Within the oeuvre of DreamWorks Animation, “How to Train Your Dragon” was anything but typical. So when the film went on to earn nearly half a billion dollars, director Dean DeBlois asked himself why the sequel should be any different.

“Maybe it’s because I’m a ‘Star Wars’ kid,” says DeBlois. “‘The Empire Strikes Back’ always struck me as a movie that took everything about a world and made it deeper and richer tonally. That was what I was after — that sense of fun and increased scope and richer characters and larger stakes. Our film seemed as though it occupied a world where there is more story to be told and more questions to be answered.”

Who wouldn’t be on board with that kind of vision? Except, that hasn’t been the norm at DWA, which has enormous success playing it safe with sequels, often seeing its followups out-gross the originals at the box office. (“Shrek 2” did nearly double the business of the first, earning $937 million back in 2004.)

“I think too often animation sequels seem unnecessary. They turn the same five or six characters into another adventure,” admits DeBlois, who pitched a completely different approach to DWA topper Jeffrey Katzenberg: “I told him I was interested if he would consider the idea of a trilogy, because then the first film could serve as a first act in a larger narrative on the way to an overall coming-of-age story where Hiccup would become a wise Viking chief, and we could end on roughly the same concept as Cressida Cowell’s book, explaining why the dragons disappeared.”

Katzenberg liked the idea, as did development director Greg Taylor and chief creative officer Bill Damaschke. And without going so far as to greenlight the third film, they endorsed the idea of approaching “How to Train Your Dragon 2” as the building block in a greater story, beginning with the idea of Hiccup being five years older when the new film begins.

“That way, we could avoid the problem that is often faced by sequels where you start with a character who had all his problems seemingly solved in the first film,” DeBlois explains. “Now Hiccup’s set to succeed his father as the leader of Berk. He’s been out there with (his dragon) Toothless mapping the world, discovering new lands, new tribes, new dragons.”

Though each film is designed to stand on its own, DreamWorks used another tool in its arsenal to help expand the mythology of Berk: As they had with “Madagascar” and “Kung Fu Panda,” the studio created a tie-in TV series with the same characters. But in the case of “DreamWorks Dragons,” the series was developed to extend the story of the movie, detailing the challenges the Vikings face trying to coexist with dragons. The third season will pick up after the upcoming movie and help pave the way for the final feature.

When DeBlois first came over to DWA to work on the original “Dragon” in 2009, the project was essentially a rescue mission. The studio had already spent a few years trying to do a fairly faithful adaptation of Cowell’s book series, and DeBlois and co-director Chris Sanders (with whom he’d worked on atypical toon “Lilo and Stitch” at Disney) had only 14 months to overhaul “Dragon” in time for its scheduled March 2010 release.

“Normally, it takes more than three years to make one of these,” says DeBlois, who was happy to have that entire time to focus on what audiences will see onscreen for “Dragon 2.” “As a result, I think the film looks a lot better than the first. In addition, our film is the first to showcase a whole new generation of software that has been developed at DreamWorks called Apollo.”

From Pixar to Sony Pictures Animation to DWA, all the major toon studios have proprietary software that artists use to create their films. Until the arrival of Apollo, however, DreamWorks animators had to deal with an incredibly technical interface. According to DeBlois, “In past versions, if you wanted to do something as simple as arch an eyebrow, you would have to select the eyebrow from a menu and input what degree of arch you would want, enter that numerical amount, and wait for that to render,” whereas the new system allows them to work in a much more intuitive way, using a stylus and touch-sensitive Cyntiq monitor to grab and manipulate the characters, which now render in real-time. “It allows animators to go back to working with their hands.”

Before starting on the sequel, DeBlois prepared a “board of ambitions” for himself, detailing bold and risky elements he wanted to include in the film — most of which made it in, he says. He felt empowered by the reaction to the first movie’s qualified happy ending (Hiccup survives, but loses a leg).

“When we tested the movie with that ending in place, the focus group rose to defend it,” DeBlois recalls. “I remember one kid who was only 8 years old raising his hand to say, ‘It’s sad because Hiccup lost something, but he got so much more.’ That was the intent. At the end of the day, I’d love for the hallmark of the trilogy to be one that is daring and bold, at the same time that it is entertaining and emotional.”