# When Casting Asks You to Improvise: How to Handle Improv in an Audition > When to stay word-perfect and when paraphrasing is welcome, how to improvise around memorized sides without losing the story, what the union rules say about ad-libs, and short drills for actors who have never taken an improv class. - URL: https://www.offbook.com/blog/improv-in-auditions - Published: 2026-10-16 - Last updated: 2026-10-16 You've done the scene as written. It went fine. Then the casting director leans back and says, "Great. Now let's do one where you just play with it. Say whatever comes." If you trained in improv, that's a gift. If you didn't, your brain does something unhelpful: it reaches for the memorized lines, finds them gone, and leaves you standing there with a half-smile. Either way, the question underneath is the same. How much freedom do they actually want, and how do you use it without losing the scene? The short version: figure out which kind of improv the room means, stay word-perfect unless you're clearly invited off the page, and when you are invited, keep the story beats and change only the words. Prepare by learning the scene as a series of actions, not a string of sentences, and practice saying each beat three different ways. ## First, work out which kind of improv they mean "Improvise" covers very different requests, and the right move depends on which one you're in. Most fall into one of these: - A commercial spot with no dialogue at all, where you play the moment with behavior, sounds, and maybe a few words. - Commercial copy that casting calls "loose," where you're told to make it your own and keep the product line intact. - TV or film sides where the director asks for one take with a different feel, but the words stay the same. - A partly improvised show or film, where you get an outline and the dialogue is yours. - A play or devised-theater audition that includes group games or an exercise in the room. Only the second and fourth usually mean "change the words." The third almost never does. If you can't tell which you're in, ask. A [casting director's guide to improv auditions](https://www.backstage.com/magazine/article/improv-audition-tips-12235/) suggests exactly that: if you're not sure improvising is welcome, ask the casting director before you start. ## When to stay word-perfect For most scripted TV, the safest default is the text as written. Casting director Bonnie Gillespie puts it bluntly in her post on [audition ad-libs](https://bonniegillespie.com/audition-ad-libs/): for episodic television you want to stay "100% married to the text," and comedy most of all. One reason she gives is easy to forget. The person who wrote your sides is often a producer on the show, and may not love hearing their lines rewritten. She makes a related point in a piece on [showing them what you'll do on set](https://bonniegillespie.com/show-them-what-youll-do-on-set-in-your-audition/). By the time sides reach you, those pages have survived a lot of rewriting. As she puts it, the pages already have the job; you don't yet. Comedy dialogue is especially fragile. A joke often depends on the exact word that lands last, and a paraphrase that keeps the meaning can still kill the laugh. If you add an "um," a "like," or a "you know" at the front of a line, it isn't a crime, but it's the kind of drift that tells a writer you didn't quite learn it. There are real exceptions. Some shows are built on improvised dialogue. *Curb Your Enthusiasm*, for example, is shot from an outline Larry David writes, and the actors largely improvise their lines. Gillespie also notes that when she casts for improv-friendly filmmakers, she says so in the audition notice. So read the breakdown and the notes. If nothing invites you off the page, stay on it. ## Commercials: where improv is often the job Commercials are the opposite case. One commercial actor argues that [improv training is close to a necessity](https://www.backstage.com/magazine/article/improvisation-training-commercial-audition-necessity-12178/) there, because many commercial auditions have no dialogue and casting often calls in improv-trained actors for unscripted spots. You might be asked to react to the first bite of a sandwich, or to "be the dad whose kid just scored," with nothing on the page at all. On union calls, there's a rule in the background. A SAG-AFTRA commercials tip sheet on [improvising and ad-libbing at auditions](https://www.sagaftra.org/files/tips_tools_-_ad_lib_and_improvs_at_auditions_0_1.pdf), written under the 2013 contract, explains that when a principal performer is asked to devise dialogue, or, in a spot with no dialogue, to devise action the script, storyboard, or direction doesn't give, it counts as an ad-lib or creative session call, which is paid. If you choose to add your own words or actions, that doesn't trigger payment. Contracts change, so check the current one if you're a member. In practice, that may be why you'll often hear "the copy is loose" or "make it your own" instead of "improvise." The casting director's guide adds that since improv isn't supposed to be required on union auditions, you can decline it, and if improv isn't your strength, lead with the script. Non-union calls don't have the rule, but the same courtesy often holds: do the copy first, then play. One thing doesn't change in a loose commercial: the product name and the tagline. Whatever you invent around it, land those words exactly, then add a short [button](https://www.offbook.com/blog/how-to-prepare-for-a-commercial-audition) at the end. ## Improvise around your sides without losing the story When you are invited off the page, the danger isn't that you'll say something wrong. It's that you'll drift away from what the scene is doing. The fix is to learn the scene as a chain of **beats**: what each character is trying to do, line by line, and what changes. Take this short quarrel over a field: > **LOMOV.** ... Oxen Meadows are mine! > > **NATALYA STEPANOVNA.** It’s not true, they’re ours! > > **LOMOV.** Mine! > > **NATALYA STEPANOVNA.** It’s not true! I’ll prove it! I’ll send my mowers out to the Meadows this very day! > > *Anton Chekhov, The Proposal, translated by Julius West (Project Gutenberg)* Written as beats, it's four moves: he claims the land, she denies it, he insists, and she escalates to a threat. If a director said "now go off script," you could change almost all the words, as long as those four moves happen in that order. Skip the escalation and the scene has nowhere to go. Add a fifth move that isn't there, like Natalya suddenly agreeing, and you've broken the story the writer built. So when you improvise around sides, keep three things fixed: - The order of the beats, so the scene still builds the way it's written. - Any specific words the story depends on, such as names, places, the product, or a technical term. - The last line of the scene, or something very close to it, so the reader or director knows where you've ended. The second point comes from Gillespie too. In a post on [sides full of medical jargon](https://bonniegillespie.com/prepping-for-an-audition-with-medical-jargon/), she suggests that if you have to improvise, you reuse the terms from the original sides and improvise the rest. That way, the terms the scene depends on stay accurate. ## The only improv rule you really need: accept the offer Improv teachers have a whole vocabulary, but one idea does most of the work in an audition. Keith Johnstone, in his book *Impro: Improvisation and the Theatre* (1979), describes everything an actor does as an offer that a partner can accept or block. A block is anything that stops the action from developing or cancels what your partner set up. Good improvisers, in his account, accept offers. In an audition, the "partner" is often a reader who's also improvising, or a casting director tossing in a new line to see what you do. If the reader says, "And you brought the dog again?" there is now a dog. Don't say "What dog?" Look down at the dog. Apologize for the dog. That's an accepted offer, and it's what casting is watching for: whether you listen and respond, or wait for your next line. This is also the cure for freezing. You don't need a clever idea. You need to react to the last thing you heard, in character, with the beat you're supposed to be playing. If you keep listening, there's always something to answer. ## Drills for actors who don't do improv You can get much better at this in a few sessions without a class. None of these needs a partner, though one helps. - Write the beats of your sides in the margin, one verb per line ("claims," "denies," "insists," "threatens"). Then do the scene from the verbs alone, with the script face down. - Say each of your lines three ways: as written, in your own everyday words, and in as few words as possible. If you can do all three, you know what the line is doing, not just how it sounds. - Ask what happened ten seconds before the scene starts, and improvise those ten seconds out loud. Walking in already mid-moment makes the first line easier, scripted or not. - For a no-dialogue commercial, pick one specific place and one specific thing to look at, then play thirty seconds of behavior: a reaction, a small sound, a second reaction. Specific almost always reads better than vague. - End every improvised take with a clear finish, a look or a short line, so the room knows you're done and isn't waiting for more. Running the scene with someone feeding you the other lines makes the paraphrase drill far more useful. Offbook can do that: upload your sides, pick your role, and realistic voices read the other characters while Offbook listens through your microphone and plays the next cue when you finish your line. The video below shows line detection, the setting that decides how close to the script you have to be. Choose Auto and drag How exact? to Own words OK for your own-words pass, so a paraphrase still moves the scene on, then drag it to Exact words and run it word for word. Video: [Line detection](https://www.offbook.com/learn/line-detection) (0:57) For a final check, hide your lines in Offbook and run the beats from the cues alone. If you can do the scene both ways, word-perfect and in your own words, you're ready for whatever the room asks. If you want classic scenes to practice the drill on, browse our [public-domain plays](https://www.offbook.com/plays) or use the free [run lines online tool](https://www.offbook.com/tools/run-lines-online), which needs no account. ## If you go blank in the middle Going up during improv feels worse than going up in a scripted scene, because there's no line to find. But the recovery is the same: come back to the beat. Ask yourself what your character wants from the other person right now, and say that, simply. "I want those meadows" is a perfectly good improvised line if it's the beat. If the scene has run its course, finish it. Land the last line from the sides, or a version of it, and hold the moment. A short, committed take beats a long one that wanders. Our guide to [recovering from a messed-up line in an audition](https://www.offbook.com/blog/messed-up-line-in-audition) covers what to do when it happens in the scripted take too. ## Questions actors ask ### Can I change the lines in my sides during an audition? Usually not, unless you're invited to. For episodic TV, especially comedy, casting directors such as Bonnie Gillespie advise staying with the text as written, and film and play auditions generally expect the text unless you're invited off it. Commercial copy described as "loose" is the main exception, and even then the product name and tagline stay exact. ### What do casting directors want when they ask you to improvise? What usually reads well is listening and responding in character, and letting more of your own personality show than the script allowed. You don't need jokes. Keep the scene's beats, accept whatever your reader offers, and finish cleanly. ### Do I have to improvise if I'm asked? Not always. A casting director's guide notes that improv shouldn't be required at union commercial auditions, so you can decline, and if improv isn't your strength, it's fine to lead with the script. If you can, a simple, committed version usually reads better than a flat no. ### How do I prepare for an improv audition if I'm not an improviser? Learn the scene as beats, practice each line in your own words, and rehearse thirty seconds of behavior for a no-dialogue spot. Then run the scene with a partner, or with Offbook reading the other parts, so you practice listening, which is most of what improv is.