17-year-old Mary Katherine, or M.K., moves in with her eccentric scientist father Professor Bomba who has been searching for tiny humanoid soldiers called Leafmen. They protect the forest that Bomba lives near from wicked creatures called Boggans and their malevolent leader Mandrake. An independent young soldier named Nod decides to quit much to the ire of the no-nonsense Leafmen leader Ronin.
The queen of the forest, Queen Tara, must choose an heir to her throne and goes out to a field of leaf pods, guarded by a laid-back slug named Mub and a wannabe Leafman snail named Grub. Immediately after she chooses a pod, the Boggans attack. Tara flees the area with the pod, and though her bodyguards do their best to protect her, they are soon overwhelmed by the sheer number of Boggans. Eventually, Ronin arrives for her and the pair fly off on his hummingbird mount. They are then attacked by Mandrake and his son Dagda. Dagda is killed by Ronin, but the former shoots Tara beforehand.
Meanwhile, M.K. decides to leave after having an argument with Bomba about his research. Before she can leave, Bomba's dog Ozzy runs into the woods. While looking for Ozzy, M.K. sees Tara falling. Dying, Tara gives her the pod and uses her magic to shrink her. She tells M.K. to take the pod to a Glowworm named Nim Galuu before she dies, and M.K. joins Ronin and the Leafmen, along with Mub and Grub. Ronin discovers that Nod has entered a race against other creatures and bugs on birds. Nod goes back on a deal with a tough bullfrog named Bufo to throw the race. Before Bufo and his two henchmen can feed Nod to a snake for not throwing the race, Ronin intervenes and orders them to leave. A reluctant Nod joins him, M.K., Mub, and Grub after hearing about Queen Tara's death which Bufo overhears.
Ronin, Nod, M.K., Mub, and Grub eventually track Nim Galuu down. He then leads them down to the scroll library, where M.K. discovers Tara's brief message before shrinking her, and a message that will get her back to normal size. When Ronin leaves, Nod takes M.K. on a deer ride and they begin to fall in love. Meanwhile, Mandrake has had the Boggans bring Bufo to him, finding out the location of the pod. Mandrake goes to Nim Galuu's place to steal the pod, which, if it blooms in darkness will help Mandrake destroy the forest. He takes the pod and kidnaps Mub and Grub. Ronin scolds Nod for not being there to protect the pod. To get into Boggan territory undiscovered, M.K., Nod, and Ronin set out to Bomba's house to get some disguises, where M.K. learns that the Leafmen have deliberately been leading Bomba off their trail. Bomba sees that he has visitors and captures M.K., fainting when he sees her. M.K. marks the location of Moonhaven on a map Bomba has made of the forest before rejoining Nod and Ronin.
When they reach the Boggan land Ronin distracts the Boggans while M.K. and Nod rescue Mub, Grub, and the pod. Mandrake discovers them and orders the Boggans to stop them. M.K., Nod, Mub, and Grub escape alive, but Ronin sacrifices himself to ensure their escape. Before the full moon can sprout the pod at Moonhaven, Mandrake's bats block the light, causing the pod to begin sprouting in darkness. The Leafmen set out to fight the Boggans; M.K. tries to get help from her father by visiting his various cameras he had set in the forest. However, upon regaining consciousness, Bomba believes that he didn't really see M.K. and that he has been insane all these years, and shuts down all his cameras. He changes his mind when he sees a red push-pin that M.K. had put on his map.
Bomba is overjoyed to see that he has been right and he follows M.K. to Moonhaven. M.K. uses Bomba's iPod to make bat sounds, luring Mandrake's bats away. Meanwhile, Mub and Nim Galuu try to stop Mandrake from reaching the pod, but are unsuccessful. Just then, Ronin appears, bearing scars and bruises from the Boggans. Mandrake manages to outdo him, but Ronin is defended by Nod, who finally realizes the importance of teamwork. Before Mandrake can obtain his victory, the pod blooms in moonlight, defeating the Boggans, and sealing Mandrake into the burl of a nearby tree.
The chosen heir is the flower child who helped save Tara earlier in the film. Grub becomes a Leafman, Nod and Ronin reconcile, and Nod and M.K. kiss before M.K. is returned to her original size. After reuniting with Bomba and becoming his assistant, the human family still keeps regular contact with their small friends as they continue the research of their world.Colin Farrell as Ronin, a seasoned Leafman warrior, leader of the Leafmen, Nod's guardian and teacher, and a friend of Nod's late father.
Josh Hutcherson as Nod, a rookie Leafman warrior.
Amanda Seyfried as Mary Katherine (a.k.a. M.K.), Professor Bomba's 17-year-old daughter. She is named after William Joyce's deceased daughter.
Christoph Waltz as Mandrake, the leader of the Boggans. Waltz also voiced Mandrake in the German dub of the film since German is his native language.
Aziz Ansari as Mub, a slug, Grub's best friend and caretaker of the pods.
Chris O'Dowd as Grub, a snail, Mub's best friend and fellow caretaker.
Pitbull as Bufo, a bullfrog who works as a race fixer and a businessman.
Jason Sudeikis as Professor Radcliffe Bomba, Mary Katherine's father and a scientist.
Steven Tyler as Nim Galuu, a Glowworm, a showman and keeper of magic scrolls that tell what has occurred during the times, in a tree.
Beyoncé Knowles as Queen Tara, the Mother Nature-like queen of the forest and Ronin's childhood love.
Blake Anderson as Dagda, Mandrake's son and the Boggan general.
Judah Friedlander as Larry The taxi driver.
In 2006, it was reported that Chris Wedge would be directing an animated feature film based on William Joyce's book, The Leaf Men and the Brave Good Bugs for Fox Animation. Joyce, who had already collaborated with Wedge as a designer and producer on the 2005 film Robots, was set to produce the film. At one point, Wedge got permission to find a new home for the film and turned to Pixar, led by John Lasseter, a close friend that Wedge knew from working on Tron. When Pixar tried to close the rights for the film and start development, Fox changed their mind, and the film returned to Fox. The film was officially greenlit in 2009, under the title Leaf Men. In May 2012, Fox announced the final title for the film (Epic), its first cast details, and a plot. According to Wedge, he was not satisfied with the renaming, which was decided by the marketing department. He also expressed dissatisfaction with subtitles given to the film in some non-English countries, including the French subtitle, The Battle of the Secret Kingdom.
Although the film is based on and borrows many characters from Joyce's book, its plot has been significantly changed. Wedge explained: "But while Bill wrote a wonderful book, it is a quaint story. We wanted to make a gigantic action-adventure movie." To address online speculations about whether the film is similar to other films, like FernGully: The Last Rainforest or Avatar, Wedge said: "I hate to associate it with other movies. It is adventure on the scale of Star Wars. And it does immerse the audience completely in a world like Avatar. But it has its own personality."
The film was released publicly on May 16, 2013, in Argentina, Bolivia, Chile, Germany, Peru, Puerto Rico and Switzerland. The film was released in the United States on May 24, 2013.
Produced on a budget of $93 million, Epic grossed $107,518,682 in North America, and $160,907,952 in other countries, for a worldwide total of $268,426,634. In North America, the film earned $9.3 million on its opening day, and opened to number four in its first weekend, with $33,531,068, behind Fast & Furious 6, The Hangover Part III and Star Trek Into Darkness. In its second weekend, the film dropped to number five, grossing an additional $16,616,310. In its third weekend, the film stayed at number five, grossing $11,876,003. In its fourth weekend, the film dropped to number seven, grossing $6,284,905. While the film was overshadowed by other animated films that summer including Monsters University and Despicable Me 2, the film finished in third out of six family films that summer, and became a moderate box office success.
Epic received mixed reviews from critics. Rotten Tomatoes gives the film a score of 64% based on 119 reviews, with an average rating of 5.9/10. The site's critical consensus reads: "Though its narrative themes are all too familiar, Epic is beautifully animated and crafted with just enough flair to make for solid family entertainment." Another review aggregation website, Metacritic, which assigns a normalized rating out of 100 top reviews from mainstream critics, calculated a score of 52 out of 100 based on 30 reviews. Audiences polled by the market research firm CinemaScore gave Epic an "A" grade on average and an "A+" among kids.
Stephan Lee of Entertainment Weekly gave the film a B+, saying "The story lacks the specialness of a Pixar movie — it retreads the same eco-battle archetypes as FernGully and Avatar — but it's a perfectly appealing explosion of color for a lazy summer day." Michael Rechtshaffen of The Hollywood Reporter gave the film a mixed review, saying "Where the animated film comes up short is on the inspiration front -- despite the intriguing terrain, its stock inhabitants lack the sort of unique personality traits that would prevent them from feeling overly familiar." Michael Phillips of the Chicago Tribune gave the film two stars, saying "It's difficult to keep its story and characters, or even its visual design, in your mind's eye, in part because the five credited screenwriters overload the narrative with incident and threatening complication." Kyle Smith of the New York Post gave the film one star and a half out of four, saying "It’s not that the plot of Epic is complex; it’s just untidy. There’s a lot going on that goes nowhere." Moira Macdonald of The Seattle Times gave the film three and a half stars out of four, saying "The story's simple enough to appeal to young kids (the 8-year-old with me pronounced the movie "awesome"), but adults will enjoy the beautiful animation, whether 3D or 2D." Stephen Holden of the New York Times gave the film two and a half stars out of five, saying "As beautiful as it is, Epic is fatally lacking in visceral momentum and dramatic edge."
Epic was released on DVD, Blu-ray and Blu-ray 3D on August 20, 2013.
Danny Elfman composed the original music for the film, which was released on May 28, 2013 by Sony Classics. Beyoncé performed and co-wrote with Sia an original song, titled "Rise Up." The song was released as a digital single and as part of the digital version of the soundtrack. This is the first time that a film produced by Blue Sky Studios has not been scored by John Powell since the first Ice Age installment, which was composed by David Newman.