Doctor Who is, famously, a show for kids big and small. But in its mission to appeal to both children and grown-ups, the BBC sci-fi show frequently has to make calls on what content is appropriate for all ages.

Sometimes, an episode or a particular scene will push the limits of what you can get away with at Saturday teatime, drawing the ire of the easily offended. From acid bath deaths to dodgy casting decisions, these are some of the show's most controversy-courting moments.

1. A painful afterlife – in 'Dark Water'

BBC

It's often the job of a full-blooded TV drama to disturb and provoke, but many thought Doctor Who went too far with its ghoulish series eight closer 'Dark Water', which posited the blood-curdling idea that, when we die, we remain horribly, unimaginably conscious.

Add to that Missy's plan to use the world's corpses to make Cybermen and Danny Pink being killed in a car accident, and you've got an episode that was as loathed as it was loved. Many lauded its bold, mature tone, while others lambasted it for its morbid, troubling themes.

With 124 complaints recorded, the BBC went on the defensive, issuing a statement where they stressed that they stood by the episode. "Doctor Who is a family drama with a long tradition of tackling some of the more fundamental questions about life and death," it said. "We were mindful of the themes explored in 'Dark Water' and are confident that they are appropriate in the context of the heightened sci-fi world of the show."

So there.

2. The Doctor drowns – in 'The Deadly Assassin'

BBC

Of all the foes the Doctor faced off against in the 1970s, few were as formidable as Mary Whitehouse. A dogged campaigner against sex, violence, bad language and anything else that was interesting on TV, she headed up the National Viewers and Listeners Association, a group of God-fearing, fuddy-duddy curtain twitchers who would regularly blast the BBC and ITV for peddling filth and moral depravity.

She'd always had a beef with Doctor Who and its brand of teatime-friendly horror, but it was with the 1976 story 'The Deadly Assassin' that she saved her most indignant ire.

The cliffhanger to episode three featured a character attempting to drown the Doctor, and that was enough for the NVLA to scold the programme for including "shots which could only be described as sadistic".

Such was the influence that Whitehouse and her followers wielded at the time that when the episode was eventually repeated, that final shot of the Doctor's submerged head was edited out. Producer Philip Hinchcliffe was edged off the show shortly after, with replacement Graeme Williams instructed to dial down the violence.

3. Problematic casting – in 'The Talons of Weng-Chiang'

BBC

Hiring a white actor to play a character of colour really was A Thing in the 1960s and 70s. James Bond did it with Dr No (Joseph Wiseman was Canadian, not Asian), Laurence Olivier did it on stage and in the movies (blacking up as Shakespeare's Othello) and Doctor Who did it, casting the resolutely Anglo-Saxon John Bennett as the Japanese stage magician Li H'sen Chang (and yes, there were prosthetics involved).

Although it screened without controversy in 1977, 'The Talons of Weng-Chiang' has since been damned by some fans for its dodgy casting decisions. "It represents Doctor Who at its very worst," one fumed in 2016, "with a stunning amount of racism, an actor in yellow-face, and a plot drawing from an extremely racist caricature".

4. Cyber-violence – in 'The Tomb of the Cybermen'

BBC

Is Doctor Who too violent and scary for kids? It's an oft-asked question, and in 1967, 'The Tomb of the Cybermen' prompted the BBC to screen a discussion on the issue on the show Talkback.

Writer Kit Pedler was invited on to debate with a group of bothered parents who thought the story was too horrific (particularly the scene of a man being electrocuted and the bit with white goo oozing from a dead Cyberman's chest).

Host David Coleman seemed more amused than concerned about the whole thing though, quipping, "perhaps it's too scary for grown-ups!"

5. Gangs of San Francisco – in the TV movie

FOX

When Doctor Who returned in 1996 after seven long years away, it was as a super-slick US/UK co-production. But the American side's idea of a freshly grown-up Doctor Who didn't quite square with the UK's and when the TV movie was aired on BBC One, it was with over a minute's worth of cuts.

The Beeb decided to chop out a sequence featuring a group being fired upon by a gang with semi-automatics (this was only three months on from the Dunblane tragedy) as well as some of the gorier details of the Doctor being worked on in an operating theatre.

The scenes were restored for the DVD release, but their inclusion meant that, for the first time ever, a Doctor Who story was slapped with a '12' certificate.

6. The 'gay agenda' – in 'Deep Breath'

BBC

Ever since Russell T Davies introduced omnisexual shagmonster Captain Jack Harkness to Doctor Who, the programme has been weathering idiotic accusations of having a 'gay agenda' (whatever that means).

In 2014, Peter Capaldi's first episode 'Deep Breath' featured the return of Silurian Madame Vastra and her human wife Jenny Flint. Though they'd been seen in four other episodes, 'Deep Breath' would be the first time the two locked lips on screen and that proved too much for some delicate viewers.

Six complained to Ofcom and three to the BBC, stating that the show was "promoting homosexuality". Weirdly enough, they didn't seem too troubled by the fact it was two different species snogging each others' faces off.

7. The Doctor turns murderer – in 'Vengeance on Varos'

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The primary appeal of the Doctor is that he values his wits over weapons, and that life, all life, is deeply precious to him. It's the heart of the Doctor that fans hold dear, so when he acts out of character it can rock our world.

Colin Baker's incarnation, with his bullish manner and waspish tongue, wasn't the cuddliest of Doctors. But being a bit sarky to Peri was the least of his off-character offences, such as in this 1985 story when a couple of Varosian guards fall into a vat of acid (which, by the way, is partly the Doctor's fault) before he quips: "Forgive me if I don't join you."

Not only was the acid a particularly grisly way to die for a teatime sci-fi drama, but the fact that the Doctor seemed not just unconcerned but actually amused drew a storm of complaints.

8. Plastic policemen – in 'Terror of the Autons'

BBC

Killer troll dolls, deadly plastic chairs and Autons disguised as policemen… There's little doubt that 1971's 'Terror of the Autons' would have sent tiny Doctor Who fans scurrying behind the settee, but it all proved too much for Baroness Bacon who, in the House of Lords no less, asked whether the show was too frightening.

"I wonder what has happened to Doctor Who recently," the Labour peer grumbled, "because many children must have gone to bed and had nightmares after seeing the recent episodes."

Baroness Bacon died in 1993, but we can only imagine how she'd have felt seeing the Weeping Angels.

9. The 'blowjob gag' – in 'Love & Monsters'

BBC

Russell T Davies' episode broke all kinds of rules when it was broadcast in 2006. Scheduled to give stars David Tennant and Billie Piper a much-needed breather, it barely features the Doctor or Rose, focusing instead on Marc Warren as the sweetly geeky Elton Pope.

But most radical of all, and the moment that sent some fans into a froth was the gag at the end when we see Elton's girlfriend Ursula, her face encased in a paving slab.

"It's a relationship, of sorts, but we manage," Elton says, before adding. "We've even got a bit of a love life."

It might have gone over the heads of little ones, but every adult watching recognised what we going on here. And all at 7pm on a Saturday evening. Cue outrage!

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