CARLSBAD, Calif. >>

You might call it Lego on steroids.

From the moment young kids are greeted in the hotel lobby by a towering Lego wizard who stages a surprise light show, to when they crawl into their bunk beds and gaze up to see a shooting star, they are transported to a medieval castle inhabited by more than 2,000 Lego-­crafted characters.

And that’s even before a visit to Legoland next door.

Last month, the Carlsbad theme park debuted the 250-room Castle Hotel, its second onsite hotel. The latest lodging project capitalizes on the broad appeal of all things Lego — from licensed films and video games to the brand’s toy sets and its familiar swivel-armed brick characters.

Legoland’s parent company, British-based Merlin Entertainments, is also embracing a savvy business strategy honed decades ago by entertainment behemoth Disney: Build a hotel at your theme park and they will come.

Globally, Legoland has eight branded hotels, most of which opened over the last six years. By comparison, Disney boasts 37 that it owns and operates at its theme parks, with nearly half of those at Walt Disney World in Florida. In Anaheim, work is expected to start this year on a new 700-room luxury hotel, which will be the Disneyland Resort’s fourth theme park hotel.

Universal, which for years did little to expand its hotel portfolio, has been ramping up development in recent years, while the SeaWorld-branded parks have no hotels of their own.

“As a professor of the industry, I’ve always thought the hotels made sense and not just for the reason it is copying the most successful competitor in the marketplace,” said Martin Lewison, a theme park expert and business management professor at Farmingdale State College in New York. “Having a hotel makes the park feel more like a resort, which are popular because everything is taken care of you and you get all those characters in your room.

“And it’s definitely worth noting you can charge a lot more for a room that has all the bells and whistles than the Days Inn down the street.”

Nightly rates at the Castle Hotel are expected to range from a low of $205 to the $400’s during the peak season.

The design of the Castle Hotel is a creative blend of Lego-building artistry, whimsy and a generous dash of humor. Take, for example, a royal throne that doubles as a whoopee cushion and emits fart noises and a jester door that tells bad knock-knock jokes.

Everything about the hotel, from the Dragon’s Den restaurant to the knight-, princess- and wizard-themed rooms, is designed around a simple storyline created to captivate Legoland’s key demographic — children. The narrative is that the bad knights, many of whom are hiding in plain sight throughout the hotel, weren’t invited to the upcoming grand tournament, and they’re doing everything in their power to sneak in.

“In the knights and dragons rooms, the headboard looks like stained glass when you turn on the lights, almost like a glass mosaic piece,” explained Keith Carr, Merlin Entertainment’s project director for the Americas. In the wizard rooms, you feel like you’re in a wizard’s office, potion bottles lit from within and Lego owls in the corner overseeing the action. “It’s like painting the story and making you feel like you’re living inside a medieval castle.”

The principle goal, though, says Black, “is to transport you so you don’t feel like you’re staying at a regular hotel. It gives people the opportunity to continue the theme park experience well after they leave the park.”

Designers were fastidious in scaling the toys to real-life proportions. For example, the brick motif on the castle exterior and on the interior wallpaper is exactly 25 times the size of a toy Lego piece.

Bryan Brandow, whose wife and two young children traveled from their home in Fremont, Calif., to vacation at Legoland, said staying at the resort was all about the “fun factor” and the ever-present Legos, but convenience was also a huge inducement.

“It was definitely binging on Lego for a few days,” said Brandow, whose sons are 7 and 6. “I got the sense my kids would want to live there.”

“If a guest is only going for a day they’re only paying for parking, admission, something to eat and souvenirs,” said theme park blogger Todd Regan, who founded the Disney-focused micechat.com. “But with a resort you get two extra meals a day, the second day’s admission, and the hotel stay, and that’s a lot of extra revenue. So it’s a great bet for theme parks to build hotels.”