Initially becoming involved with Doctor Who writing the 1996 Doctor Who – Expanded Universe short story "Continuity Errors" and later the 1999 parody episode Doctor Who: The Curse of Fatal Death, he has gone on to be one of the most critically hailed writers involved in the franchise. In 1999, he was one of the writers asked to contribute for Big Finish Doctor Who, but dropped out because he was only interested in writing for Eighth Doctor Paul McGann—who, at that point, hadn't signed for Big Finish yet. Moffat has since written a short story for one of Big Finish’s Bernice Summerfield anthologies.
His credits for the TV series proper include the Hugo Award-winning episodes "The Empty Child"/"The Doctor Dances", "The Girl in the Fireplace", "Blink" (also won a BAFTA) and "The Pandorica Opens"/"The Big Bang". His two-parter "Silence in the Library"/"Forest of the Dead" was nominated as well, only to lose out to Joss Whedon's surprise hit Dr. Horrible's Sing-Along Blog.
He also eventually replaced Russell T. Davies as the head writer and executive producer of Doctor Who, starting with Matt Smith's first scene at the end of the 2009/2010 story "The End of Time". He's unabashedly One of Us and loves shipping. Upon becoming executive producer, he mentioned that he'd applied for the job once before, but "The BBC already had someone else in mind...also, I was seven at the time". As such, he is fonder than even his predecessor of Continuity Nods to classic Doctor Who, sometimes reaching the level of Continuity Porn.
Frequently throws out red herrings to the spoiler-loving press, calling it "by far the best way of communicating". He also unabashedly and gleefully lies, teases, and generally drives the fanbases of his shows insane. For instance, he kept the fact that his massively-popular show Sherlock was already commissioned for a third series a year earlier until after the final episode of series 2 aired with a shocking ending, even for those familiar with Holmes lore.
He's known to prefer Timey-Wimey explanations to Techno Babble, gleefully uses Stable Time Loop and Temporal Paradox plots, and plays the Long Game when it comes to dramatic tension: he intentionally planted seeds in Doctor Who back in 2006 that didn't begin to get resolved until the 2013 series finale. He's also fond of esoteric plotting and going beyond the traditional boundaries of the franchise and television as a whole.
In fact, he has now written more TV Doctor Who than any other writer, including the late Robert Holmes.
In 2015, he was made an Officer of the British Empire (OBE) for his services to drama just like Russell T. Davies before him.
It has been confirmed that he will step down as showrunner after Series 10 and will be replaced by Chris Chibnall.
- The Adventures of Tintin: The Secret of the Unicorn (feature film, co-written with Edgar Wright and Joe Cornish, 2011)
- Sherlock (a contemporary adaptation of the Sherlock Holmes stories; nine 90-minute episodes note ; 2010-present; co-created with Mark Gatiss)
- Jekyll (all episodes, 2007)
- Doctor Who (51 episodes note ; writer 2005-present; producer 2010-2016)
- 50th anniversary Official Parody The Five(ish) Doctors Reboot (2013)note
- The Comic Relief two-parter "Space" and "Time" (2011)
- The Children in Need special "Time Crash" (2007)
- Also the very Affectionate Parody for Comic Relief Doctor Who: The Curse of Fatal Death (1999)
- The 50th anniversary prequel mini episode "The Night of the Doctor"
- Coupling (all episodes, 2000-2004)
- Chalk (all episodes, 1997-1998)
- Joking Apart (all episodes, 1993-1995)
- Press Gang (all episodes, 1989-1993)
Trope Namer for:
His work on Doctor Who offers examples of:
- Author Appeal: There's a lot of Scottish floating around Who since he took over. Between the Scottish Amy Pond, the Scottish-sounding Twelfth Doctor, and subtle references about Scotland in various forms (Strax's favorite hobby is regular bar fights in Glasgow, Amy chalking up her temper in "Asylum of the Daleks" to being Scottish) he seems to be doing to Scotland what Russell T Davies did to Wales during his tenure.
- Canon Welding: Moffat was a big part of the push to erase the imaginary line between the new series and the old one. According to producers at Big Finish, Steven was in charge of the push to bring revival-era monsters and characters to the main BF series. Up until 2015, Big Finish were not allowed to use characters from the 2005 revival series, but thanks to Moffat (and Russell T. Davies) Big Finish can now have modern monsters meet early Doctors, and the New Series novel line can use classic supporting and spin-off characters, so the Eighth Doctor can meet the Weeping Angels and the Twelfth team up with Benny Summerfield.
- Crack Fic: He likes to indulge in really silly stories in the Doctor Who Magazine Q&A section. Highlights include a comedy bit about the Silence, an encounter between Amy and the Twelfth Doctor ("You've managed to lose that accent") and a very out-there Delgado Master/Gomez Master ship-ficlet. None of which are meant to be taken as Word of God, of course.
- Creator Thumbprint:
- Only "The Empty Child", "The Doctor Dances", and "The Beast Below" don't involve the Timey-Wimey Ball in some way, and of those, only "The Beast Below" doesn't have time travel integral to the plot (as opposed to just landing the TARDIS there).
- He seems to like using Clarke's Third Law as a plot device: apparently supernatural and bizarre (and terrifying) events are eventually explained as the result of malfunctioning advanced technology in a more primitive setting. This is used in "The Empty Child"/"The Doctor Dances", "The Girl in the Fireplace", "Day of the Moon", and "Deep Breath".
- Themes of love and hope are a cornerstone of Moffat's stories, especially with his finales. Bonus points if this involves the Doctor and his companion.
- Distracted by My Own Sexy/Screw Yourself: A bit of a running gag, combined with time travel. It's used sparingly, but pops up in "Space"/"Time" and some other stories. The Screw Yourself trope is, of course, not used explicitly, since Doctor Who is a family show, but he did once write a Master-on-Master Crack Fic as a joke—in which the Delgado and Gomez incarnations ended up bangin'.
- Explain, Explain... Oh, Crap!: Regularly used, but for suspense/horror rather than comedy. A great example in "The Empty Child", where they are listening to a tape recording of the child speaking. After a while the characters notice that there is a ticking sound caused by the tape flicking off the reel after it has finished playing... but the sound's still going, and only then do they realise the child is in the room with them.
- Free-Love Future: Installed in "The Empty Child" and confirmed at every opportunity. Moffat's vision of the future is one in which everyone is free to love/screw whom they like, regardless of gender.
- Mythology Gag: Clara, played by Jenna Coleman and the first new companion to appear after Lis Sladen's 2011 death, may have been named after Elisabeth Clara Heath Sladen. Considering he named the next character and her almost-girlfriend Bill and Heather it starts to look a lot less like coincidence.
- Signature Style:
- Most of his episodes are more psychologically scary, leaving you cowering behind the couch despite a body count of zero. He tends to invoke the Uncanny Valley quite often. His monsters involve masks (Clockwork Men, Empty Child) and statues/mannequins (Weeping Angels, Smilers).
- Also has a tendency to make the most innocuous things absolutely terrifying, like the voice of a child asking for his mother, clock ticks, statues, shadows, birdsong, mirrors, a crack in the wall...and now, after making almost everything else scary, he goes Up to Eleven and makes silence itself terrifying. He wants to leave his audience with no place to hide.
- He's also mentioned Florida several times in a really short time frame. In "The Big Bang", the Doctor and Amy visit "Space Florida". "The Impossible Astronaut" and "Day of the Moon" are partially set in and around Cape Kennedy.
- Scary spacesuits have also shown up in at least two different stories.
- And lots of Buffy Speak. Lots.
- Moffat's stories tend to be about time travel in some way rather than just using time travel as a plot device.
- As mentioned above, he doesn't like Technobabble, and tends to try and subvert it when possible.
- In "A Christmas Carol" when the Doctor's trying to explain why the flying fish like Abigail's singing, he begins to talk about stimulating ice crystals, during which a fish bites him. ("Look, the fish like singing, now shut up!")
- In "The Doctor's Wife" (written by Neil Gaiman but with finishing touches by Moffat), when the Doctor tries to explain why he can't put the TARDIS matrix in another human body, the TARDIS itself begins to spark almost spitefully (Rory's fault, but it was timed way too well), so the Doctor gives up and says "All right, yes, it's spacey-wacey."
- Since his current job involves Time Travel, and all the confusion that naturally occurs, he's developed a tendency to have characters change their names, often giving them a "Young Name" and an "Old Name". This happened with Amelia Pond/Amy Pond, and with Melody Pond/Mels/River Song, and again with Rupert/Danny Pink. In fact, it goes back to "The Girl in the Fireplace", with Reinette/Madame du Pompadour.
- While a lot of these aren't specifically written by Moffat, as producer he's had some say in them (approval, etc.) That being said, there have been a lot of Amy Pond doubles floating around. Let's count: Time-Shifted Amy/Amelia ("The Big Bang"), Time-Slipped Amy ("Space", "Time", "The Girl Who Waited"), Teselecta Amy ("Let's Kill Hitler"), and, of course, Flesh Ganger Amy ("The Almost People"). Let's hope Karen Gillan gets time and a half for all the Acting for Two she did.
- Furthermore, this tendency also shows in his decision to turn the fifty-year-long question of the Doctor's real name into a major plot point in Series 6, that there's a Dark Secret behind why the Doctor purposely conceals his true identity, and that he chose to adopt the name "The Doctor" because he considers it to be a promise.
- Uncanny Valley: Invoked. His monsters are designed to be unsettling rather than outright horrifying.
His other writing provides examples of:
- Creator Thumbprint: Phones seem to be one of his things. They tend to be featured prominently and as integral plot devices.
- Both Sherlock's "A Study In Pink" and Doctor Who's "The Eleventh Hour" feature mobile smart phones as plot devices.
- "The Impossible Astronaut" also has phones as plot devices, both mobile and land-line.
- The Empty Child from the episode of the same name is fond of placing unearthly calls, even to the TARDIS's fake phone.
- "The Beast Below"'s cliffhanger involves a phone call, and "The Pandorica Opens" is kicked into gear by a phone call as well.
- "The Day of the Doctor" has the Doctor answer the fake phone, followed by a nice aerial trip over London outside the TARDIS.
- "The Time of the Doctor": "Urgent: action required. You must patch the telephone device back through the console unit."
- The titular "Bells of St. John" is the phone on the TARDIS.
- Jekyll uses the protagonist's mobile phone as a clever communicator "device" between two sides of the character's personality.
- Coupling has several episodes based around misunderstandings with phones.
- Likewise with Press Gang.
- Deconstructor Fleet: This was hinted at with The Curse of Fatal Death. Both Matt Smith's Doctor Who and Sherlock are defiantly "anti-myth", as it were. Sherlock is a self-aggrandizing genius who gets a taste of his own medicine in "The Reichenbach Fall", when every character he has insulted throughout the series conspire to ruin his reputation and drive him to apparent suicide. The Doctor is a bit friendlier, but makes no bones about being a "mass-murdering psychopath" who often dooms people by offering them an escape from real life. The overall message seems to be that there are no clean "heroes" and that myths are dangerous, though Moffat concedes the childlike wonderment of myths.
- Eagle Land: Harsh flavor in Jekyll and Sherlock; mixed flavor in Doctor Who.
- Everybody Lives: The Ninth Doctor might have coined the phrase but Moffat practically shouts this at the end of every episode. Unlike Davies who is very keen on death, he can't bear to lose even a single character. He even brought back Osgood (Ingrid Oliver) and the fake Osgood.
- Getting Crap Past the Radar: Seemingly one of his favorite pastimes, with spit-take inducing results:Doctor: Shout if you get in trouble.River: Don't worry, I'm quite the screamer. Now there's a spoiler for you...
- Girl-on-Girl Is Hot: Any male character (except the Doctor and Sherlock) will become near-comatose at even the mention of lesbianism. Oddly enough, this includes his version of John Watson, whose sister is a lesbian.
- Noodle Incident: Episodes often begin with these and casual lines are often tossed in. These are often used for humor and to effect a zanier mood.
- Signature Style:
- Most things he's written will have a "Jeff" and/or a "Sally" appear at some point.
- Author Avatars of Moffat appear throughout his works. Joking Apart was based on Moffat's early life as Anti-Sherlock, a sort of fratboy Machiavelli whose schemes never quite take off; Coupling was a rather merciless depiction of his own marriage (with his wife's consent, of course). The Doctor and Sherlock channel his voice quite often, as well.
- Continuing the "Florida" theme, in the Sherlock episode "A Study in Pink", Mrs. Hudson's husband was arrested in Florida.
- He seems to really love the Butt-Monkey and The Chew Toy, and always makes sure one character has almost everything seemingly possible go wrong in their lives. Jeff Murdock, Rory Williams, Molly Hooper...he seems to always like having one character to use as a punching bag.
- Has a fondness for not-so-subtle Audience Surrogates and metatexual references to the popularity of Doctor Who and Sherlock. Also enjoys lampshading the fact that his superheroes are going to win, no matter what; thus, the story becomes more about the journey than the destination.
- Spiritual Antithesis: In a few interviews, he has said that he considers Sherlock to be this to his tenure on Doctor Who, with his take on Sherlock Holmes essentially a dark Foil of the Doctor. Doctor Who is about an long-lived alien time traveler's relationships with his beloved mostly-human friends who keep him "down to Earth", whereas Sherlock is about a human detective who shuns emotions and friendly relationships. Where the Doctor is an alien being who's afraid of losing touch with his "human" side, Sherlock Holmes is an ordinary human who wants to prove to the world that he's something better than human, or, as Steven himself put it, "The Doctor is an angel who wants to be human; Sherlock is a human who wants to be a god."
Tonally, they're also complete inversions of one another: Doctor Who is a whimsical, light-hearted science-fiction series that's known for its dark undertones, and Sherlock is a gritty crime saga that's known for its whimsical undertones.