It’s not enough to have the biggest boat – you have to win the laser-tag arms race, too.

When it hits the water in April 2018, the world’s largest cruise ship will be five times the size of the Titanic by volume and hold 2,774 staterooms on 16 guest decks. Royal Caribbean’s latest effort to awe cruisers – and, it seems, make shore excursions obsolete – Symphony of the Seas will offer robot bartenders, a 10-storey-high slide, and a duplex family suite with its own movie theatre and floor-to-ceiling Lego wall.

Oh, and a glow-in-the-dark laser tag arena that Royal Caribbean says is the largest at sea.

“We set out to create a new level of vacation adventure and deliver the ultimate escape for families of all shapes and sizes,” says Michael Bayley, president and chief executive officer of Royal Caribbean International.

Norwegian’s new cruise ship boasts outdoor go-karting, laser tag and water slides

The company also owns the runner-up ships in the size category: Harmony of the Seas, which was launched in 2016, is the same width and length. But it has a gross registered tonnage – which measures the volume of enclosed space on a ship – of 226,963 versus Symphony’s 230,000. In other words, Symphony has more stuff.

“This phenomenon of having these escapist on-board activities that nobody else has, has been going on for a few years,” says Maggie Rauch, director of research for travel and hospitality research firm Phocuswright. Cruise companies are trying to dazzle new guests as well as get repeat cruisers to open their wallets wider on board.

Nine things cruise newbies need to know before walking the gangplank

Some of the new ship’s most lavish features are aimed at its smallest guests. The 1,346-square-foot Ultimate Family Suite has a slide that runs from the kids’ room to the living room, a wall devoted to Lego play, a wraparound balcony with a kid-friendly pool table climbing feature, a full-size hot tub, and a theatre-style TV room, complete with popcorn machine and multiple gaming systems.

Royal Caribbean hasn’t announced the price of the two-bedroom suite yet, but says that it can accommodate eight guests. (Rauch points out that one fancy suite may not make much money for Royal Caribbean – but it might be social-media gold. “If a family is posting videos of their kid sliding down from their bedroom into the living room, that is free marketing,” she says.) It also comes with a dedicated Royal Genie – the cruise company’s version of a private butler.

This phenomenon of having these escapist on-board activities that nobody else has, has been going on for a few years
Maggie Rauch, director of research, Phocuswright

The Genies are human, unlike the bartenders who will be working at the Bionic Bar, already a fixture on Royal Caribbean’s three other Oasis-class ships. Made by Italian firm Makr Shakr, the mechanical mixologists can muddle, shake, strain, and serve cocktails made from any combination of 30 spirits and 21 mixers. (The robots work in pairs and on other ships have such names as “Mix” and “Mingle” and “Shaken” and “Stirred.”)

Royal Caribbean is also giving its 10-storey Ultimate Abyss slide a repeat performance. On Harmony of the Seas, guests ride a mat down the sculptural purple tubes. On Symphony, it will end on the Boardwalk – one of the seven “neighbourhoods” that break up the immense ship.

The ship will feature beefed-up live entertainment, reviving its at-sea version of Hairspray and adding Flight, a Royal Caribbean original about the history of air travel. A new high-diving and acrobatics show will make its debut at the open-air amphitheatre. There’s even a hi-tech ice-skating show. That’s in addition to the 20-plus restaurants, comedy club, watersides, surf simulators, zip-line, mini-golf course, and more.

World’s largest cruise company debuts first ship for Chinese market, targeting 83 million passengers

Symphony will spend the summer cruising the Mediterranean; in November it will move on to Miami, its base for weeklong trips through the eastern and western Caribbean.

Cruisers should find a smoother boarding experience, too – Royal Caribbean will let them check in and upload a selfie to the brand’s new mobile app, then go straight to their cabins after passing through security. Finding their way off might prove to be more difficult.