After proving to be the go-to franchise for hands-on play, a must for all children and children-at-heart, Lego expanded the brand to include amusement parks, film and television, and even books. Since 1997, it's also conquered the world of video games.

Lego Marvel Super Heroes: Awarded 9/10 by IGN, who called it "the best thing to happen to Marvel games since 2006's Marvel Ultimate Alliance."

Lego Jurassic World: The best-selling game of July 2015, beating giants like Batman: Arkham Knight, FIFA 15, and Call of Duty: Advanced Warfare.

Lego Batman 2 - DC Super Heroes: Praised by Metro for its "fine balance of drama and humor, excellent narrative and gorgeous graphics" and further calling it "the best Lego game to date."

But how have Lego games become so popular? What's the secret?

Franchise Fever

Lego hit the ground running with Lego Island and cemented its place as a gaming heavy-hitter with Lego Racers, Lego Creator, and licensed properties like Indiana Jones, Star Wars, and Harry Potter. The latter is where the company really gained ground on rival developers, giving gamers solid tie-ins to their favorite films.

Movie-related games typically bomb. Spider-Man 3 was full of glitches; Wreck-It-Ralph, considering it was based on a film about games, was massively disappointing; and the Catwoman game at least reflected the awfulness of its film counterpart.

Lego, however, manages to buck this trend, time and time again.

This is all about staying true to the brands; doing them justice by knowing what fans really want. That means the game developers aren't just working to Lego's remit, but also making decisions based on their own fandom and knowledge of their peers. Mark Warburton, game producer for TT Games (a British subsidiary of Warner Bros. Interactive Entertainment that is currently producing games exclusively for Lego) says:

"It helps us to be bigger fans of these brands every time. We make the games that we, as fans, want to see. What we have to do is marry those two things together -- the Lego and our fandom and put it together into a game."

Incorporating licensed franchises came as a result of Lego trying to defend their intellectual property, trying to put the case forward that no other companies could create building blocks that resemble their signature creations. It was in an effort to eliminate competition, and "Lego clone" companies -- brands whose construction blocks are compatible with Lego -- weren't happy.

The courts didn't side with Lego, but the company cornered the market by acquiring the rights to produce construction sets for creative industry names like Star Wars, Marvel, and Indiana Jones. Their nearest competitor, Mega Bloks, followed suit, picking up the license for Spongebob Squarepants when Lego dropped it, and further acquiring brands like Barbie, Halo, and World of Warcraft.

Lego recently went one step further, however. Lego Dimensions (2015) combined franchises; intermingling characters, worlds, and ideas into one cohesive plot, supported by toys-to-life level packs.

Frankly, it was an ideal notion for a generation that begs for franchise crossovers. Doctor Who and Sherlock; Star Wars and Star Trek; Marvel and Disney: these are all fodder for fans. A licensee creating an official product that ties these universes together was bound to be financially successful… but perhaps not critically.

Fortunately, Dimensions garnered positive reviews from critics and Lego aficionados.

Heroes Arrive in the Nick of Time

National Public Radio's Chana Joffe-Walt seems to have defined the key to this success:

"Sales of these products have been huge for Lego. More important, the experience has taught the company that what kids wanted to do with the blocks was tell stories. Lego makes or licenses the stories they want to tell."

Lego, then, pinpointed one reason Marvel is so well-loved: It's set in a single world, with heroes and villains all existing in the same universe. 2013's Lego Marvel Super Heroes has an original storyline featuring well-known locations (such as the SHIELD helicarrier and the super-villain prison known as the Raft), open-world gameplay, and 180 playable characters, all with different skill- and power-sets.

These characters included ones most casual fans will know -- Iron Man, Captain America, Thor, the Hulk, and Spider-Man -- as well as more obscure heroes and villains like Mastermind, Union Jack, Kurse, Nova, and M.O.D.O.K. Fans appreciate this depth of knowledge of the source material, and further cheeky nods to fandom -- including Deadpool breaking the fourth wall by narrating missions, and the numerous appearances of Stan Lee, creator of countless Marvel characters.

The inclusion of Marvel Studios' Agent Phil Coulson is also a positive sign of Lego's brand awareness. It's an example of their ability to produce games in a seemingly-paradoxical, timely-yet-timeless manner.

If you look at the firm's more recent releases, they're all franchises with significant mileage, but the games themselves coincide with peaks in popularity. Lego Marvel Super Heroes hit shelves shortly after the Avengers movie, at the same time that the Iron Man trilogy drew to a close. A follow-up, Lego Marvel's Avengers, came last year, after the successes of Captain America: The Winter Soldier and Guardians of the Galaxy, and in the run-up to Avengers: Age of Ultron.

The Marvel Universe shows no sign of slowing down, and neither does the Jurassic Park franchise, reawakened by Jurassic World (2015), which spawned a Lego game counterpart.

Similar popular film tie-ins include The Hobbit (released 2014, between the second and third movies), Batman 2: DC Super Heroes (released in 2012, when hype for The Dark Knight Rises was at its height), and The Lego Movie-Videogame, based on the company's own hit film, both of which were released in 2014.

Star Wars, too, has remained a mainstay, with a take on The Force Awakens hitting shelves next month and also filling fan desire to connect the dots between that movie and 1983's Return of the Jedi.

Brand Dimensions

But it's not enough to stay loyal to the values of other properties: Lego's secret to success is staying true to its own values as well -- namely fun and humor. The latter, in particular, makes the series distinctive and praised.

Most importantly, the company use humor without making light of the franchises, meaning fans don't feel like they're being patronized or made fun of.

The Lego name is synonymous with entertainment for all ages, so physical block kits come in all shapes and sizes (and prices!). That accessibility spreads to its video games, meaning a family can enjoy a storyline together.

While Mega Bloks has aligned with decidedly adult franchises like Call of Duty alongside child-friendly ones like Hello Kitty, Lego has specified brands that contain adult themes but don't exclude any potential audience demographics: adults might ponder the ethics of cloning when playing Jurassic World, and kids can marvel at some awesome dinosaurs. Or vice versa.

Incorporating hands-on Lego gaming is an added way of reinforcing its own brand. Lego has successfully sold toys since 1949: seeing the popularity of Amiibos, Skylanders, and co., the Lego Dimensions' starter pack included the main game, a toy pad, and level pack figures, Batman (plus Batmobile), Lord of the Rings' Gandalf, and The Lego Movie's Wyldstyle.

The most important element, however, was the Lego Gateway, a portal you had to build using Lego bricks. GameSpot said:

"In any game within the toys-to-life genre, there's sometimes an unspoken question: is this also a great toy or just a great game? In LEGO Dimensions' case, the answer is easy: it's both… LEGO Dimensions works unquestionably, unequivocally, as both a toy and a game, and it feels like the high point of the many LEGO titles that have come before it."

Further level packs are available from a number of different franchises, new and old, including The Simpsons (especially popular in their Minifigures range), Back to the Future, Scooby-Doo, The Wizard of Oz, and their latest license, Doctor Who. The latter especially encapsulated the spirit of the show, with regeneration -- which sees a change of lead actor every few years, keeping the show fresh -- playing a key part. The inclusion of different TARDIS interiors, the time-space ship used by the Doctor, proved a particular hit.

These cater to nostalgia, but neither pander to nor rely on it.

Lego has also established a particular look for characters and style to worlds, bypassing the race for superior graphics. You know what you're going to get with Lego. And that's reassuring and refreshing.

Success: Brick by Brick?

Star Wars: The Force Awakens is next to get the Lego treatment, and after that . . . who knows? More Star Wars titles are likely, as is further releases for DC and Marvel Comics (Guardians of the Galaxy seems most likely).

Either way, Lego deserves its standing as one of the best gaming giants.

What do you think is the key to its success? What franchises do you hope are next? And what's your favorite Lego game?