What novels have had a substantial real-world effect?

Sorry not RTFT, but Dicken's Nicholas Nickelby was instrumental in the decline in Yorkshire boarding schools which were profoundly abusive money-spinners. Similarly Tom Brown's School Days exposed brutal bullying in boarding schools but it took a long time for it to end.

The people who owned the rights to Roald Dahl’s work changed it in the hope of making more money and getting free press from the announcement of the changes. You can demand change as much as you want but it’s the rightsholder who decides so it doesn’t matter where on the political spectrum the demands are coming from. It’s pure capitalism.

To Kill A Mockingbird was also influential within the legal profession because of Atticus Finch.

I believe that the Harry Potter series is credited with dramatically increasing the number of children (particularly boys) reading for pleasure.

I think in the case of Mockingbird it is about how it shapes the debates about racism during the 1960s and beyond--the impact is huge partly because it is such a 'teachable' novel. It's given to teenagers across the globe to read.

Changing hearts and minds--more difficult to assess in terms of real world impact.

Very interesting @Benvenuto !

Rousseau’s Émile is the great exception - it’s not much read today in England as it’s very long and dull although it’s referred to in books on education or on literature. Basically it transformed people’s views on education from a very formal one to a more child-centred approach. I would argue that Émile makes Rousseau a “great man of history” with the caveat that he was not fitted for this by his character nor his morals & that if he lived today, no sensible person would let him near a child.

I’ve just checked on Wikipedia & not all of his ideas were apparently original - but no-one else put them forward with the impact that he did. Yes, he surfed the Zeitgeist with regards to attitude towards nature etc - but then he did a lot to create that Zeitgeist with his previous blockbuster La Nouvelle Héloïse. I’m not sure other people would have done it either - France wasn’t exactly short of Enlightenment philosophers in the 18th century but the others were to busy writing the Encyclopaedia / visiting Frederick & Catherine the Great etc to have the same impact on education. You also can’t say that Rousseau’s own actions helped the impact of his book, as he didn’t put them into practice - other people read his book & did. Even now, you could probably analyse education in Rousseau terms - the Early Years Foundation Stage feels very Rousseau, whereas SATS feel more pre-Rousseau.

For me, what makes the impact of Émile so extraordinary is that Rousseau as an author of fiction (with La Nouvelle Héloïse) is very much on the same level as Goethe with Werther or more recently Twilight & 50 Shades. None of the other texts are thought to have had a positive impact on people - yet reading Rousseau inspired people to garden & be kinder to children.

The Curious incident of the Dog in the night time sparked a lot of discussion about autism and gave some insight into the mental processes an autistic person may go through.

The night before Christmas by Clement c Moore for it's description of Santa / St Nicholas. I don't know if the 8 reindeer names were created by the author or based on folklore, but the story still has a huge cultural influence

Re We need to talk about Kevin.. it's been years so I can't remember all the details, but it created a greater empathy for a parent of a disturbed child. The thinking previously was often that the parents hadn't done enough or were emotionally neglectful.

A lot of Dickens had impact poverty policy (for better and worse)

Frank Herbert's Dune.

Its depiction of Arrakis as a "living planet" strongly influenced the growing environmental movement and concepts of ecology. It also explored themes of empire decline, the dangers of power concentration, obedience to authority, and resource control. The plot explored and integrated Middle Eastern influences, desert cultures, and dives into religious mysticism.

Some of these themes were later reflected in Star Wars and Game of Thrones.

I think the totalitarian state depicted in 1984 banned books/recalibrated words for different reasons than the censorship/language modification which happens now. In 1984 it was part of a wider means of total societal control. What we're experiencing now is to my mind more to do with the regular swings western Europe has between puritanism and permissiveness. We had our permissive era in the 90s and now we're buttoning ourselves up again.

In terms of actual change

Uncle Tom's Cabin
Black Beauty
The Waterbabies

A lot of the others were highly influential and changed viewpoints/encouraged public discussion but in terms of changes in policy/laws these three. I read Black Beauty in 4th class (traumatised on some level - still think occasionally about Ginger going to the knacker's yard) and Waterbabies in 5th class.

Yes and no. The act of censorship is the same whether one is far-left or far-right, yes. This isn’t the point. Societies around the world all indulge in the act of censorship: we don’t allow fiction or non-fiction as it depicts (for example) child sex abuse, or racially aggravated hate speech, or attacks on religious freedom. These things are apolitical to lesser or greater extents.

Elon Musk is (now) completely anti-regulation and apparently pro-absolutely “free speech” when it comes to expression of thought on his platform. Look where that’s got the world (Grok and AI-generated pornographic imagery which he’s now conceded might not be ideal). It’s hard and non-stop work deciding what to censor and what to print. I don’t think George Orwell was advocating for a world run by Elon Musks.

I wish those on the woke left would re-read 1984 and understand that its lessons applied to them just as much as everyone else. It wasn’t the ‘fascists’ who demanded Roald Dahl’s books be re-written. Orwell would be bitterly amused to find that so-called liberals are now the most dictatorial and intolerant people in Britain. They’re the ones who are trying to control what we can say and think and read. It’s the liberal-left who are stopping people speaking on university campuses. And it’s the liberal-left who are re-writing history, attacking the literary canon and ‘de-colonising’ the libraries.

God, ‘de-colonising the libraries’ is exactly the kind of phrase you’d expect to find in 1984. Orwell assumed future dictatorships would either be right-wing fascist or Stalinist Communist. Not even he imagined woke-liberal dictators!

Well put.

That's the way I'm thinking.

Some of the Victorian novels mentioned previously did contribute towards changing attitudes towards, for example, divorce or the use of climbing boys (child chimney sweeps).

Some of the modern novels cited, led to articles in broadsheets, interviews at literary festivals, dinner party conversations among the lanyard class but I'm not convinced that any of them led to (or even contributed towards), wider societal changes.

I didn't mention laws. What changed though. What did the vast majority of people think before the book came out and how did society's attitude change afterwards - you've got to have some metric for tracking change.

Like I said, it doesn't have to be about laws being introduced. It's about how we see ourselves, and it added to the debates around nature versus nuture, the ways women are made to feel responsible for family outcomes, the rise in child unhappiness, going back to work etc. I think it had an impact because it got people talking about these things. It moved the conversation, people's understanding of some big issues they maybe hadn't considered.

The book did that. Not a TV series or a documentary but a book.

I remember Lionel Shriver being absolutely everywhere in the broadsheets and lit festival circuit. No idea what her books actually influenced. What changed as a result?

I remember all three being really influential at the time. Books like that come along every so often.

Yes, it was , I guess he didn't have very refined taste:)

Fair enough. I can see that "substantial impact" can be interpreted in different ways.

What public conversations do you think they contributed to?

I think we have different ideas of "substantial impact", that's all. I think these three moved the dial on significant social issues and they did it from people buying the books and talking about them, investigating the issues, coming to new positions on the points they made.

I agree they didn't overthrow regimes or bring in new laws but they did have a huge impact on people's actual lives.

I don’t think there would be many novels that will have had an immediate substantial real-world effect. They’re novels. Their influence might not be appreciated until decades after the author has died, for example. The impact could be on writing styles (Austen was the first to break the fourth wall); on feminism by introducing small but significant new ideas to their readers; on empire by exposing readers to the horrors that go on in places unknown (same goes for many if not most books mentioned here); and so forth.

I don’t think the OP is asking for major and immediate impacts in real time. She asked for substantial effects. That’s really any book that hasn’t sunk without a trace, and that’s been read by many who have felt impacted for one reason or another.