Minecraft has infinite seeds since they are just randomly generated numbers. As numbers do not ever end, there are theoretically infinite worlds out there. Sometimes, those seeds coincide with numbers from the real world. Lucky number 13 is a seed. The number 69 is also a seed. Likewise, 420 is a seed, and so on and so forth.
Is there a seed for 666, which is considered a cursed number? There are many theories about it and what it does to the game. Here's what we know so far.
Minecraft seed 666 explored
There are many theories surrounding the 666 seed. In the Christian faith, the set of numbers is meant to be associated with the devil, while in the Book of Revelations, it is tied to the end of the world, the devil, and destruction, which is why the number set has such a negative connotation.
One player posted this to the Minecraft Wiki, detailing their frightening experience:
"In Minecraft, it is said that the seed 666 is cursed and inclined with the devil himself. Yesterday I got in the game with always day and creative cause I was a bit scared? I heard that the players who play in the world afterwards become more paranoid and have phobias they never had before."
"It is also said that there is a dimension in which mobs are twice everything, speed, violence and stuff. Things are also said to be more REAL. Sightings of several crosses and creatures are reported."
However, it's important to note that these are just folk tales. There are no Minecraft seeds in which unique mobs spawn, or with pre-existing structures like crosses.
Finally, there aren't any in-game worlds in which an NPC exists other than in the Education Edition. The 666 seed may have some world generation Easter eggs to mess with the community, but that's about the extent of what's possible.
It is possible that the vibe surrounding this particular seed makes people uncomfortable. If you've heard that a seed is haunted or features scary beings, it can leave you with a sense of fear.
Fortunately, there's nothing haunting about the 666 seed. Even if there was something scary associated with it, note that it is only a video game. As haunted as a seed may be in Minecraft, it cannot influence the real world.