When Deadpool & Wolverine, starring Ryan Reynolds and Hugh Jackman, made $438m worldwide on its opening weekend, Marvel executives must have felt as if Christmas had come early. It is Easter, though, that deserves part of the credit: Easter eggs, that is, those fan-centric surprises with which the modern blockbuster is sprinkled, or in this case cluttered. They take many forms: unpublicised cameos, in-jokes that only franchise devotees would clock, surprise scenes stowed away in the end credits, abundant references to other movies, even allusions to controversies on the sets of other movies. The Easter eggs in Deadpool & Wolverine belong to all these categories and more. There are so many, in fact, that it’s tempting to ask: which came first, the movie or the eggs? Whatever the style of Easter egg, the point is the same: to encourage, flatter and reward the deepest possible level of fan engagement and to keep completists coming back for more. One downside is that this can be alienating for anyone not up to speed with the latest Marvel minutiae. “I was lost from the first minute, when some time cops try to stop Deadpool’s plan to resurrect Wolverine to stop the apocalypse,” wrote Jonathan Dean in the Sunday Times. “To make that make sense, you need to have seen both series of the Disney+ show Loki, which I gave up on after two episodes.” In other cases, the supposedly hidden content is merely sub-par rather than incomprehensible, such as the desultory mini-scene that ends the otherwise excellent Inside Out 2 after an eight-minute credit roll. Still, I am a firm believer in waiting until the very end of a movie before leaving the cinema, partly because of the gems buried in the credits: the thank-yous containing the names of other film-makers from whom a director sought counsel during production, or the jokes slipped into the end titles of spoofs, such as 1984’s Top Secret!, where the occupations listed descend from the legitimate (“focus loader”, “focus puller”) into gobbledegook (“clapper clapper”, “flipper flapper”). The tradition of hidden messages is nothing new. “Easter eggs have always existed in works of art,” says Ashlyn Chak, a culture reporter for the South China Morning Post. “There’s Hans Holbein the Younger’s 1533 painting The Ambassadors, in which a human skull can be seen only from a particular angle, or the theories surrounding Adam’s extra rib in Michelangelo’s The Creation of Adam. “With films, it makes the viewer feel as if there’s a secret language between them and the film-makers. I prefer it when the Easter eggs aren’t too obvious or abundant; even better if I don’t notice them on the first watch. Those ‘aha!’ moments feel more precious than just being shown a joke that nearly everyone gets – what’s the fun in that? Film lovers like to be challenged instead of babied.” A true Easter egg needs that element of concealment, like the secret tracks that arrived only after minutes of silence at the end of a CD, or the messages scratched into the run-off grooves on Smiths records. In extreme cases, the destruction of the object itself may be required to expose the secret. If King Charles were to pick apart the jacket made for him when he was a prince by Alexander McQueen, he would be able to confirm whether it does indeed feature an insulting message sewn into its lining, as the late designer claimed. Superhero movies have inflamed the public’s appetite for Easter eggs, but they are not restricted to Hollywood. In arthouse cinema, where they tend to be referred to as “allusions” rather than anything chocolate-related, Peter Greenaway has long secreted codes and clues in his densely layered work. His 1988 comic mystery Drowning By Numbers features numbers from one to 100 planted in the images somewhere on screen, which at least obviates the need to check your watch to see how much of the film is left. It’s at the multiplex, though, where the trend has been over-egged. Until Deadpool & Wolverine came along, Steven Spielberg’s Ready Player One, a film that sinks beneath the weight of its pop-culture references, was the nadir for the Easter egg craze. In that picture’s defence, there was method in its too-muchness. It wasn’t merely full of Easter eggs – its characters were actively hunting for them. But it got one detail wrong. While the film was correct to say that the origins of Easter eggs lie in the video-game industry, it was not in fact the 1980 Atari game Adventure that kicked off the trend. That game did feature an early Easter egg, in the form of a surreptitious credit for its creator, Warren Robinett, who rebelled against the industry policy of not acknowledging individual designers. Atari’s Steve Wright first mentioned the term “Easter egg” in print in 1981 and seized on its value as a marketing tool. But the original Easter egg hatched in 1973 in the game Moonlander, in which a specific manoeuvre enabled players to access a hidden lunar branch of McDonald’s. “It’s a fucking McDonald’s?” joked the video-game expert Critical Kate in a 2021 vlog. “You’re telling me that all these programmers who were sticking it to the man in their own little triumphs against anti-creator corporate values were beat to the punch by a tribute to the most pervasive corporate symbol on the planet?” This was nothing if not an early sign that Easter eggs can make you sick. The LaserDisc format had experimented with special features, but it was with the success of the DVD market that the idea took off. Films involving mysteries and puzzles in some way, such as National Treasure or the Harry Potter movies, lent themselves to labyrinth-like DVD menus. Budding cryptologists had their work cut out accessing Easter eggs without scrambling their brains on the DVD of Christopher Nolan’s anti-clockwise thriller Memento. A fiendishly tricky menu hinging on memory tests eventually revealed the coveted extras, one of which was a version of the film in chronological order. “I always associated Easter eggs with a cinematic or TV version of the secret track on an album,” says the journalist and author Tom Ellen. “Something cleverly squirrelled away within the actual mechanics of the format that you could only find through word of mouth or sheer luck.” Take the DVD of Armando Iannucci’s news spoof The Day Today. “If you selected a menu and then waited a certain amount of time without selecting anything else, a ‘secret track’ would start playing in the form of a new interview between Chris Morris and the useless correspondent Peter O’Hanraha-hanrahan, played by Patrick Marber. That, to me, was the epitome of the Easter egg, rather than an in-joke placed in the movie or show itself.” Ellen isn’t averse to in-jokes. “Growing up, I was a big fan of Kevin Smith’s View Askewniverse films and I used to love hearing a throwaway reference in Mallrats or Chasing Amy to a character from Clerks. It made you feel like you were part of the universe, part of Kevin Smith’s little gang.” Mike McCahill, a film critic and an expert on Indian cinema, cites an example from Bollywood. “When Salman Khan and Shah Rukh Khan were reunited via their cameos in last year’s Pathaan and Tiger 3, the room erupted,” he says. “Partly because the movies opened up into a dialogue about these stars, their bodies of work and our relationship with them. If these scenes and moments are anything beyond a neat treat, I think they represent a shared knowledge and a shared love, even. The audiences I’ve been in adore them – they’re like the sweets thrown out to the crowd at a pantomime.” Given the success of Deadpool & Wolverine, Easter eggs are likely to remain a staple item on the menu. “I grew up watching Wayne’s World, which operated on much the same lines,” says McCahill. “But I fear, after Deadpool & Wolverine, every big Hollywood movie is now just going to be a series of meme-able moments. Directors should be storytellers, not winkers. And as with their chocolate equivalents, Easter eggs should be consumed in moderation.” As Critical Kate points out, 21st-century Easter eggs haven’t developed very far beyond that 1973 shout-out to McDonald’s in Moonlander: “Today, this is what most Easter eggs are: brands hidden in the background that we freeze-frame so we can see how many we recognise and then write a blog post about it.” Nevertheless, they tap into twin desires that remain achingly human: our need for a shared community; and the hope that there is a secret that will finally confer meaning on to our lives. That may well be the case. Just don’t expect to find it behind Reynolds’s smirk. Deadpool & Wolverine is in cinemas now