For over 50 years, Doctor Who has changed the face of science fiction. With more than 800 episodes, and adventures spanning all of time and space, this icon of television science fiction may seem a little intimidating. But the good news is, it’s really quite simple. Here’s the io9 guide to Doctor Who.




Welcome back to the io9 Guide series, where we write simple but comprehensive guides to the most important universes of science fiction and fantasy. These guides are aimed at casual viewers in search of a quick refresher, as well as seasoned fans who want to debate the meaning and essential knowledge of a subject .

What is Doctor Who about?

Simply put, Doctor Who is a show about an alien time-traveler who goes around helping people, usually with the help of one or more human traveling companions.

Doctor Who stands out among other science fiction series, because it tries not to focus on the dark, gritty aspects of the medium. It’s a show about relentless optimism, both in the hope of finding a peaceful conclusion to any conflict, and in the hope of discovery and appreciating the beauty of the world around us. It’s about finding the joy in the extraordinary and the ordinary, from a majestic nebula to the smallest human act. The Doctor travels with people not just to save worlds across time and space, but to explore and see the universe, through their own eyes and through the lens of the friends they travel with.

Even in the show’s darkest moments, the Doctor’s fury often comes not from a place of anger, but a laser-focused sense of justice, an utmost belief that evil across the universe must be fought. And unlike many action heroes, the Doctor does not carry a weapon into battle—they use their intelligence and wit to outsmart opponents, and occasionally a trusty gadget called the sonic screwdriver (which isn’t a weapon, but a high-tech tool that opens locked doors and acts as a scanning device). Even when Doctor Who is all about its hero fighting monsters and villains, it’s battles waged with words and wit rather than weaponry and explosions, a rare sight in science fiction on TV.




But perhaps above all in Doctor Who’s uniqueness is its thoroughly English sensibility. All media is inherently shaped by its country of origin, but few wear it so brazenly on their sleeves as Doctor Who. It’s steeped in British culture, a celebration of English eccentricity and the sort of stereotypically chipper reputation the little island nation has—and it’s been in turn embraced by that culture, and cherished as something truly representative of its ideals. Doctor Who’s iconic imagery—the Daleks, the TARDIS—have become more than just representations of the show, but of British popular culture as a whole .

The History of Doctor Who

The original TARDIS team: The First Doctor, Barbara, Susan, and Ian. Image : BBC

Doctor Who was developed as an educational program aimed at young children—the idea of a grandfatherly alien taking friends through time and space to examine both factual historical events and scientific ideas through drama.



At the time of its creation, the show was beset by daunting odds. The BBC did not place much faith in the show, and as a children’s production its budget was restricted compared to the company’s traditional drama output. On top of that, Doctor Who was also created by outsiders. The idea came from Sydney Newman, a Canadian who was looked down upon by his fellow BBC executives, and was initially produced by Verity Lambert, who was the only female producer at the BBC. Its first director, Waris Hussein, was one of a handful of Indian directors at the BBC in those years.

The show’s first episode broadcast on November 23rd, 1963, and garnered a lukewarm reception (it was also overshadowed by rolling news coverage for the assassination of John F. Kennedy, which had occurred the day before). The series found itself on the verge of cancellation almost immediately, but Doctor Who’s fate would be changed just a month later with the beginning of the second storyline, The Daleks.


At first, Newman was incensed, having previously demanded that the show never stoop to featuring “bug-eyed monsters”—but the story, which introduced the cyborg Daleks, was massively popular among audiences. The Daleks turned Doctor Who into a sensation overnight (and prompting a pop culture hysteria in the late ‘60s, dubbed “Dalekmania,” that spun off into toys, pop songs, and even movies).

The Doctor encounters his most infamous foes for the very first time. Image : BBC

The show remained successful but found itself on the brink of cancellation once again three years later. Leading actor William Hartnell had become increasingly ill, and his deteriorating condition making it tough for the actor to learn his lines. Combined with the fact that much of the original cast and crew on the series had departed the show, he took the decision to leave the series.



Instead of canceling Doctor Who, the producers took an incredibly risky decision, recasting the role of the Doctor, coming up with a reason that the character’s alien biology allowed him to completely change his body and appearance when near death. In the 1966 episode The Tenth Planet, actor Patrick Troughton took on the role of the Doctor, ensuring that the series could go on to become one of the longest running science-fiction shows in history.

For the next 20 years, Doctor Who became a mainstay on the BBC, but eventually declining budgets and declining interest from upper management at the corporation saw the show come to an end in 1989, following seven Doctors and 26 seasons of stories. Outside of a 1996 made-for-TV movie produced with Fox in an attempt to establish an American-produced series, it would take another 16 years for Doctor Who to return to television.


The Ninth Doctor and Rose run across Westminster Bridge in the very first episode of Doctor Who’s modern era. Image : BBC

When the BBC decided to bring the show back, it was produced by Russell T. Davies, then known for his work on The Second Coming and the groundbreaking gay drama Queer as Folk. The new version of Doctor Who (colloquially dubbed as “New Who,” or “NuWho” among fans) was not a reboot but a continuation of the “classic” era of the show, following the ninth incarnation of the Doctor and his adventures with a young London shop assistant named Rose, played by Christopher Eccleston and Billie Piper, respectively. The series was an instant hit, and its blend of sci-fi adventure and human storytelling (focusing on the home life of Rose and her family) made it accessible to fans of the old series and newcomers alike.



The show’s 50th anniversary special, “The Day of The Doctor,” held a world record for being simultaneously broadcast in the most countries at once when it aired on November 23rd, 2013.

Last year, Doctor Who underwent another radical transformation: for the first time in its history (officially at least), a woman—Broadchurch star Jodie Whittaker—was cast as a the latest incarnation of the Doctor, the 13th. Although the possibility of female Doctor has existed at points throughout Doctor Who’s history, it’s only been in recent years that the show has openly acknowledged (and “canonized”) that Time Lords can regenerate into any gender during the renewal process, depicting gender as randomized as any other particular whim during regeneration. Beginning with Whittaker’s first season in the TARDIS in October 2018, it opens up Doctor Who’s future to a bigger potential of future Time Lords than ever before .

The Three Constants

The Constants: The Doctor (the 13th in this case), the Companion (one of 13's, Ryan Sinclair), and the TARDIS. Photo : BBC


Although by its very nature Doctor Who is a show about change and renewal, and its format has allowed it to dabble in many different genres over the years, there are three crucial components that have remained throughout: the Doctor, their traveling allies, and their time machine, the TARDIS.



The Doctor is from an alien race known as the Time Lords, an extremely advanced society who gained mastery over the ability to travel through time. Such power drove the Time Lords to adopt a strict policy of non-intervention, remaining isolated from other galactic races and to never interfere with the timeline. The young Doctor vehemently disagreed with this, and with his granddaughter Susan, he fled his home planet to travel the universe, helping people in need. Aside from a vast knowledge of science, the past (and future), and technology, the Doctor also has two hearts, and, like all Time Lords, the ability to come back from the dead in a brand new body, changing personality as well as appearance each time.

A brief smattering of friends and Companions past. Photo : BBC

The Doctor rarely travels alone, instead recruiting friends and allies—sometimes called assistants, but usually known as Companions—to go on adventures with. These companions act as an audience surrogate, someone to ask questions so the Doctor can explain what’s going on. But they also offer an important human connection to the Doctor, a friend as well as a reminder of all the people they strive to protect on the many galaxy-spanning travels.

Over 40 companions have accompanied the Doctor on adventures, from a variety of backgrounds and occupations. These include warriors and soldiers, like “savage” tribeswoman Leela, space pilot Steven Taylor, and Time Agent Jack Harkness. And, doctors and scientists, such as Zoe Heriot, Martha Jones, and Liz Shaw. Also, journalists, like the beloved companion Sarah Jane Smith. And finally, “normal” people—like shop assistant Rose Tyler or troubled teen Ace.


But the Doctor and the companions need to be able to travel through time and space for their adventures: and that’s where the TARDIS, or Time And Relative Dimension In Space, comes in. The TARDIS has a special piece of cloaking technology called a chameleon circuit that, upon landing in a new location, allows it to mask its exterior to help the ship blend in. When it landed in 1960s London, it turned into a blue Police Public Call Box (at the time, they were a common sight in England, special phone boxes that the public could use to contact the police), but the circuit broke, leaving the TARDIS stuck as a police box ever since.

Aside from its ability to travel back and forth in time and being nearly-impervious to attack, The TARDIS holds another secret: the fact that it is “Dimensionally Transcendental,” or “bigger on the inside than the outside.” The TARDIS holds a huge amount of rooms inside its phone-booth exterior, from the console room where the Doctor pilots the ship, to bedrooms, libraries, gardens, and even swimming pools. This aspect of the ship is so iconic in England that people have come to accept describing something as “like the TARDIS” as a colloquialism for it appearing larger on the inside than you would have expected .

All The Strange, Strange Creatures

Just some of the Doctor’s many enemies from over the years, as seen in the 2011 series. Image : BBC

But there’s something just as important to the fabric of Doctor Who as these three elements: all the monsters and villains the Doctor defends the universe from.



Although there are an incredibly vast amount of one-off aliens and monsters across the shows’ run, there are also several recurring foes, such as the iconic Daleks (cyborg creatures genetically altered to feel nothing but hate, and a yearning to exterminate all other life), Cybermen (cybernetically enhanced cyborgs who “upgraded” their bodies seeking perfection), Silurians and Sea Devils (aquatic reptilian creatures who occupied the Earth before humankind developed) from the classic series, and newer additions like the Weeping Angels (stone statues that can only move when you’re not looking at them).


Many of Doctor Who’s monsters play on then-current fears—the Daleks were inspired by the Nazis for example, and the Cybermen about a fear about the expansion of “spare parts surgery” and mechanical prosthetics. But another aspect of the classic Who nasty is the idea of turning an ordinary element of society into something scary and dangerous (a prime example of this are the Autons, plastic shop window mannequins that come to life and attack people), making them easily imitable by children on school playgrounds after watching an episode.

Doctor Who has had a long reputation for its scary monsters; the show was even the target of infamous social activist Mary Whitehouse in the 1970s for being too frightening for children to watch. And its monsters have become such a cultural touchstone to the point that fans of the series coined the phrase “watching from behind the sofa”—children eager to watch but ready to hide when the monsters appeared on screen—another turn of phrase that has entered the UK’s pop cultural lexicon .

Where To Start Watching

Given the fact that there is so much Doctor Who out there, getting into the series can be incredibly daunting for a newcomer—but there are several jumping on points. For the sake of simplicity, let’s divide each one between the post-2005 Doctor Who and the Classic series.

The four modern Doctors, before Jodie Whittaker: Christopher Eccleston, David Tennant, Matt Smith, and Peter Capaldi. Photo : BBC

New Doctor Who

The revived version of Doctor Who is the easiest jumping on point—not just because it was designed to be approachable to newcomers, but because (despite being over 10 years old at this point), it’s a lot more palatable to experience if you’re not used to watching older television. If you want to dip your toes in the show, start off here.


Season 1, 2005: The first season is naturally a good starting point, as it was intended to be. Introducing the new tone of the series, the new Doctor and his companion Rose, as well as familiarizing new audiences with concepts like the Time Lords, Daleks, and other Doctor Who hallmarks. The only downside is that the season is starting to show its age—it was shot in standard definition with CGI effects that haven’t quite held up.

Season 5, 2010: Season 5 didn’t just introduce the Eleventh Doctor (Matt Smith) and a new companion, Amy Pond (Karen Gillan). Many behind the scenes changes occurred as well, with producer Russell T. Davies replaced by Steven Moffat as showrunner. This also signified a tonal shift for the show, with less of a focus on the home lives of companions, and a further drift into science-fantasy elements. The show’s visual aesthetic changed too, now shot in HD with a darker, more cinematic approach. This is also the season where Doctor Who really began increasing in popularity in the U.S., so if you’re an American fan-to-be, you can see where all the fuss about it started.

Season 10, 2017: The first two seasons of Peter Capaldi’s time on Doctor Who deal with leftover elements from the Eleventh Doctor, mainly in the form of the Eleventh Doctor’s second companion, Clara Oswald (Jenna Coleman), who plays large roles in the major arcs of each season. For a clearer entry point into the Twelfth Doctor’s run, ironically we suggest you try his final season. Aside from the return of Missy (Michelle Gomez), the latest incarnation of The Doctor’s foil, the Master, first introduced in 2010, it is largely standalone and doesn’t particularly have any important holdovers from prior seasons. That’s mainly because the Doctor gets a new companion: Bill (Pearl Mackie), a young student he takes under his wing after operating on Earth in secret as a university teacher.

Season 11, 2018: Might as well join in with everyone else! Jodie Whittaker’s first season as the Doctor is another entirely new break for the show. It will have a new Doctor, three new companions, a new showrunner—Chris Chibnall, replacing Moffat—and an overhaul in its style and tone. It’s the perfect jumping on point if you want to be alongside everyone else experiencing the first female Doctor.

Classic Doctor Who

The eight Doctors of Who’s “Classic” era. Photo : BBC


If you find yourself enjoying the show and want to experience more, then it’s time to go back and try out the older series, where it’s more than likely your interest in the series will counteract the aged effects work and old school cardboard sets. If you can, you’ll find a huge plethora of interesting stories.



The Fourth and Fifth Doctors: Some of the most popular of the Classic Doctors, the Fourth (Tom Baker) and Fifth (Peter Davison) Doctor’s adventures aired between 1974 and 1984. The fourth Doctor’s era, in particular, is Classic Doctor Who at the height of its popularity, with many stories that fans consider to be iconic debuting during this period. There’s also a great blend of different genres, from periods influenced by gothic horror, to more light-hearted adventures, and to a shift to more a “hard science” in the 1980s. The revived version of Doctor Who is heavily influenced by this period too, so it’s a natural stepping stone from there.

Third Doctor: Jon Pertwee’s tenure as the Third Doctor is relatively isolated from the rest of the Classic series. For most of the period the Doctor is exiled on Earth, unable to use the TARDIS, and finds himself working with a UN-backed military task force called UNIT to fight alien incursions on Earth. If you like the sound of Earth-based science fiction, and a bit more of an action-oriented tone (Pertwee’s Doctor had a James Bond-ian love of gadgets, vehicles, and even kung-fu!), look no further.

The TV Movie: Just as isolated is the 1996 TV movie. The sole TV adventure of Paul McGann’s Eighth Doctor is not Doctor Who at is best, but the film does a relatively decent job of introducing the show’s concepts to a new audience. If you want to see an Americanized take on Doctor Who, it’s worth a watch.

Sixth and Seventh Doctors: These two Doctors, played by Colin Baker and Sylvester McCoy, presided over the Classic era’s decline. Affected by budget cuts and some middling stories, many regard them as “weaker” Doctors. There are still some great stories in there, however, but I’d advise watching other eras of Doctor Who before trying out these two Doctors—although the final year or so of McCoy sees a resurgence of quality and some challenging storytelling.


First and Second Doctors: For the most diehard fans. If you’ve gobbled up all of New Who and trawled your way through much of the classic show, only then try to watch this early period. Many episodes from the era are missing, so you can’t watch everything, but the combination of being over 50 years old, in black and white, and very much products of their time mean that only the most loving fan should go back. If you do though, you’ll be rewarded with some fantastic stories, and a chance to see where iconic elements of the show began.

Want some more specific, tailored stories to check out? Here’s a list of must-watch classic episodes.

... And How To Catch Up

The 13th Doctor, newly regenerated, dashes off in her debut episode, “The Woman Who Fell to Earth”. Photo : BBC

BBC America is the home of Doctor Who in the U.S., and the channel frequently runs repeats of post-2005 episodes (especially in the run-up to the show’s return—which now broadcasts on the same day as it does in the UK—when there are lots of marathons of former series). However, you need to pay for cable access, and it can be a pricey endeavor for a single show.



If you prefer streaming, then you better have Amazon Prime Video: it carries all 10 seasons (with the 11th on the way) exclusively. You can also purchase the entire series on iTunes, and the seasons are also readily available on Blu-ray and DVD.


The Classic show is a little harder to find: if you’re a completist, the only way to get as much as you can is to purchase stories on DVD, with almost every available one released at this point, but more recently the BBC has started releasing Blu-ray versions of Classic seasons, starting with the debut seasons of the Fourth and Fifth Doctors. For streaming, your options are quite thin—the odd classic Who story is still available on Amazon Prime Video in the U.S., such as the recent partially-animated releases of lost stories like “Shada” and “Power of the Daleks,” but if you want a wider variety then you have to sign up for BritBox, a U.S. and Canada-only subscription service run by the BBC and fellow UK Broadcaster ITV, that has a host of stories from every season of the classic version of the show .

Do I Have to Have Watched Everything Else If I Want to Start Right Now?

Doctor Who’s long history and overarching threads, familiar faces, and familiar foes are some of its greatest strengths, and the reasons it has endured for over half a century of adventures—but it’s also a weakness in that it’s completely daunting for newcomers to get into.

While the modern version of Doctor Who has introduced more connecting storylines and arcs that develop over the course of multiple seasons in comparison to the largely serialized style of the classic series, you don’t have to start from the beginning of season one in 2005 (or all the way back in 1963!) to get prepared for the latest season of the show. As long as you’re aware of the concepts and constants we’ve outlined in this guide above, you can practically jump in at any point in the show’s history, from the very beginning right up to the latest season.

So there you have it: All of Time and Space. Where do you want to start?

Update: 10/5/2018


The io9 Doctor Who Guide was updated to reflect the last few years of the franchise.