Despite the common claim that Doctor Who can “do anything” because of its premise—the setting could be anywhere in the universe, at any time in its past or future—the show is also well known to do much the same thing over and over again, for various reasons. These plot, set, and character ideas have appeared so often that they’ve become tropes. And I love me a well-executed trope.
For example, a tried and true way to save money on a show that often suffers from its imagination being larger than its budget is either to set a story in a single location or to set several stories in a filming block in the same location. If the production team can simply re-dress the set and shoot from a different angle to make it look just different enough, the audience (aside from a certain subset of nerds who look for that stuff) won’t even notice.
In the pre-Hiatus/Classic era, this trick was so frequently used as to become almost a joke. Viewers all knew that an alien planet would be set in a quarry (very often the same one), and that interior scenes of the Doctor and his Companion(s) getting chased through a ship’s interior or alien citadel would go past the exact same, re-dressed chunk of corridor a dozen times. (In fact, this trope is so well known it became part of the title of a 2010 commentary book.)
More recently, we’ve seen a number of Welsh locations re-used: the National Museum of Wales and the Temple of Peace in Cardiff, Dyffryn Gardens in the Vale of Glamorgan, Llansannor Court in Cowbridge, etc. The production teams are clever enough that a casual viewer won’t necessarily figure out how often these spots have appeared, but for behind-the-scenes aficionados, some of these favorite locations could slip into trope territory.
Another trick for saving money is to confine a story to a single place. What better way to do that than to have the characters confined to quarters, as it were? When your characters have been left to their own devices, out of the reach of (timely) help and under attack from some sort of oh-god-we’re-locked-in-here-with-it antagonist, you get my favorite Doctor Who trope: the Base Under Siege (BUS).
The BUS has been used for decades, and was particularly common in Troughton’s era (The Moonbase, The Web of Fear, The Tomb of the Cybermen, The Abominable Snowmen…). Examples abound throughout the show’s history (Inferno, The Ark in Space, Earthshock) on into the modern era (42, Mummy on the Orient Express, Under the Lake). It’s kind of fun (for me, anyway) when you realize that you’re in middle of a BUS plot. “Yes! Which character’s gonna get it next?” Or maybe I’m just a little morbid…
Another big favorite in the overused plot category is the Alien Invasion. Practically every story of Pertwee’s era (okay, slight exaggeration—but only slight) falls into this category. While the Doctor was stuck on Earth, he couldn’t go off exploring the universe and running into interesting alien species, so they all had to come to him. That of course meant that Earth became the most invade-able planet ever (well, until one considers the Tivolians), leaving the Doctor and his various friends to save the Earth from destruction time and time again.
Speaking of the Third Doctor’s friends, Brigadier Alastair Gordon Lethbridge-Stewart has become something of a trope himself. As his association with the Doctor grew and changed, the Brigadier could be counted on to be a solid, overly militarily minded chap who had the world’s best interests at heart, but didn’t always see eye to eye with the Doctor. If the Brigadier is in an episode, you know there will be at least one point at which a military solution will be tried, to greater or lesser effect, but usually (if not always) against the Doctor’s advice or wishes.
Some people find tropes boring; for me, they’re more about comfort. Granted, there are plenty of tropes I also hate (see, e.g., “Moffat ex machina“), but those listed above are among the most lasting (see more at The Doctor Who Clichés List), and do more to make me smile than cringe. They give me a sense of rightness, of Doctor-Who-ness about a story that help make me feel all is right with the world for those few minutes I’m watching.
These days I could use more of that feeling.