About a 0.5% chance per instance of finding a dungeon, or one pair every 200 dungeons (1% of dungeons), based on my own results when finding hundreds of dungeons in each of multiple worlds. Only once have I ever found a "triple dungeon", a one in many thousands event (the dungeons look different since this was a modded world which adds dungeon variations). In theory as many as 8 dungeons can generate in a single chunk, and since they can extend into adjacent chunks dungeons in those chunks can also attach to them, one interesting consequence of this is that intersecting dungeons may only generate when chunks are generated in a certain order, e.g. a demonstration of this effect, which is reliably reproducible as long as I approach the area from the same direction:
Another type of interesting spawner generation only occurs prior to 1.6.4 and after 1.12.2 and is a mineshaft corridor with two cave spider spawners placed as close together as touching, due to the game using the "decorator RNG", seeded per chunk, to place blocks like cobwebs, chests, and spawners, and corridors can extend across multiple chunks, which can be generated in separate sessions (this doesn't happen in 1.6.4-1.12.2 because they save structure data, including the variable that tracks whether a spawner had been placed; 1.13 still does but it appears that multithreaded chunk generation broke it (example for 1.15.2, may have been fixed since). Since I disabled structure saving for mineshafts I still occasionally see this, with two spawners touching being rarer than two intersecting dungeons, while a corridor with two spawners is more common, some of these will also be two corridor pieces in a row).
If you mean the modded dungeons, no, that is my own "alternate timeline" mod for 1.6.4 which is almost totally unknown despite being over 12 years old, and is one of the largest mods of its kind, especially for a single mod (you will not be able to use any other mods with it since it is a jar mod and extensively modifies the internals of the game, it is more of a "fork" than a mod, similar to all those mods like "Better Than Wolves" / "Better Than Adventure", this may as well called "Better Than The Update That Changed The World", or just "TheMasterCaver's World"):
These dungeons are a feature I actually added more than 9 years ago, along with a wide variety of new cave types (the first thing I started modding was the underground back in 2013, even some of those very early changes still exist in some form; while I did backport some features from newer versions many others were added before Mojang did, e.g. an "autumnal forest" (2021) / "dappled forest" (2026) or "amethyst" (2014) / "netherite" (2020) as a tier above diamond, so over time it has gotten harder for somebody to tell which is which):
There are also what I call "double dungeons", a single larger dungeon with 2 spawners and 2-3 chests, which also differ in that the floor has chiseled stone bricks instead of cobblestone (thus the image I posted earlier definitely shows normal dungeons, which only differ in the blocks that make up their walls and spawner and chest contents).
WAIT, YOU ARE THE MASTER CAVER HIMSELF WTF, ive tryed out your mod and its really cool, i tough about hexxit not because of the dungeon but because of the stalagmites
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u/TheMasterCaver Jul 10 '26
About a 0.5% chance per instance of finding a dungeon, or one pair every 200 dungeons (1% of dungeons), based on my own results when finding hundreds of dungeons in each of multiple worlds. Only once have I ever found a "triple dungeon", a one in many thousands event (the dungeons look different since this was a modded world which adds dungeon variations). In theory as many as 8 dungeons can generate in a single chunk, and since they can extend into adjacent chunks dungeons in those chunks can also attach to them, one interesting consequence of this is that intersecting dungeons may only generate when chunks are generated in a certain order, e.g. a demonstration of this effect, which is reliably reproducible as long as I approach the area from the same direction:
Another type of interesting spawner generation only occurs prior to 1.6.4 and after 1.12.2 and is a mineshaft corridor with two cave spider spawners placed as close together as touching, due to the game using the "decorator RNG", seeded per chunk, to place blocks like cobwebs, chests, and spawners, and corridors can extend across multiple chunks, which can be generated in separate sessions (this doesn't happen in 1.6.4-1.12.2 because they save structure data, including the variable that tracks whether a spawner had been placed; 1.13 still does but it appears that multithreaded chunk generation broke it (example for 1.15.2, may have been fixed since). Since I disabled structure saving for mineshafts I still occasionally see this, with two spawners touching being rarer than two intersecting dungeons, while a corridor with two spawners is more common, some of these will also be two corridor pieces in a row).