A lot of brainpower has been spent speculating about how Nintendo's Legend of Zelda series fits into a cohesive timeline. To try and appease these fans, the developer put out an official Zelda timeline in the Hyrule Historia collector's book that first released in Japan in 2011. The exercise is interesting due to the breadcrumbs left by repeated motifs and themes in a franchise focused on adventure and mythology. However, few games have as much real connective tissue to its predecessors as The Legend of Zelda: Breath of the Wild 2, a sequel to the Switch's hit 2017 launch title.
While there have been a few games with continuity, Breath of the Wild has the chance to spawn something even more significant. Not long ago, Nintendo announced Hyrule Warriors: Age of Calamity, a prequel to Breath of the Wild developed by Koei Tecmo in the style of its hack-and-slash Dynasty Warriors series. Though this announcement came alongside series producer Eiji Aonuma confirming a longer development on Breath of the Wild 2, the reason why this delay is occurring opens more possibilities.
Aonuma said the development team needs more time to make the land of Hyrule seen in Breath of the Wild "even more impressive" for its sequel, and having Age of Calamity coming out in the meantime suggests these improvements can go after something completely new. The hack-and-slash game will tell the story of the war that sets the stage for Breath of the Wild, and Age of Calamity will hopefully flesh out its characters in the process. Because of that, Breath of the Wild 2 can focus on telling more unique stories without having to bog itself down with previous baggage. In that way, it may be able to do more than typical sequels by helping establish a true "subfranchise."
Games With Direct Continuity
Prior to Breath of the Wild, the quintessential example of a Zelda game with direct continuity was Ocarina of Time and its follow-up Majora's Mask on the Nintendo 64. Majora's Mask begins after Link saves Hyrule from Ganondorf, returns the Master Sword to become a child again, and then sets off on a journey to reunite with his departed companion Navi. He falls into the land of Termina, a twisted version of Hyrule, and has to save its denizens from a certain demise.
Though this is a continuation of the first game, how Majora's Mask ties into its predecessor is questionable. It has become a popular fan theory that the events of Majora's Mask are Link trying to resolve his grief after dying based on the game's heavily death-focused themes and returning, but different characters (though in real life this was a product of reusing Ocarina of Time's engine to quickly turn out a sequel). Technically, these games also connect to Twilight Princess, in that the Hero's Shade who teaches Link is Nintendo 64's Link according to the Hyrule Historia.
Yet this inclusion feels more like an Easter egg, as none of the games truly connect through anything more than the appearance of one Link. Their worlds and the characters within are unique. Another set of games that comes closer to this are The Legend of Zelda: The Wind Waker on GameCube and its DS sequels. This flooded Hyrule saga is the only one until Breath of the Wild that has three directly contiguous entries. However, only Phantom Hourglass is a direct sequel to Wind Waker with the same Link and Zelda; Spirit Tracks takes place 100 years in the future when nothing is recognizable.
A few other games have more tenuous connections. A Link Between Worlds is a kind of sequel for A Link to the Past, but it also feels like a reimagining. Oracle of Ages and Oracle of Seasons are linked in that playing one changes events in the next, but they could go in any order. The CD-i Legend of Zelda games also have some crossover, but those are hardly worth considering.
How a Breath of the Wild Subfranchise can be Different
The aforementioned direct sequels often feel disconnected, or they attempt to carry on ideas from previous titles while creating a new world for Link to explore. For example, Phantom Hourglass takes place in a different stretch of ocean complete with its own problems and cast of characters divorced from Wind Waker.
A subfranchise within a larger series should ideally focus on telling new, unique stories related to one facet of a previously-established canon, often with its own mainline and spin-off games. The Sonic Boom subfranchise, as derided as it may be, has some continuity and multiple spin-offs within its unique take on the Sonic universe, both in video games and television, making it a good example of the kind of model Breath of the Wild could be utilizing.
By having multiple games sharing a direct continuity in a bubble, the Breath of the Wild subfranchise has the ability to flesh out ideas without encumbering new main entries. In regards to its own lore, Age of Calamity may offer more characterization for the Champions that many argue are underutilized in Breath of the Wild, leaving the sequel open to dive deeper into its own plot and evolve the world. Sequestering these games as something unique that could continue into perpetuity also leaves open the possibility of new takes on Zelda separate from that subfranchise being created.
The closest entry in the series to achieving this kind of cohesion and world building with spin-off titles was Twilight Princess — though it's hard to say games like Link's Crossbow Training or a Picross title only available through My Nintendo rewards hold the same narrative potential as Age of Calamity. Creating new games with familiar themes is great for experimenting with ideas and mechanics, but Nintendo taking some time to smell the roses by fleshing out Breath of the Wild's world is a welcome change with the potential to make something truly special.
The Legend of Zelda: Breath of the Wild 2 is in development.