An Unearthly Child:
pilot -	As Barbara and Ian enter the classroom to offer Susan a lift home, Barbara's shoe gets stuck in the door, and she struggles for quite a while to free it.
pilot -	While Ian and Barbara are driving in the car, a stagehand can be seen moving behind them.
pilot -	Carole Ann Ford flubs a line when talking about "John Smith and the Common Men". She says that they have gone from "2 to 19" when she corrects herself and says "19 to 2 on the hit parade".
pilot -	After Ian and Barbara enter the TARDIS, you can see a shadow moving along the TARDIS doors.
pilot -	The TARDIS doors won't shut.
pilot -	During a tracking shot of the TARDIS, the cameraman stumbles and a clatter is heard.
pilot -	You can hear the PA calling the shots on some sections if you listen carefully (one example is when the Doctor is operating the TARDIS console, shortly before Ian is "zapped").
ep 1 -	When Ian and Barbara enter the TARDIS for the first time, Susan operates the door switch. Later on, when the Doctor electrocutes Ian, he uses the exact same switch!
ep 1? -	While Ian and the Doctor are examining the clock in the TARDIS, both of them manage to interrupt each other.
ep 1? -	Ian claims that the Doctor closed the TARDIS doors, though in fact it was Susan.
ep 3 -	There's some delightful running on the spot with scrolling background as the TARDIS crew are escaping through the forest.
ep ? -	At one point, a stagehand can be seen through a gap in one of the corners of the TARDIS (it's quite a big gap too, maybe 10-20 centimetres).

The Daleks:
ep 3 -	There are some painfully obvious shots of Susan "running" through the forest by jogging-on-the-spot against a scrolling background.
ep 3 -	In one shot of the interior of the Dalek city, a boom shadow is clearly visible.
ep 6 -	When the Thals are jumping across the chasm, Ian grabs onto the rock wall when he lands. His handhold breaks off with the rip of tearing styrofoam, and the white spot where it was is visible for the rest of the scene.
ep 6 -	In one of the scenes in the Dalek control room, one Dalek runs into the control console with an audible THUD.
ep 7 -	One of the Daleks rattles noisily as it trundles down a corridor. Obviously one of its castors wasn't balanced correctly.
ep 1? -	While Ian and the Doctor are examining the clock in the TARDIS, both of them manage to interrupt each other.
ep ? -	It is mentioned that the Thals have been travelling for four years, but later on the figure has been shortened to just over one year.

The Edge of Destruction:
ep 1 -	You can see the studio floor in the "white void" outside the TARDIS door in early shots.

Marco Polo:
ep 2,3 -	The caption at the end of episode 2 says "Next Episode: The Cave of Five Hundred Eyes", but the next episode is simply called "Five Hundred Eyes".
ep ? -	"Peking" is mentioned several times, but this is an anachronism - this story is set in the late 13th century, when Peking was known as "Khan-balik".

The Keys of Marinus:
ep 1 -	Play spot-the-stagehand when one of the Voord falls through the hidden panel and the trick wall spins around.
ep 6 -	One of the Voord comes into the control chamber, trips on the bottom edge of the door, and stumbles over to Yartek.
ep ? -	Just after Barbara is taken inside the city, on the next shot you can see a stagehand dart behind Ian.
ep ? -	When Susan falls into the pyramid, a stagehand can be seen venturing onscreen before the camera cuts away.
ep ? -	Ian goes to a lot of trouble miming to show the extent of the force-field around the TARDIS, but then Susan ruins it all by casually walking in front of him and hence straight through the "barrier".
ep ? -	Barbara is only seconds ahead of the Doctor and co. when arriving at Morphoton, but somehow she gets the chance to meet Altos and have a nice chat about fashion before the others arrive.
ep ? -	Considering the travel dial is his only link back to the TARDIS, Ian seems a bit too eager to swap it for a piece of fur from Vasor.

The Aztecs:
ep 1 -	During the sacrificial scene, there is a visible jump as the camera bumps into the altar.
ep 4 -	At one point, the audio engineer accidentally plays the story's incidental music at the wrong time, and quickly turns it off a split second later when he realises his mistake. This happens just after Cameca says, "The handmaiden must come to the temple with me" and Ian sends Susan off.

The Sensorites:
ep 1 -	The camera crashes into a desk in front of the Doctor while he's pondering whether the Sensorites will kill the TARDIS crew.
ep 2 -	Watch out for the moment when the Sensorites step on each other's toes.
ep ? -	At one point, Captain Maitland has to cut out the lock of one of the spaceship doors using a drill, leaving several large white marks on the door. The problem is that you can see these marks on those doors, even before the scene in which they were made.
ep ? -	In one scene, the action cuts from the underground caves back to the city, but the sound effect of dripping water carries on until about halfway through the scene, when the grams operator finally wakes up and turns it off.

The Reign of Terror:
ep 3 -	During the gunfight to rescue Susan and Barbara from the wagon taking them to be guillotined, one soldier is seen kneeling by a wheel (on the right of the screen) - then in the next frame, he's suddenly standing up.
ep ? -	Jules Renan claims that the collaborators on the escape line are on a first-name basis only, but later he casually refers to two of them as Rouvray and D'Argenson.

Planet of Giants:
ep 2,3 -	The climax to episode 2 involves the sink being emptied, during which the plug is pulled out of the drain and placed on the bench. But by the start of episode 3, the plug has found its way back into the sink again, conveniently allowing our heroes to climb up the chain and escape.

The Dalek Invasion of Earth:
ep 3? -	In one scene, when London is supposed to be abandoned, you can clearly see a truck driving calmly by in the background.
ep 6 -	When the rebels ambush the Dalek passing through the door, the Dalek's eyestalk is looking straight at them as it enters, but it quickly turns away to allow the rebels catch it by "surprise".
ep 6 -	As the Doctor unlocks the TARDIS door, listen for the faint sound of a Dalek screeching in the background. (Apparently this is an audio problem which arose during duplication of the original master tape).
ep 6 -	The Dalek's reason for invading Earth is because of Earth's magnetic core, which they claim "no other planet has". Unfortunately the metal meanies seem to know as much about geophysics as they do about diplomacy - planets with magnetic cores are now considered commonplace, with all the planets in our solar system possessing one, for starters.
ep ? -	During the attack on the Dalek saucer, a Dalek is pushed down the ramp, falls over and lies still. In the next shot the head of the Dalek is pointing in another direction.
ep ? -	Listen out for the Black Dalek clearing its throat before making a speech.
ep ? -	Nice to see that pleasure boats still sail along the river Thames, even after ten years of Dalek occupation!

The Rescue:
ep 2 -	When Sandy (Vicki's "pet") is seen in its cave just before Barbara kills it, a stagehand is visible moving around behind it to the left.

The Romans:
ep 2 -	Nero's lyre-playing is embarrassingly fake - the notes "plucked" by the actor differ greatly from the music being played.
ep 2 -	Hartnell's dodgy memory strikes again the first time the Doctor meets Tavius; there's an embarrassing pause as Hartnell forgets what to say, and then he remembers just as Michael Peake is going on to the next line of the script.
ep 3 -	A boom mike makes an appearance while Tigilinus is chasing Nero around, trying to put his olive garland on.
ep 4 -	The gladiatorial fight scene which begins this episode contains one of the few instances of mooning in the show's history. After Ian's friend has killed one of Nero's guards, Nero kicks the body off the stage and down into the arena. The guard's very short skirt then flies up and gives the world a good long glimpse of shapely buttock.

The Web Planet:
ep 1-6 -	The backdrops in this story cause a great deal of credibility problems -- barely an episode goes by without a character walking past a "mountain range" and casting a shadow on it! (One example is in episode 2, when the Doctor and Ian walk past the mountains just after the Menoptera destroy Barbara's gold bracelet.)
ep 1 -	Hartnell loses his lines and ruins an entire scene. After Ian's line, "How do we open the doors? We have no power?", the pain begins. The Doctor is supposed to explain the presence and purpose of an item he is holding, but he can't get his lines out. In fact, he appears to have forgotten the entire purpose of the scene. Ian has to look three times at the small object -- during the eternity of horrible and irrelevant improvisation -- before Hartnell spits out inexplicably: "This is not merely a decorative object". He then goes on to finish the scene as if it had all made perfect sense: a real trooper.
ep 1 -	Outside the TARDIS, in the same scene where Ian's pen vanishes, a boom mike shadow makes a brief but unmistakeable appearance on the front of Ian's coat. Look for it as he follows the Doctor off the set, a split second before he whirls around to see if he is being followed.
ep 1 -	In the scene where Barbara goes in to see if Vicki has awakened from her aspirin-induced nap, she sits down in front of a very reflective wall (you can see her reflection at the end of the scene, when she gets up abruptly and leaves the room). The blooper comes soon after she first sits down, however: you can see a spotlight being moved in to shine on her, but it also reflects into the camera. In the next shot of Barbara it has been moved.
ep 1 -	At the episode's climax, Hartnell returns to find the TARDIS missing, and has the line, "My TARDIS". It was dubbed over for some reason, and incredibly badly. His lips move almost a full second before any sound is heard.
ep 2 -	In the scene immediately after the Menoptera destroy Barbara's gold bracelet, the Doctor and Ian walk onto the set. Some mountain ranges ring the background, but when Hartnell walks on, he casts his shadow on them -- making it all too obvious that they are four inches high and right next to him!
ep 2 -	In the scene right after Vicki leaves the TARDIS and encounters the Zarbi, the Doctor and Ian are still being taken somewhere by their own group of ant creatures. They enter the set from directly in front of the camera, walking away from it with their backs to the lens. Look for another great shadow on Ian's coat just as they move away: the camera and the cameraman's head!
ep 3 -	When Ian is running away from the Zarbi, there is a scene where two bloopers happen in rapid succession. First, a Menoptera flies down to land behind him and follow him; the rope on which he was lowered shows brightly against the black background. A half-second later, the "Larvae gun" (that short little Zarbi-owned monster that looks like it was constructed out of spare parts for a car-wash) is dragged onto the scene; the rope used to pull it can be seen on the floor.
ep 3 -	A Zarbi is scuttling about when it manages to run straight into the camera with a loud CLUNK. The camera shakes for a second or two after that (and wouldn't you if you'd just been clunked by a Zarbi?)
ep 4 -	At the episode's climax, the Menoptera spearhead flies in to do battle with the Zarbi. And there's not a single one of them without a hugely visible rope dangling them from the ceiling.
ep 6 -	Just as the episode begins, the Animus dome descends to speak with the Doctor. "You attempted escape?", it asks. Says Hartnell: "We have been on a slight ... exploitation." Lines, lines, lines. It appears very possible that he misread his cue card because of the hazy plastic shield through which he was looking at the time.
ep 6 -	At the end of that first scene, the Doctor and Vicki are led off, ostensibly to "the centre"; Hartnell is groaning and clutching his face. The camera cuts to Barbara, who is supposed to be on the other side of the planet -- yet we still hear Hartnell groaning pretty loudly! Obviously he didn't realise that his scene was over, and that the camera was long off him. Poor Jacqueline Hill just has to ignore him, and keep a straight face while saying, "The Doctor will have reached the control section by now".
ep 6 -	The string from which the Animus itself is suspended is clearly visible in almost every scene.
ep 6? -	Watch the mountains closely, and in some scenes you can see the wooden supports holding them up.
ep 6 -	Just after the Animus is destroyed, a group of Zarbi proceeds to dig out water from the planet surface, and some Menoptera come over to join them. The weight of all the actors makes the wooden stage creak fearfully for a good long while. This is far from the dusty planet surface the designers were trying to create.
ep 6 -	When the TARDIS finally takes off (thank God!), we see a side view of it. One of the window panels is broken and is leaning inward ridiculously.

The Crusade:
ep 3 -	After El Akir says "And death is very far away" to Barbara, you can hear someone call "Cut!" just before the credits roll, on an otherwise perfect episode.

The Space Museum:
ep 1 -	As the Doctor bends over to examine some footprints on the ground, you can see his shadow being cast onto the "landscape" behind, plainly showing that it's just a painted backdrop after all. (Well, what did you expect?)
ep 4 -	How does the Doctor get the Time-Space Visualiser into the TARDIS? It's too big to fit through the doors!
ep ? -	William Hartnell takes three tries to say the word "fluorescent".

The Chase:
ep 1 -	As the Doctor, Ian, Barbara, and Vicki are watching the Time-Space Visualiser, Ian is seen singing along to the Beatles' "Ticket to Ride". What's amazing is that he knows the words, despite coming from Earth in 1963 (two years before the song was released).
ep 1 -	Note that when Barbara goes back to the TARDIS to turn off the Visualiser, she walks on to the set where the Visualiser is from the wrong direction! She should have entered from the door on the left (where they all walked off when the Doctor announced "We're about to materialise!"), but instead she just walks on from nowhere. Not only that, but she yells from where she walked on to the Doctor to come quickly, which is followed by him entering from the same nowhere that she did!
ep 1 -	When Ian yells "Hello!", his echo doesn't match.
ep 1 -	When Vicki leaves in a huff, she leaves a screwdriver on the Time-Space Visualiser. It promptly falls off with a loud clatter that William Hartnell reacts to by groaning.
ep 2 -	Look closely at the back of the Aridian's heads, as you can almost always see the actor's hair sticking out from under the mask.
ep 2 -	When the Doc and co. are on Aridius, in the background you can see the sand dunes stretching off into the far distance, but when they walked across the screen they cast shadows on the dunes - rather giving away the fact that they were just cardboard cut-outs.
ep 2 -	When the Doctor, and Barbara are being held by the Aridians, Vicki comes to find them. When she is rushing to meet them, she knocks an Aridian over. Keep your eye on him. After a few seconds, he gets up, looks confused for a second and then looks at someone behind the camera. He then "sneaks" off the set.
ep 2 -	Why is it that the Daleks could get close enough to obtain a very clear picture of the Marie Celeste, but still were x minutes away? And besides, how can you have a "10 minute lead" in the Space/Time continuum?
ep 2,4 -	The Doctor appears to leave his coat on Aridius, though he somehow has it back by the time they reach Mechanus.
ep 2? -	The tour guide with the extremely fake Noo Yawk accent obviously failed Physics 101. If it really took 30 seconds to reach the ground if you jumped off the Empire State building, it would be over 4,000 metres tall! In fact, Manhattan's best-known landmark is 443 metres tall, and leaping from the top will turn you into sidewalk pizza in less than 10 seconds.
ep 3 -	Watch out for the motionless and rather knackered-looking Daleks standing on either side of the ramp into the Dalek ship. These are actually 2 ex-movie Daleks which were returned to the BBC to be used in the show, but there wasn't enough time to replace the movie style large base and jam-jar dome lights... So these bits were simply removed in the hope no-one would notice. [This info comes from the instruction sheet for the Sevans Models Dalek kit.]
ep 3 -	Just after the Doc & Co. escape from Aridius (when Barbara says that he wasn't bursting with enthusiasm), a boom shadow moves across the Time Rotor (or whatever you call that gadget thingy).
ep 3 -	Just after the previous blooper, Ian, Barbara and Vicki all gather around the Doctor. Vicki puts her hands deep in her pockets and starts to wiggle her legs, move her hands (in the pockets) and shake her hips. Judging by the desperate (but hilarious) facial expressions (a silly embarrassed grin with a wide urgent look in her eyes), she had a need to visit the Ladies room...
ep 3 -	This may or may not be a blooper: in one of the scenes in the TARDIS, Vicki starts pointing out that "Doctor! The rotor is slowing down!". To which he responds, "No, but I'm not ready!". The blooper is (I think) that Vicki seems to be pointing at those two strobe light circular thingies on the console, when the rotor (at least I thought it was) is in the central column. If the rotor is those two strobe thingies, then the blooper is the fact that from that point in the story on, whenever you see the TARDIS console (when the TARDIS is in flight), you never see those strobe things active. Someone either forgot to turn on the strobe things, or Maureen O'Brien doesn't know where to point...
ep 4 -	Before the TARDIS materialises in the Haunted House, you hear the Dalek Time Machine materialisation sound for no reason whatsoever. Then you hear and see the TARDIS materialise.
ep 4 -	As the TARDIS materialises in the haunted house, note the shadow of the person on the TARDIS door who quickly runs away when it has fully materialised.
ep 4 -	The Doctor and Ian enter Frankenstein's lab in the haunted house. They see the Monster lying unanimated on a table. Behind the table is a large ventilation screen. Behind this screen is an empty Dalek - note that at this point in the story, the Daleks weren't supposed to have arrived yet. A later scene in this same room shows that Dalek in action, "exterminating" the Monster.
ep 4 -	Listen for when William Hartnell says: "I say, I think we'd better go and check where Vicki and Barbara is!". It's shortly after he and Ian enter the haunted house.
ep 4 -	When the Doctor and Ian escape from Frankenstein's monster and the monster lies down on its couch again, we hear Vicki's next line "What's that in aid of?" a few seconds before she actually says it in the next scene. (Apparently, Maureen O'Brien jumped her cue and said the line before the camera was actually on her.)
ep 4 -	Immediately after the previous blooper, Barbara's next line, the quote about "Ask not for whom the bell tolls..." seems to suggest that we should have just heard a spooky-sounding bell go off about then. So where did it vanish to?
ep 4 -	There's a clearly visible boom mike and operator standing in the shadows as Ian and the Doctor come down the stairs of the haunted house for the last time.
ep 4 -	Frankenstein's Monster is credited as just "Frankenstein".
ep 4 -	When the Daleks establish that the Doctor & co. are approaching the planet Mechanus, we see a rectangular screen in their time machine with a series of three-digit numbers underneath the main monitor, supposedly part of the machine. But when a Dalek moves in front of the screen, the numbers are partially superimposed on the Dalek!
ep 4,5 -	The actor playing the Doctor's robot double (supposedly "indistinguishable from the original") looks so completely unlike William Hartnell it's not funny.
ep 5? -	There's also a shot of the jungle on Mechanus where you can see a Dalek in the background before they're supposed to have arrived.
ep 5 -	Watch the scene where Vicki finds the TARDIS for the first time (on Mechanus). Afterwards, you can see a boom in the background. And if you keep looking at the background you can see the operator's hand pick something up off the ground.
ep 5 -	When Ian and the Doctor are carrying Vicki back to the cave, in the background is the Dalek ship, right outside the cave (instead of half-way across the jungle) - and they don't even notice it!
ep 5 -	When the Daleks are massing to attack our heroes, they pass by the entrance to their cave and continue half-way across the jungle to the entrance again!
ep 5 -	In one scene in the jungle on Mechanus, a BBC camera cruises through the background - you can see a large white '3' painted on its side.
ep 6 -	As the Doctor and Ian come back down from the roof of the city, Steven walks over to talk to them. The camera "dramatically" follows Steven around the set until a certain point where the camera suddenly jerks, we hear a soft "thunk" and then a "oooh!" from the cameraman! Stubbed his toe, methinks.
ep 6 -	There's a moment when the Doctor and co. have been first captured by the Mechanoids that the camera is jostled very obviously.
ep 6 -	When the door to Steven's "cell" drops, it bounces a few times before it closes for good.
ep 6? -	When asked to estimate the distance from the Mechanoid city roof to the ground (over 1500 feet as it turns out) Steven's first guess is a piddling 15 feet!
ep 6 -	The rope that is supposed to be lowering everyone down almost a quarter of a mile is quite slack!
ep 6 -	When Ian and Barbara are starting to climb down from the Mechanoid city roof, Barbara slips and falls head-first off the roof. Ian saves her... by grabbing her pants! He clings onto her belt for dear life and almost manages to pull her trousers off in the process of rescuing her.
ep ? -	In one scene where the Daleks are entering their time machine, you can see one lifting itself up to get over the lip at the entrance.
ep ? -	There's a scene where a Dalek is moving along on some sand, and you can see that it leaves footprints in the sand after it!
ep ? -	In one scene in the Dalek craft, you can see someone running across the bottom right hand corner of the screen - quickly, but noticeably.
ep 1-6 -	Then there's the entire interior design of the Dalek spacecraft, the bad dubs on the Robot Doctor, Barbara suddenly running over to that crumbling wall on Aridius just so that the Mire Beast can grab her, the visible wires on the bats, the misplaced sound effects, William Hartnell's ubiquitous messing up of his lines, the Visualiser that has names of Sol planets written on it although it's supposed to be able to tune anywhere, the bad accents in the Empire State Building -- I could go on forever...

The Time Meddler:
ep 1 -	The Doctor clearly tells Steven that they have landed in the 11th century, but after the wristwatch is discovered, Steven asks how it could possibly be in the 10th century.
ep 2,3 -	The reprise to episode 3 is completely different to the cliffhanger in episode 2: Steven does different things to the door, and the sheepskin rug on the bed changes completely.

Galaxy Four:
ep ? -	In the only surviving clip from this story, Peter Purves cocks up his line!

The Dalek Masterplan:
ep 1 -	The message found on the tape recorder is different from the one left by Marc Cory in the prequel episode "Mission to the Unknown".

The Massacre:
ep 4 -	The Doctor's little solo speech was unintentionally truncated, as Hartnell apparently forgot his lines.
ep 4 -	At one point, the Doctor calls Chesterton "Checkerton".

The Ark:
ep 1-2 -	Throughout the story, the actor playing the Commander appears to be wearing badly-fitting dentures!
ep 1 -	The Doctor notices Dodo's daft costume and asks her: "Have you been fruiting about in my wardrobe?" (or something that sounds very like 'fruiting').
ep 1,2 -	At the end of episode 1, Zentos says: "Take them to custody and later they will be made to suffer for the crime that they have committed." However, in the episode 2 reprise, this becomes "...they will be made to answer for the crime..."
ep 2 -	As Zentos talks with the others about the verdict, watch out for the guy on the left who doesn't know where to put his hands, as he realises that the costume designer forgot to add pockets!

The Celestial Toymaker:
ep 4 -	When the Doctor's disembodied hand plays the Trilogic game, the game pieces on each corner are all nicely lined up with the black triangles on the board. However, during the speeded-up sequences, the pieces at B and C are turned around, and are no longer aligned with the black triangles.
ep 4 -	When Cyril falls off triangle 11, he shouldn't have been electrocuted because he wasn't grounded (just as birds can sit on power lines without getting fried).

The Gunfighters:
ep 1 -	Taking it for granted that this entire episode is one huge blooper, let's move on. Given that the combatants at the O.K. Corral actually spoke with neither British nor Australian accents, we can forgive the actors portraying them - with only a disapprovingly raised eyebrow. However, their struggle to create an American accent sometimes impedes their ability to remember lines. For instance, one of the good old boys in the saloon comes out with: "Now let's get this straight. You mean you don't know where Holliday ... y-you never met Holliday either?" All that's missing is "g'day mate".
ep 3 -	After Dodo holds a gun on Doc Holliday, he flubs his line: "For the first time in my life, I have just been taken -- beaten ... to the draw". Taken out and beaten would be better.
ep 3 -	The Doctor enters the jail to tell Wyatt Earp that Steven (calling himself Steven Regret) has ridden off to find Dodo and Doc Holliday, but seems to have some trouble recalling the gender of his companion. Earp: "You mean Regret has gone after Holliday alone?" Hartnell: "No, no, my dear marshal, no, she's gone with a young man by the name of Ringo."
ep 3 -	A bulb blows at the end of this episode.

The War Machines:
ep 4 -	As the Doctor examines one of the War Machines, he passes his cloak down to Ben over the machine's gun arm. In the process, the TARDIS key falls out of the cloak's pocket, landing on the floor with a clearly audible clang! Ben picks up the offending bit of metal and seemingly tries to give it back to the Doctor, but Hartnell is too busy prattling on to notice, so Ben just leaves the key resting on the War Machine's gun arm before slinking off sheepishly.
ep 4 -	After the Doctor examines the back of one of the War Machines, he stands up and bangs his head quite badly on the top of the machine. Must have hurt -- but he carries on regardless. What a pro.
ep ? -	The story is supposed to be set in 1966 (the year the Post Office Tower opened in London). However, at one point Sir Charles mentions a date of Monday 16th July -- in reality, 16th July 1966 was on a Saturday. (The date given would place the story in either 1962 or 1973.)

The Smugglers:
ep 1,3 -	The rhyme the Doctor recites in episode 3 is different from the original rhyme heard in episode 1.

The Tenth Planet:
ep 1-4 -	During every outdoor scene in Antarctica, heavy blizzards are shown raging constantly. In reality, such blizzards are extremely rare at the South Pole, thanks to the almost total absence of precipitation (Antarctica is effectively a desert).
ep 1 -	The credits at the end of this episode spell Kit Pedlar's first name as "Kitt".
ep 1 -	The same episode's credits give Ron Grainer a name change as they list "Theme music Byron Grainer".
ep 3 -	Another credits blunder happens in this episode, where the credits mis-spell Gerry Davis's surname as "Davies". Who did the credits for this story -- Stevie Wonder??