its job?

§5 Let the result settle a disagreement

Collaborators can disagree about whether improvised material works before anyone has seen it edited. Matthew Vaughn describes such a disagreement with screenwriter Jane Goldman on Kick-Ass.

Vaughn shot the material, and the finished scene answered the question. Improvisation is hard to judge in advance because its value depends on performance and timing. Filming it and reviewing it in the edit can be quicker than arguing about it on set.

§6 Shape improvised material in the edit

Improvisation also changes the editor’s work. Sonnenfeld describes a speech in Men in Black II that grew through ad-libbing.

The final speech does not exist in any single take. It was assembled from the best moments across many. Shots from behind the actor allowed new lines to be added without matching lip movement.

An ad-lib can also become an editing point. The Return of the King commentary describes how a line improvised by John Rhys-Davies led into a new cut.

The line was useful because of what could follow it. It gave the filmmakers a quick transition into the next sequence, different from how they had first conceived it.

§7 Questions for improvised material

These accounts suggest five questions:

1. Is the improvisation for the actors or for the film? Coppola’s day on the Godfather Part II set built the characters without adding a single line to the film.
2. What does the line show about the character? Hopkins’s additions in Hannibal made Lecter more threatening, and the Men in Black II exchange established a relationship quickly.
3. Is anyone listening between takes? The Fallout line came after the director called cut.
4. Does the reaction match the scene’s purpose? The Way of the Gun removed a line because the laugh it got worked against the film.
5. How will it be edited? Ad-libbed takes in Men in Black II and Return of the King were shaped and placed in the cutting room.

Improvisation gives a film more options. Each one still has to pass the same test as the script: whether it helps the scene and the film do what they are meant to do.