Spin-offs are typically thought to be little side games that you’re able to enjoy while you wait for a new entry in the main series. For example, something like Halo ODST fits that description quite well. Yet, not every spin-off is like that one. Some spin-offs are so successful that they result in an entire sub-series.

If they get popular enough and are around long enough, people even forget or never realize that they were spin-offs in the first place. This has happened a bunch of times. Of course, everyone knows series like Mario Kart are spin-offs because Mario is in the name and all over the branding. Yet, there are some that are different enough from their parent series that it’s easy to forget that they’re spin-offs. Here are some examples.

Futaba Sakura furiously typing with a concentrated expression on her computer in Persona 5.

8Persona Series

The Megami Tensai Series Spin-Off

Atlas loves its spin-offs and has made several from the Megami Tensai series, including the very popular Persona series. These games are unique RPGs that typically feature a group of teenagers and some supernatural elements.

The spin-off series seems to have been inspired by Shin Megami Tensei If…, a game that also features teenagers and a high school setting. The latest Persona games are much more famous than that title, though, mainly due to the incredible critical response some entries have received.

zhuge liang at sunset in dynasty warriors: origins, with liu bei, guan yu, and zhang fei in the background.

7Dynasty Warriors Series

Romance Of The Three Kingdoms Series Spin-Off

There have been manygreat Dynasty Warriors gamessince the late ’90s. As a result, people forget or may not know that it started as a spin-off of the Romance of the Three Kingdoms series.

The first Dynasty Warriors was a fighting game, but most of the entries since have been hack-and-slash titles. Both genres are in stark contrast to the Romance of the Three Kingdom games, which fall into the strategy and simulation genres.

Rune Factory Guardians Of Azuma hina waving from her ship.

6Rune Factory Series

Story Of Seasons Series Spin-Off

The original Rune Factory game was a spin-off of Story of Seasons (aka, Harvest Moon). Unlike many spin-offs, the Rune Factory series isn’t a huge departure from its parent series. After all, it still puts a heavy focus on farming and social simulation.

However, the Rune Factory games also have action RPG and dungeon-crawling elements. So, there is a bit of combat in these games, while Story of Seasons stays away from that sort of thing. Both series have managed to remain popular, and Story of Seasons only seems a little more well-known.

A screenshot showing cover art for Shin Megami Tensei: Devil Summoner with a suited character holding a gun.

5Devil Summoner (Soul Hackers) Series

Megami Tensei Series Spin-Off

In the mid-1990s, the world was treated to another spin-off of the Megami Tensei series: Devil Summoners. This RPG about a protagonist investigating demons spawned a series that would be renamed Soul Hackers.

The games typically revolve around demons and investigations. Although they’re set in a different world from the main Megami Tensei games, there are some similarities between the two series when it comes to gameplay. For example, most entries in the Soul Hackers series also use a turn-based battle system, like the Megami Tensei titles.

A dragon egg with headphones on it in front of Bella Goth in The Sims 1.

4The Sims Series

SimCity Series Spin-Off

The connection between The Sims and SimCity is pretty clear from the name alone. Yet, because of The Sims' huge popularity and fame, many believe it came first. That is not the case, though.

The first SimCity was released in 1989, and it had several spin-offs before The Sims came out in 2000. So, the developer, Maxis, went from allowing you to manage cities to having you manage families. The latter caught on a lot more as The Sims became much more famous than SimCity.

A woman with an eyepatch stands in a garden area in NieR Automata.

3Nier Series

Drakengard Series Spin-Off

Nier is a series of excellent action RPG games that began in 2010. There have been a few releases and some remakes. Arguably, the most popular game of the bunch is Nier: Automata, which was very successful.

This whole series started as a spin-off of the Drakengard games. To be more specific, the first Nier was a follow-up to Ending Five of the original Drakengard. It has been a while since a mainline Drakengard entry has been released, so Nier feels like the bigger series now.

Sports Car speeding in Forza Horizon 4.

2Forza Horizon Series

Forza Motorsport Series Spin-Off

Forza Horizon has become a very popular racing series, and several entries are amongthe best racing games you can play on Xbox. However, before there was a Forza Horizon, there was Forza Motorsport.

Motorsport is more of a simulation driving series, while Horizon is a bit more arcade-like. Some people forget that Motorsport came first. In fact, there were four Motorsport games before Horizon came onto the scene. This is likely forgotten because Forza has become a more significant name in gaming since the Horizon series began.

Mario and a Goomba in World 1-1 of Super Mario Bros (1985) for the NES.

1Super Mario Bros.

Donkey Kong Series Spin-Off

At this point, Super Mario Bros. is arguably the most famous gaming series ever and hasspawned many of its own spin-offs. Yet, it began with 1983’s Mario Bros., which was a spin-off of Donkey Kong.

Many don’t know this fact because it was so long ago, and Mario has become so much more popular than Donkey Kong. That said, DK is a well-known series in its own right. The connection between the two series comes from Mario himself. In the first Donkey Kong title, he was simply called Jumpman and was the protagonist. Once the Mario series started to be established, though, DK transformed from his series' antagonist to the protagonist.