As long as children have played with dolls and action figures, the rules have always been loose. Luke Skywalker can interact with Barbie without Mr Potato Head raising an eyebrow. But with computer games, kids are bound by the rules of the console. You can't drop Lara Croft into Call of Duty: Black Ops.
Which is why, even as computer games became a dominant medium of play for millions of children, action figures have remained immensely popular, with companies such as Disney cashing in on characters such as Buzz Lightyear and Lightning McQueen.
In 2011, the gaming giant Activision saw the potential in combining action figures with console games with its best- selling series Skylanders. It features dozens of collectable characters embedded with data chips which allowed kids to play as different characters, save their progress on the figures and even take them around to friends' houses to play. In 18 months this combination of toys and console gaming has become one of the most valuable franchises in the market.
Unsurprisingly, other entertainment multinationals are keen to get in on the act. In June, Disney Infinity will compete with Skylanders in the toy-video-game crossover market. With its vast collection of household-name characters, the House of Mouse is hoping its new title will bring together fans of everything from Pirates of the Caribbean to The Incredibles – not to mention characters from its recent acquisitions, Marvel Studios (home of Spider-Man, Hulk) and Luscasfilm (Star Wars, Indiana Jones).
Is it a stroke of genius bringing Disney characters to life in a new way, or just big business maximising value from recent acquisitions?
If Disney had made this move first you could see it as a risk akin to Nintendo's gamble on the Wii's television remote control-style system, but the launch of Infinity is more like when Sony and Microsoft saw the Wii's potential and made their move into gesture controls with PS3 Move and Xbox Kinect technology.
To launch Skylanders, Activision overcame technological complexities in creating its interactive figurines, a comparatively high retail price and the vagaries of launching a new video-game franchise surprisingly easily. Parents can attest to the attraction of Skylanders' collectable toy figures and video games. The franchise recently passed the $500m (£317m) retail milestone.
The arrival of Disney Infinity, developed by Avalanche Software, shouldn't be half as difficult. Nor is it a surprise. Perhaps it's more of a surprise that it's taken this long for Activision to have a competitor in this new market.
On first sight, the Disney game looks almost identical to Skylanders, not least in its use of plastic toy figures to access in-game characters and save progress via a USB-powered base unit. On closer inspection there are substantial differences.
For a start, the Disney toy characters extend the appeal beyond those who play video games. This contrasts with Skylanders' original characters, and leans heavily on the consumers' appetite for further adventures from Disney's regulars.
Disney Infinity also offers a more varied video-game experience with tailored interactions for each of the franchise-specific playsets (purchased separately). There is also a Toy Box mode that enables players to create their own games from scratch. All this can be played alone, or with up to four friends via the multiplayer mode.
The game comes in a starter pack that offers three film adventures (Monsters University, The Incredibles and Pirates of the Caribbean), three figures, the game disc and the USB peripheral. This can be expanded with the purchases of new adventures from different Disney franchises and figure packs.
Disney Infinity takes its retail aspect further with a plastic token upgrade system. Rather than players earning character upgrades, they have to purchase the tokens in foil packs. With a growing number of discs likely to be made available this is perfect not only for playground swapping, but also for improving Disney Interactive's bottom line.
Despite the potential hard sell the game has been well received critically. The industry analyst Michael Pachter told the LA Times that "Infinity seems to be a perfect vehicle not only to leverage their brands in a game setting but to exploit toys and other licensing opportunities."
Make no mistake though, this is a big risk for the Disney Interactive Media Group. Formed in 2008 by merging Disney Interactive Studios and the Walt Disney Internet Group it has had 15 consecutive quarters of losses – some $977m in total. Disney Infinity needs to play a big part in turning round these fortunes.
Perhaps Disney Infinity's biggest weakness is, as Pachter highlights, how well crafted it is to fit business rather than creative ambitions. It not only makes a grab for Activision's video-game-meets-toy sales but also offers a more cost-effective route for delivering future film tie-in games.
Widen the lens to include Disney's recent acquisitions and Disney Infinity feels more business-led than ever. It matches Disney's morphing from a story-creator company to a story-gatekeeper and is perfectly placed to leverage characters to help recount the cost of its recent acquisitions: Lucasfilm (for $4.05bn in 2012), Marvel Entertainment (for $4.24bn in 2009) and Pixar (for $7.4bn in 2006). Expect Star Wars and Spider-Man playsets before too long.
Achieving this marks a creative departure for Disney, in that it usually keeps its imaginative worlds separate. Jack Sparrow and Mickey Mouse previously only interacted as mascots at Disney World. Disney Infinity requires a compromise so that its toys are visually related and collectable. The result is a pleasing set of chiselled cartoon characters but one that diminishes creative difference.
The figures have a tactile feel to them easily matching Skylanders. It's a testament to Disney's expertise in this area, as Simon Philips, general manager of Disney Consumer Products, underlines: "More than 200 million Cars die-cast vehicles have been sold worldwide."
John Vignocchi, executive producer for Disney Interactive described how Disney Infinity capitalises on this expertise. "Designers, project managers, retail marketers from the consumer products division were all brought in to help."
Other toy and video-game makers will watch Infinity's fortunes with interest. Others who could try to muscle in include Warner with its catalogue of film franchises such as Lord of The Rings, Hasbro with its Transformer action figures or Bandai with Ben-10.
More likely, however, it will be platform holders such as Sony, Nintendo and Microsoft that take this technology further. Nintendo has added the NFC chip to their Wii U controller and its Pokemon franchise seems a perfect fit for a physical toy version of its "collect 'em all" play-style.
John Coyne, vice-president of marketing for Skylanders, was quick to reinforce Activision's position after the launch of Disney Infinity. "We are flattered that one of the leading family entertainment companies is joining our toys-to-life category." The irony, not lost on Coyne it seems, is that Activision, rather than Disney, is the one leveraging fresh characters and stories here.
Still, such is the quality of Disney Infinity Activision will need to continue their innovation in gameplay, toys and characters to remain on top. The pressure is certainly on for their anticipated announcement of Skylanders 3 in early February.
The winner will not only be obvious from the balance sheet, but from playground activity. Parents be warned though, both games have the potential to dent the wallet for those who feel the need to collect all the figures. The Infinity characters are set to cost just under £12 each, on top of the £65/£55 game. So being selective is essential for getting good value. Get ready to say "no" in stores soon.
Andy Robertson is a family-gaming expert for the BBC and runs Family Gamer TV on YouTube