Sometimes actors want to have a say in the words they're given; sometimes they want to stretch their artistic muscles; sometimes they look at the scripts they have to do and think, "I could do better than this!" When this happens, and the producers are on their side (or the network is), you have something written by a cast member.
Much less prevalent than Directed by Cast Member, particularly in these days of arc-driven television. Writing is less glamorous than directing, for one thing, and it's harder to develop a story from scratch than to bring someone else's to the screen.
Key to both of these tropes is that the actor gets into writing or directing through the show they're on, without having a previous background in it (let alone being the series creator). For the opposite direction of crossover, see Descended Creator and Creator Cameo. For shows where the cast and the writing staff heavily overlap, see Cast Full of Writers.
Examples:
- Ian Marter, who played Dr. Harry Sullivan in Doctor Who, subsequently wrote several of the Doctor Who Novelisations, as well as an entirely original novel featuring Harry as protagonist.
- Has happened a few times in the Star Trek franchise:
- Andrew Robinson, who played Elim Garak in Star Trek: Deep Space Nine, wrote a spin-off novel, A Stitch In Time, centering on the character.
- William Shatner, who played Captain Kirk, co-wrote a series of novels known as the "Shatnerverse", which take place in an Alternate Timeline in which Kirk is resurrected after his main-canon death in Star Trek: Generations.
- Paul Darrow, who played Avon in Blake's 7, wrote an officially-licenced spin-off novel, Avon: A Terrible Aspect, which gives his own preferred version of his character's pre-show backstory.
- Christopher Reeve was offered credited story input to entice him back for Superman IV: The Quest for Peace. The title and anti-nuclear theme were his, and he won a lawsuit against a writing duo who claimed otherwise.
- Matt Damon and Ben Affleck both starred in and wrote Good Will Hunting. They won an Oscar for the screenplay.
- The Devil's Hairpin was written and directed by Cornel Wilde who also is the main star. Wilde also wrote a song called 'Swing It Just a Little More' for the soundtrack alongside Ross Bagdasarian who also wrote 'The Touch of Love' for the soundtrack as well.
- Charles Laughton hated the Dalton Trumbo-written dialogue he was initially given in Spartacus, so Peter Ustinov rewrote all of the scenes featuring the two of them, which placated Laughton enough to complete his portion of the film.
- The Blood and Ice Cream Trilogy are all co-written by star Simon Pegg.
- Star Trek
- Leonard Nimoy helped develop the fourth and sixth Star Trek films, and like Reeve, had the writers of an unused script try to muscle him out of the latter credit. (Coincidentally, they were the legitimate screenwriters of Superman IV.) A lawyer-negotiated compromise saw Nimoy share story credit with the pair.
- Star Trek V: The Final Frontier was based on a story by William Shatner. His original outline was titled An Act of Love.
- Brent Spiner received co-story credit for Star Trek: Nemesis.
- Simon Pegg and Doug Jung co-wrote Star Trek Beyond and played Scotty and Sulu's husband, Ben, respectively.
- I Want Someone To Eat Cheese With was written by, and stars, Jeff Garlin.
- Eddie Murphy has written stories for Coming to America, Beverly Hills Cop II, Boomerang, and Vampire in Brooklyn. He has written screenplays for Harlem Nights and Norbit.
- Will Smith wrote the story for After Earth.
- Seth Rogen co-wrote Superbad, The Green Hornet, This Is the End and co-wrote the story for The Interview.
- John Cusack co-wrote Grosse Pointe Blank, High Fidelity and War, Inc..
- Edward Norton reworked extensively the script for The Incredible Hulk, but the Writer's Guild denied him credit.
- Carl Gottlieb, who plays newspaper editor Meadows in Jaws, is also responsible for the shooting script - ironically, Meadows wound up getting less screentime with each script rewriting.
- Amy Schumer wrote Trainwreck.
- Kurt Russell co-wrote Escape from L.A.. The ending was his idea.
- Richard O'Brien wrote The Rocky Horror Picture Show and its sequel Shock Treatment, in which he played Riff Raff and Cosmo.
- Emma Thompson wrote the screenplay for Sense and Sensibility, and starred as Elinor Dashwood.
- Chris Noth received co-story credit for Exiled: A Law & Order Movie, the Made-for-TV Law & Order movie that brought his character back from a three-year bus trip.
- An unusual example exists in the case of Doctor Who Meets Scratchman, which was written by co-stars Tom Baker and Ian Marter but was ultimately never picked up for production. Had it actually been produced and released, it would've been an eclectic, Terry Gilliam-esque game of cat-and-mouse through time and space between the Doctor & company and Satan (named "Scratchman" for whatever reason) that would've culminated in a final battle on a giant pinball table. The script was finally realized as a novel by Baker (alongside James Goss - Marter having sadly passed away in the 90s) in 2019
- Paul Rudd co-wrote Ant-Man and the Wasp.
- Small Wonder had a few episodes written, at least in part, by Dick Christie.
- Sonia Manzano has played Maria on Sesame Street since 1971, and has written for the show since 1981.
- During their days on Head of the Class, Brian Robbins and Dan Schneider had their first writing credits on the "Will The Real Arvid Engen Please Stand Up?" episode. And the rest is history.
- Brian Krause (Leo) is the only cast member of Charmed to co-write an episode: he has co-story credit on "Sense And Sense Ability." He's said the finished product was different from what he turned in.
- Unlike Directed by Cast Member, very few episodes of the Star Trek franchise qualify - in fact, the only ones are DS9's "The Muse" (co-written by Majel Barrett-Roddenberry) and Voyager's "Life Line" (co-written by Robert Picardo). Both focused on those actors' characters. (Walter Koenig wrote "The Infinite Vulcan" for the animated series, but due to budget limitations, wasn't a cast member on that show.)
- Barry Watson wrote an episode of 7th Heaven (not one of the two he directed).
- Robert Culp loved doing this on his shows: Trackdown, I Spy, and The Greatest American Hero all had episodes he wrote (AND directed). In addition, he wrote one of the two episodes of Cain's Hundred on which he guest-starred (strangely averted with The Rifleman - he guest-starred on two episodes and also wrote a two-parter in which he does not appear!).
- John Schneider co-wrote and directed "Opening Night At The Boar's Nest," the Series Finale of The Dukes of Hazzard.
- In addition to being the only person to appear in every episode of M*A*S*H, Alan Alda also wrote numerous episodes (and was one of the writers of the Series Finale to boot).
- Both Dean Cain and Teri Hatcher wrote episodes of Lois and Clark: The New Adventures of Superman.
- Jack Klugman, who made no secret of his views on the standard of writing in TV, wrote or co-wrote four episodes of Quincy, M.E. in addition to having showrunner Glen A. Larson thrown off the show and eventually getting writers more to his liking. Including his own brother and sister.
- Don Adams co-wrote two episodes of Get Smart.
- Peter Falk wrote one script for Columbo, in which the Lieutenant is romanced by a Femme Fatale. He held it back until finding the perfect co-star: Faye Dunaway, who turned the role into an Emmy.
- Roger Smith wrote several episodes of 77 Sunset Strip.
- Done quite a bit on The X-Files, especially in later seasons. David Duchovny wrote (and directed) two episodes: "The Unnatural" and "Hollywood AD", while co-developing storylines for seven others. Gillian Anderson wrote (and directed) season seven's "all things." William B. Davis (who plays The Smoking Man) wrote "En Ami."
- Two episodes of Wizards of Waverly Place were written by David Henrie.
- Two episodes of Farscape (Season 3's "Green-Eyed Monster" and Season 4's "John Quixote") were written by Ben Browder.
- Christopher Judge (Teal'c) and Michael Shanks (Daniel Jackson) wrote multiple episodes of Stargate SG-1.
- Joe Flanigan conceived the stories for two Stargate Atlantis episodes, "Outcast" and "Epiphany."
- Nick Offerman earned his first writing credit for a Parks and Recreation script.
- Michael Imperioli wrote several episodes of The Sopranos. This is reflected in Christopher Moltisanti's interest in film and screenwriting.
- Michael Landon got his start in writing with several scripts for his hit series Bonanza, including at least one episode where his character did not appear. He went on to write more episodes of Little House on the Prairie than anyone else, as well as create another successful vehicle for himself in Highway to Heaven.
- Jason Smith wrote a few episodes of Power Rangers Super Megaforce, though oddly not the episode where he reprises his Jungle Fury role as Casey, that season's red ranger.
- Patrick Labyorteaux (Bud) wrote the episode "JAG TV" on JAG.
- Several CSI NY cast members have tried their hand at writing an episode. Gary Sinise has done one or two, and Melina Kanakaredes did an ep where Stella goes to Greece chasing a suspect - an ep which unfortunately drew mixed reviews from fans.
- David Faustino (Bud) co-wrote one episode of Married... with Children.
- Diahann Carroll wrote an episode of her series Julia.
- James Roday has written or co-written over a dozen episodes of Psych, one of which was an elaborate homage to Twin Peaks (his "favorite show of all time, hands down.")
- In one of the Hilarious Outtakes, when James messes up on his lines, his co-star jokes that he should remember the lines since he's the one who wrote them
- St. Elsewhere: Sagan Lewis (Dr. Jackie Wade) is credited for the story of Season 6's "Their Town" as S.J. Lewis.
- Chad Michael Murray wrote an episode of One Tree Hill in which Lucas falls asleep watching Casablanca and dreams the show's cast into a Forties Film Noir world.
- Ellen DeGeneres is credited for the story of Ellen's coming out episode.
- Jerry O'Connell and John Rhys-Davies each received a story credit on Sliders - O'Connell got a few such credits (such as on "Way Out West") while Rhys-Davies only got it for "The Exodus, Part 1." In the latter case, it was the culmination of his feud with the producers and network: they purchased an outline he pitched as an example of how the show could better use its potential, drastically rewrote it into the kind of embarrassing B-movie he'd been complaining about, and since he had just been fired for his outspokenness, reduced his character to a mumbling brain-damaged state, fatally shot him in the heart, and left his corpse behind on a radioactive planet... which immediately exploded.
- Yaphet Kotto wrote three teleplays for Homicide: Life on the Street.
- Paul Gross wrote or co-wrote some of the most memorable episodes of Due South, including the introduction of Kowalski and the two-part series finale.
- Della Reese contributed a script to Touched by an Angel.
- Ray Romano co-wrote several episodes of Everybody Loves Raymond, including some Whole Episode Flashbacks filling in Raymond's past.
- Ted Raimi and Jonathan Brandis each wrote an episode of seaQuest DSV with the help of producer David J. Burke. Brandis was set to direct a second script he had written when the series was Cut Short.
- Denise Nicholas wrote six episodes of In the Heat of the Night.
- As well as directing the first season finale of The Client List, Jennifer Love Hewitt has co-story credit on that episode.
- Stuart Hepburn played a recurrent character in early episodes of Taggart. The producer was so impressed by ideas he had for one scene he was in that he was later invited to come back and write whole episodes; he quickly became one of the most prolific writers after series creator Glenn Chandler.
- Jim Rash wrote "Basic Human Anatomy" for the fourth season of Community.
- Glee's Chris Colfer wrote season five's "Old Dog, New Tricks."
- Outside of three cast members of The Office (US) being staff writers (B.J. Novak, Mindy Kaling, and Paul Lieberstein), Steve Carell also wrote the season 2 finale "Casino Night" as well as "Survivor Man".
- Sara Gilbert received a story credit on Roseanne for the Season Episode "Don't Make Me Over."
- Taken to the extreme on The Red Green Show, as Steve Smith (who played the title character) wrote all 300 episodes. Rick Green (Bill) also wrote for most of the first eight seasons, and other episodes included contributions from Peter Wildman (Buzz Sherwood), Bob Bainborough (Dalton Humphrey), Jeff Lumby (Winston Rothschild), and Patrick McKenna (Harold Green).
- The Wiz had two of the leads of the 2015 NBC production, Elijah Kelley (the Scarecrow) and Ne-Yo (the Tin Man), help write a new song, "We Got It". In it, Dorothy and her friends proclaim that The Power of Friendship can help them defeat Evilene and get their desires granted.
- Maid Marian and Her Merry Men was created and written by its star Tony Robinson, however co-stars David Lloyd and Mark Billingham contributed a lot of ideas and ended up being co-credited for a couple of episodes.
- Schitt's Creek was created by father and son duo Eugene Levy and Daniel Levy, who play father and son on the show. Daniel is also the Showrunner and writes most of the episodes.
- In 1955, The Archers had an episode where Grace Archer, the wife of Phil, was killed off. (It may or may not have been coincidence that the episode went out on BBC radio the very night commercial television began.) The script had Grace's fate be conveyed in the final line of dialogue thus: "She... she died in my arms... on the way to hospital," but Norman Painting, who played Phil, suggested the line go "In my arms... on the way to hospital... she's dead!" Suffice to say that not only was this one of the most talked-about episodes of the soap, but Painting went on to write many, many episodes (and the book Forever Ambridge � 25 Years of The Archers), as well as act in them.
- Louise Jameson, who played Leela in Doctor Who, wrote a Fourth Doctor and Leela audio drama for Big Finish Doctor Who, "The Abandoned."
- In Godspell, "By My Side," the only song retained from the original Off-Off-Broadway production, was composed by its performers, Peggy Gordon and Gilmer McCormick (with lyrics by non-cast-member Jay Hamburger).
- Both of the two musicals written by Lin-Manuel Miranda (In the Heights and Hamilton) featured him performing in the lead role in both their original Off-Broadway runs, and their original Broadway casts.
- Common with Rooster Teeth shows.
- Red vs. Blue had three showrunners\directors with significant roles (Burnie Burns: Church, Lopez, Vic; Miles Luna: Felix; Joe Nicolosi: Jax), Burnie's co-writer Matt Hullum is Sarge/Doc/Wyoming, and the one-offs in season 14 take it one step further. For instance, Shannon McCormick, the voice of Agent Washington, wrote two episodes based on three incompetent agents, of whom he voiced Iowa (his home state).
- RWBY was created by Monty Oum, who voiced Lie Ren and co-written by him with Miles Luna (Jaune Arc) and Kerry Shawcross (Neptune Vasilias). Monty died (his brother took over the role), but the other two remain, even if Kerry's character was put Out of Focus.
- Camp Camp was created by Miles Luna, who voices David, and Jordan Cwierz, who does both the Platypus and Jermy Fartz. Subverted in that the other writers aside from the two don't have roles in the show.
- Nomad of Nowhere has the only writer with credits in all the season 1 episodes, Eddy Rivas, voicing Santi.
- Dan Castellaneta has so far written eight episodes of The Simpsons with his wife Deb Lacusta ("Days Of Wine And D'oh'ses"note , "Gump Roast"note , "The Ziff Who Came To Dinner,"note "Kiss Kiss Bang Bangalore,"note "The Fight Before Christmas,"note "A Midsummer's Nice Dream,"note , "The Ten-Per-Cent Solution"note , and most recently "Havana Wild Weekend"note ).
- He also co-wrote at least one sketch of The Tracey Ullman Show.
- Despite Guest Star Ricky Gervais getting credit for writing the season 17 episode, Homer Simpson, This Is Your Wife, he admits that he didn't really write much of it. He said that he only wrote the plot (which was his wife's idea), a couple of jokes and the song.
- Guest star Seth Rogen co-wrote the episode "Homer The Whopper".
- Harry Shearer, who voices Ned Flanders, Mr. Burns, Smithers, Principal Skinner, etc. wrote a season 28 episode "Trust but Clarify".
- Jack Mercer not only voiced Popeye but wrote several of his screen exploits.
- Will Friedle has written two episodes of ThunderCats (2011): "The Trials of Lion-O - Part 2" and "Birth of the Blades". Both focus on Friedle's character, Lion-O.
- Voice actor Billy West received co-author credit on the The Ren & Stimpy Show episode "Ol' Blue Nose".
- Likewise, Eric Bauza, who voiced Stimpy on Adult Party Cartoon, co-wrote the episode "Altruists".
- April Winchell, the voice of Miss Finster, also did some punch-up writing for Recess: School's Out
- On Mickey's Christmas Carol, Alan Young, the voice of Scrooge, receives a story credit.
- Some episodes of Spliced were written by Mike Kiss, who also voices Mister Smarty Smarts.
- The Tiny Toon Adventures episode "Best of Buster Day"note was co-written by Charlie Adler, who voices Buster.
- The Rocko's Modern Life episode "Rocko's Happy Vermin" was co-written by Carlos Alazraqui, who voices Rocko.
- Mr. Lawrence was a writer for the show on the first three seasons.
- The TV special Garfield on the Town was co-written by Lorenzo Music, who voiced Garfield.
- The Grim Adventures of Billy & Mandy episode "The Bad News Ghouls" was co-written by Richard Steven Horvitz, who voices Billy.
- Like Rocko's Modern Life, Mr. Lawrence (who voices Plankton, Larry and various characters) wrote for SpongeBob SquarePants during the first two seasons. He returned to the show in Season 7. As of season 10, he's now the story editor.
- Katie Crown (who voices Mary and Ms. Baker) wrote a handful of episodes in the second half of Clarence's first season.
- Charlyne Yi, Chloe's VA, was credited for the story of the We Bare Bears episode "Chloe and Ice Bear".
- Wander over Yonder: Sam Riegel, who voiced Emperor Awesome and voice directed the show, wrote 3 episodes ("The Bad Hatter", "The Bad Neighbors", and "The Robomechabotatron").
- The Bobby's World episode "Bobby Phone Home" was written by Tino Insana, the voice of Uncle Ted.
- One episode of Ben 10: Omniverse was written by Ben's voice actor, Yuri Lowenthal.
- Back at the Barnyard: The episode "Little Otis" was written by Chris Hardwick, who voices Otis.
- One episode of Sonic Boom, titled Give Bees A Chance, was written by Cindy Robinson (Amy's voice actress).
- The pilot episode to Puppy Dog Pals, "Hawaii Pug-Oh", was written by Harland Williams, the creator of the show and the voice of Bob.
- Some episodes of Avenger Penguins were co-written by Jimmy Hibbert (the voice of the Avenger Penguin Bluey, Bella, the brown Badly Drawn Brother, Poodle Stink, and Caractacus P. Doom's lackey Harry Slime) and Rob Rackstraw (the voice of the Avenger Penguin Rocky, the Doc from Saskatoon, Cecil Stink, and the Avenger Penguins' mechanic Irv).
- On Looney Tunes: Rabbits Run, Rachel Ramras (the voice of Lola Bunny) co-wrote the script and one of the songs, as well as serving as one of the voice directors.