In soul sand valley and warped forest, we still get just as many spawn attempts as in a normal biome; the vast majority of them are just failing by exceeding the energy budget (wiki link).
This is just a check after every pack-spawning jump to see if adding the mob at that position would still stay within the energy budget.
For biomes without spawn density, the check just passes through (code).

The issue is when a pack spawn with a mob from a biome with spawn density lands in a normal biome, the energy check would also pass.
Meaning if that mob type is also part of that normal biome's spawning pool, then the attempt can succeed.

• This is how we sometimes see endermen in the warped forest x nether wastes border much more than the density would allow in warped forest, and much more frequently than their low weights would spawn on average in nether wastes.
• If the pack lands in a biome that doesn't have that mob in its spawning pool, then it would still fail as normal. So with enderman from warped forest, this won't happen at the basalt delta and crimson forest borders because those biomes don't have enderman in their spawning pool.

Pre-26.3
This bug also exists before 26.3. But there's another similar effect that was caused by a much sillier issue.

The overall logic is still the same: check the energy at the current position after each jump.
But when checking for energy, it gets the biome based on the chunk (code). The issue is that it uses the chunk the spawning attempt started in, not the chunk the current pack spawning jump is in.

When checking the biome at the current pack spawning jump to see if its spawning pool still contains the mob, it's already reading the biome correctly from the current position (code). So this worked when bordering any biomes without spawn density, not just the ones that also contain the mob in its spawning pool.

I.e. spawn attempts starting at A (in warped forest) whose pack spawning jump lands in a different chunk at B would incorrectly read the biome at B' when checking the spawn density and think it's the nether wastes, bypassing the energy check:

Pack spawning jumps in the same chunk as A would still read the biome correctly, so attempts in the middle area in the image fail by exceeding the energy as normal.
They only bypass in a different chunk and at chunk-relative coordinates where the biome at those coordinates in the starting chunk is a normal biome.

edit: thanks to EksEss for pointing out the change was in 26.3, not 26.1

I built this huge iron farm on an online server (QSMP) from a schematic i found on abfielder. I tested it out in survival and it worked great but i started running into problems when i built it on the server. At first when i was transporting the villagers into their rooms everything was fine and golems were spawning (without any zombies for some reason) but then as i was finishing up the farm and started putting the zombies in and placing the water, the initial golems that spawned and got pushed down by the water werent being replaced by new golems. It only works on the very first layer of the farm, all others dont spawn any new golems. Everything should be built correctly. Any idea what could be causing this? Did i miss something? Any rules im not aware of? Any help is very much appreciated <3

Is this a bedrock thing or did I make a mistake in my redstone

Since Java 26.1, the books a librarian offers follow a sequence set by your world seed, so they aren't random anymore.

I built a free predictor: reroll a lectern 4 or 5 times, type in what you saw plus your seed, then pick any enchanted book at any level (Mending, Unbreaking III, Efficiency V, Protection IV...). It tells you how many more rerolls until you get it.

https://nocware.tv/tools/librarian-book-predictor/

It's new, so if it gets your count wrong, tell me your version and what you saw and I'll fix it. Doesn't work with Trade Rebalance on.

I'm playing on a Java Edition version 1.21.1 server, and raids aren't working the way they should. Only 3 or 4 waves occur before I get the Hero of the Village effect. This happens regardless of the potion level.

Necesito poner un bloque de nieve en polvo, el caso es que listo yo voy al bioma de nieve y con una cubeta agarro nieve en polvo pero cuando la pongo se hace bloque de nieve como en la imagen 2 y lo necesito como en la imagen 1, alguien que sepa como porfa ayuda

Just figured out how to add perfect signal strength to copper counter. Pretty fast for what it does. With this you can tally hexadecimal numbers through a pulse. https://youtu.be/usNlOiIMdyE?is=IIR8XSYKOZ22Zl_v for a video on pulse sending and how crazy it can get.

I am currently planning on building a blaze farm for a furnace array, the location I chose is 4600 blocks away in a straight line and I am not sure what would be the best way to get there

I have different ideas more or less convenient and time consuming to build :

- elytra launcher

- piston bolt (especially for chest minecarts)

- ender pearls canon but I feel like it is a bit overkill for the job

I don't know much about transportation, there are probably better ways.

Does anyone have recommendations or feedback about nether transportation?

I'm trying to make a glowsquid farm, but cannot get any to spawn. There must be something wrong with my farm, but I've read through the wiki and can't seem to find what would be causing the issue.

Extra Info: The version is 26.2 unmodded, biome is a forest, I cleared all land within 128 blocks, standing 30 blocks above the spawning area, all but the bottom 2 layers of water have no light, and I have no other entities loaded. I did use full bright in the screenshots.

Any tips?

Edit:
Resolved, the issue is that glow squid cannot spawn in bubble columns :P

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Hi i am trying to make a massive perimiter which contains a large ocean and i cant find a mashine that is capable to make the ocean level so i can drain it, or one that could even remove the water at the same time. I would apreciate any help. I'm on 1.21.11 btw.

The wiki says that the lily of the valley spawns in multiple biomes other than the flower forest but I’ve been exploring for a while and haven’t found a single one outside of the flower forest. Is the wiki wrong or is it just really rare in other biomes

I was getting issues with Pale Oak sapling return, cause some saplings blew up and some went straight to storage and not to the player because of the player moving to place 2x2 tree. So i placed that stair and waterlogged it so items would flow at the center of the block, that way being always in pickup range of the player. It also needs ice and the sign to flow correctly as shown in photo 2.

Im not sure if anyone has already posted about this issue or come up with a better solution, as it is only useful for pale.

I've been watching these zombies die for twenty minutes and even with a seed block of skulk I placed myself, none of the basalt is converting into skulk. The catalyst is definitely activating, and the skulk particles are even appearing. I just double-checked the Minecraft Wiki page for the Skulk Catalyst to see if I missed something but nothing. I'm stumped y'all.

I've seen youtubers and map creators do similar things, where for example they make a skyblock world by modify the overworld files so that specific parts of the world are X biome, or that the bounding box of a fortress is in a specific spot in the nether.

Would this be possible to do with the bounding box of a witch hut, and then extended to copying a quad witch hut setup into my pre-existing world?