Videogames are a lot like medieval kings: they rely on loyalty, command a ton of money, and invariably have a ton of illegitimate kids. Some of these children are readily adopted into the family, whereas others are relegated to toil as spinoffs away from the main court. And occasionally, they're banished far away in the hopes that nobody will ever know their true parentage.RELATED: The Best Video Games Of All Time, According To MetacriticBut where gamers are concerned, no secret successor is safe. Some of gaming's best titles have sequels hidden deep within their lore or written onto their very DNA. Whether they're disowned by their parent companies or morphed into another franchise entirely, there's no denying where they came from. So follow us, as we jump into the world of videogame genealogy and see who some of our favorite properties write Father's Day cards to.

6 Kings Field, Dark Souls

Skeletons attacking in hordes

When people ask if you've played the original Dark Souls, they usually mean FromSoft's seminal Demon's Souls series. That is unless they've got a dead, glazed look in their eye - then they're probably talking about King's Field. This dungeon-crawling hack n' slash adventure practically bleeds Dark Souls from its brooding setting to the difficulty of its gameplay, but the connections don't end there.

Familiar names such as Seath the Scaleless, Nashandra, and Sen's Fortress are lifted directly from King's Field 4. Even the Soulsborne franchise's most famous weapon, the Moonlight Greatsword, originally appeared in the early 2000's series. This is no surprise given FromSoft's delightfully vague approach to world-building, and it's entirely possible that the land of Verdite is just another doomed kingdom like Lothric and Drangleic.

5 Snatcher, Metal Gear Solid

Metal Gear Solid and Snatcher Cutscene Screenshots

You've almost certainly heard of Metal Gear Solid. But have you ever heard of Snatcher? Another Kojima production, Snatcher puts the player in a grim future where disease has wiped out billions and dangerous robots roam. It even sounds like a Metal Gear plotline, and it turns out Snatchers aren't the only robots to worry about.

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Simply put, Snatcher is crazy about Metal Gears. They're peppered everywhere. Your robotic partner is even called "Metal Gear Mk 2", and the game's lore references the "Metal Gear Menace" which appeared around the 20th Century in an obvious nod to the events of Metal Gear Solid 2. It may lack snakes and CQC, but this direct line of continuity marks Snatcher as a Metal Gear Solid sequel in terms of story and a prequel in terms of the actual release date. Get your head around that one.

4 Drakenguard, Nier

Nier and Drakenguard characters attacking

Quick, name the apocalypse that kicks off the Nier series. Did you say "fantasy dragons bursting in from another dimension"? Because that's pretty much what happens. In Ending E of the fantasy game Drakengard, hero Caim and his dragon end up being teleported to Tokyo in 2003, where they are immediately killed by military response. Their death seeds magic into the world as a terrible disease.

This magical plague causes the all-out apocalyptic setting for the original Nier, as well as setting up the story thousands of years later in Nier: Automata. Certain NPCs and references to Drakengard are also hidden amongst Nier's lore. Though they might be completely different beasts, it turns out these two games are birds of a feather. Or, dragons of the same wing.

3 Prince of Persia, Assassin's Creed

Prince of Persia and Ezio Doing Parkour

Given their shared love of people-stabbing and wall-running, it's not hard to imagine Altaïr took some inspiration from The Prince. In fact, the Assassin's Creed series began as a spinoff to Prince of Persia: Warrior Within. Originally called Prince of Persia: Assassins, the game involved playing as a guard who must protect a computer-controlled version of The Prince from harm.

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Of course, the title took on its own life during development and became the series we know today. But even though Assassin's Creed has bloomed into its own hit franchise, it's not hard to see the similarities. Former Assassin's Creed director Patrice Desilets has even been quoted as saying that in the end, he believes that both Altaïr and The Prince share the same title of "Prince of Persia", despite very different backgrounds and stories.

2 Half Life, Portal

Chell holding a portal gun, Gordon holding a gravity gun

Players of the Portal games will be well aware of the bitter rivalry between Aperture Science and Black Mesa. But what many players don't know is that the Half Life timeline goes hand in hand with Portal's, and that Half Life's ending is directly connected to Chell's misfortunes. As it turns out, Aperture fell quiet because of more than just deadly neurotoxin.

When Chell is awakened by GLaDOS, the AI makes it very clear that nobody's coming to help. That's because the game takes place just after The Combine appear to conquer Earth, with GLaDOS indirectly referencing this apocalyptic invasion several times when talking about the unknown conditions on the surface. Eagle-eyed players can also find the dry-dock for the Borealis, a lost Black Mesa research vessel, in Portal 2.

1 Wolfenstein, Commander Keen, Doom

Blazkowicz and Doomguy firing, Commander Keen running

There's plenty of famous families in gaming, including that of BJ Blazkowicz, the protagonist of the Wolfenstein games. When he's not turning Nazis into ex-Nazis by way of gunfire, he's the patriarch of an Id Software superfamily that connects three of their most famous titles. See, BJ ends up having grandchildren, one of whom becomes a spacefaring child adventurer called Commander Keen. Later on, Keen has his own grandchild, who grows up to be the Doomslayer himself.

Id Software has confirmed in interviews that this lineage is canonical and that all these games take place in the same universe, and you can even find Commander Keen's skull in Doom 2016. They're more spiritual sequels than anything else, but that's a technicality we're willing to accept if it means connecting a plucky eight-year-old astronaut to a crazed demon-stabbing maniac.

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