Matilda the Musical kicks off the London film festival as Netflix banks on Roald Dahl

Nerves are always high on the opening night of the London film festival. But when this year’s edition begins on Wednesday, it won’t just be the cast, crew and British Film Institute bigwigs who anxiously await audience reaction.

The world premiere that kicks off proceedings is Roald Dahl’s Matilda the Musical, released in the UK by Sony Pictures International and which marks a first opportunity to see the fruits of Netflix’s most expensive content deal to date: the back catalogue of the children’s author.

The streaming service bought the rights to Dahl’s works for £370m early last year and assigned a production budget of $1bn (£903m to cover the licensing deal and future projects. TV shows in the works include a Taika Waititi series set in the Charlie and the Chocolate Factory universe and an animated version of The Twits.

Films set for release next year include Wes Anderson’s version of the short story collection The Wonderful Story of Henry Sugar, starring Ralph Fiennes and Benedict Cumberbatch, as well as Wonka, an origins story about the factory mogul, starring Timothée Chalamet and written and directed by Paddington’s Paul King.

Sam Mendes’s live action James and the Giant Peach, adapted by Nick Hornby, will start production soon.

But in launching with Matilda, Netflix has put the most prized asset in its new portfolio front and centre. Worldwide sales of Dahl’s 1988 novel about a young girl with telekinetic powers who battles her philistine parents and a hammer-tossing headmistress have topped 17m, and since 2016 it has outsold all his previous work.

Its girl-power message – as well as a relative absence of extreme grotesquerie – mean it is the Dahl story that most aligns with the tastes of today’s readers, and their parents.

Related: Roald Dahl’s universe might not be a golden ticket for the writer’s fans | Rebecca Nicholson

For Matthew Warchus, director of the new film – as well as the acclaimed stage show on which it is based – Dahl’s appeal is more universal. “He remembers what childhood feels like,” says Warchus, “the light and the dark of it, and understands the way that our child’s-eye view of the world never completely leaves us.”

The musical debuted at the RSC in Stratford-upon-Avon in 2010 before moving to the West End and Broadway, where it won seven Oliviers and five Tonys. An international tour ran between 2018-2020 and productions have also appeared in Korea, Japan and Australia.

The challenges of making a stage play inspired by a book that is vehemently pro-literature and anti-screen have not been lost on Warchus. “Adapting anything is a paradoxical process of respecting and rejecting. You are fuelled by love of the source material, but you have to take a new journey with it – sometimes you have to let go and turn your back on the source completely.”

Warchus has reteamed with writer Dennis Kelly and lyricist Tim Minchin for the film, but not all the original team return. Bertie Carvel – who broke through with his formidable Miss Trunchbull – has been replaced by Emma Thompson, after a period in which Ralph Fiennes was attached to the role. Bond star Lashana Lynch is the sympathetic librarian, Miss Honey, and Stephen Graham and Andrea Riseborough are Matilda’s slovenly parents.

Disney paved the way for acquisitions of major cultural intellectual property assets when it bought Pixar in 2006 for $7.4bn, Marvel in 2009 for $4bn and Star Wars three years later for a similar price.

Although all acquisitions raised eyebrows at the time, profits across each franchise swiftly vindicated the decisions and inspired streaming services to follow suit.

Last May, Amazon paid $8.45bn for MGM, which owns franchises such as James Bond and Rocky. With hit show The Lord of the Rings: The Rings Of Power, the streamer is currently reaping the dividends of a $250m deal struck in 2017 to acquire TV rights to the works of JRR Tolkien.

Until 2021, Netflix’s strategy was different: offering auteurs such as Martin Scorsese, Alfonso Cuarón, Noah Baumbach and Jane Campion almost limitless funds to indulge passion projects and score Oscar nominations, while also making original mainstream series ripe for conversion into valuable properties, such as Squid Game, Stranger Things and Bridgerton.

The Dahl deal signals a shift in direction to help Netflix fend off competition from Disney+, Amazon and HBO Max by seeking to plug a gap in the market left by the ailing Harry Potter universe.

At the time of the purchase, Netflix promised “the creation of a unique universe across animated and live-action films and TV, publishing, games, immersive experiences, live theatre consumer products and more”.

Dahl’s books have been translated into 63 languages and sold more than 300m copies. Luke Kelly, grandson of the author who died in 1990, said he hoped the deal would mean Dahl’s work would “reach even more young people and families around the world”.

He also assigned a portion of proceeds from the sale to establish a charitable trust to champion children’s health, anti-hate and anti-racism. Dahl’s son, Theo, developed hydrocephalus, and his father pioneered a radical new valve to help treat the condition, which was used by many thousands of children. The death of his daughter, Olivia, aged seven, from measles, also led Dahl to be a prominent figure in the drive for nationwide uptake of the measles vaccine.

In 2020, the Roald Dahl Story Company apologised for antisemitic remarks made by Dahl over the course of his life.

The London film festival runs from 5-16 October and includes simultaneous screenings and events at venues nationwide. Galas include the Knives Out sequel, Glass Onion, Baumbach’s Don DeLillo adaptation White Noise, Jennifer Lawrence as a brain-injured soldier in Causeway and Sam Mendes’s Empire of Light, starring Olivia Colman.

• Roald Dahl’s Matilda the Musical screens at the London film festival on 5 October and is released in cinemas on 25 November.