How Do Mobs Spawn in Minecraft Bedrock

Hello this is madhatter here and I am in a skyblock world to explain to you how mob spawning actually works in bedrock edition. My goal here is to give you the tools to design your own farm if you want to.

Designing farms is not for everyone, some people like to follow tutorials, but even if you are following tutorials these mechanics can help you identify a good farm from a bad one without even testing. This my not be 100% complete but the goal is to get you knowledge.

If you know something that is wrong, let me know it is not intentional and would increase my knowledge. But i want to make It clear Java and bedrock have completely different mechanics, and the mechanics you may have seen in a java players video may contradict these and that doesn’t

Mean they are bad at Minecraft. It means they are making assumptions based upon experience with a different game. Remember Java edition and bedrock edition are completely different games that share almost no common code, so it is dangerous to transfer assumptions from Java to bedrock without compete testing.

One last thing that we should talk about before we get started is if you are bored by the mechanics at least skip to the end and consider watching what things I avoid to prevent hurting the server, I should have markers in the description.

These are things that can harm the server and I personally do not think are worth the rates. Ticking Region First we should talk about ticking. In bedrock there are several settings for this. The most common setting is 4, If you would like me to do a section on 6, 8, 10, and 12

Let me know. Most people stick to sim 4 and sim 4 is the strange one that doesn’t match any of the other version, so I will be only talking about sim 4 in this video. What does SIM 4 mean. Lets start by looking at the sim 4 pattern.

To do this you can download the pack linked in the description and place and armor stand with a stick in its hand. This will bring up all of the ticking regions and a handy compass. The border just outside the number 4 is the edge.

Past that no redstone or mob AI task will run (unless some exploit is use to force load that chunk) the amor stand represents the players location and is not actually ticking the area, it is there to show you where your ticking area would end.

Generally things that happen each tick only impact things in this reason, things like “De spawning” are done based upon ticking mobs. For that reason the SIM 4 uses a different spawning algorithm than any other sim distance. SIM 4 spawns mobs only out to 44 blocks around the player, randomly despawns mobs after 32

Blocks and will not spawn mobs closer than 24 blocks from the player. If you want to see what this looks like simply give the amor stand a plank and we can see the spawning sphere. Now the reason for R44 is to prevent a monster from spawning then ending up immediately in unloaded chunks.

So from the pack you can see a colored circle at starting at 24 blocks ending at 44 blocks with an opaque line at 32 blocks. This is to show you the areas you can expect monsters to spawn, randomly despawn, and instantly despawn at while you are playing.

How do mobs spawn In bedrock, each tick a chunk is chosen, That chunk will attempt to spawn a mob, It first checks global mob cap, then checks density caps, then chooses a block. The game then starts at the top of the world going down to trying to spawn the mob.

It checks block types, light levels, then tries to put the mob on the north west corner of the block and checks for collisions. If all of these checks pass it places a mob there and attempts to “pack spawn” if the mob definition in the behavior pack allows for it.

Yes even in vanilla Minecraft there is a default behavior pack. You can get it from Mojang or you can find a copy on bedrock.dev. Those people are an awesome resource for making any sort of packs for Minecraft bedrock. As I was saying the algorithm starts at the top and goes to the bottom.

Does that mean that the spawning is faster up high… no bedrock doesn’t have a Y based spawning probability, the probability is uniform in the X and Z with mobs being placed first at the top and last at the bottom.

So build your farm where you like, it is just far easier up high and it really doesn’t impact the rates, just the spawn proofing effort. Unlike Java, bedrock has several different types of mob caps. In my opinion this is why passive mob spawning works on bedrock worlds but doesn’t work on java worlds.

So to start with we have global cap. Global cap in bedrock is 200. I would love to see the developers allow us to adjust this, like sim distance or render distance based upon our server performance, however we are hard capped at 200 regardless of how awesome your server or computer is.

Not all entities count toward global cap. Notably Villagers do not count to the 200 global cap, however named mobs, bread mobs, persistent mobs all do count to global cap. Next we have density checks. Density checks are there to ensure that not all 200 monsters are hostile cave mobs spawning

At the bottom of the world preventing other spawns. This keeps the total number of mobs per player low and is intended to evenly distribute mobs around the ticking area. Each mob has their own density checks, as well as each type of mob spawn having a density check.

We will start with what is a density. Unlike the diamond pattern we see with ticking area, density checks are in a rectangle counting all mobs in the chunks starting where the monster spawns going out 4 chunks from the monster (excluding the chunk the monster is in).

Don’t worry we have a way to visualize that too. We an armor stand where we think a monster will spawn, then put a chest in that armor stands hand. The chest will display the area that the mob counts right at it wants to spawn to determine

How many of each type of monster are in its density. Each monster has its own “desnity” cap plus the “spawn type” density. I won’t be covering the per monster densities as they change from time to time. But the spawn times are generally hostile surface, hostile cave, passive surface passive

Cave, ambient surface, ambient cave. As of 1.18 the hostile cave cap has been increased from 8 to 16, the hostile surface cap is 8, and the passive surface cap is 4 as well as the passive cave cap.

That means when the game is spawning a monster it count to see if there is already monsters in the red region that can be counted in the density. So now this is where a lot of people get confused…

You have to spawn proof around where the monsters will spawn… not necessarily around the player. Often times the player area will cover the monster density, but you can, I repeat can have monsters that you loaded outside your ticking area that count to mob cap and prevent spawning.

You have to spawnproof the density, not just the ticking area. We talked about surface cap, cave cap, passive caps and hostile caps before, but we didn’t talk about what makes a mob a cave mob vs a surface mob.

To start with we will talk about a monster that spawns with nothing but air or leaves to the top of the world. These are going to be surface cap. Generally this is the easiest cap to understand, montsers that spawn with access to the sky are surface cap.

In addition monsters that spawn out of a spawner, regardless of if they have blocks above their head or not are surface spawns. That is right, the cave spider spawner you found at the bottom of the world makes surface cap cave spiders… It may be confusing, but spawners always spawn surface cap monsters.

Structure spawns are always cave spawns regardless of the type of blocks over the head. If you don’t know what a structure spawn is, we will get to that later, Mobs that didn’t come from spawners but spawned with a block over their head are cave spawns. And finally, the converted mobs.

These are cave mobs. For instance, a slime that is broken into little slimes, the big slime may have been a surface slime, but the little ones, those are cave slimes. This is why open-air slime farms are so much better than cave slime farms.

Because the surface slimes when hurt turn into cave slimes and immediately open up a spot for another surface slime to spawn. Converted drown spawns are also cave as well as converted villagers. For passive mobs, any passive mobs that you bread will be cave passive mobs, where any

Natural spawning passives on the surface are surface mobs. So if you are looking to allow cows sheep and chickens to spawn in your area, bread them, then kill the wild original ones and grow up the babies. Structure spawns are monsters that spawn a specific building in the world.

They are strange compared to other monsters. Some examples of structure spawns include wither skeletons, guardians, blaze (that don’t come from spawners), witches that spawn in the witch hut, pillagers that spawn in a pillager outpost, and I think that is it at the time of writing.

In bedrock they spawn on a specific spot in the structure. For guardian spawn spots see my other video on the topic using the same pack. For the other structure spawns that are predictable, see the wiki on the pack or I may put out videos on those in time.

For the nether fortress I need to have a think about how to support those in this pack. I have not come up with a good solution yet. But I will tell you that Dr. Jan Cyan has a really good video explaining fortress farms.

I don’t know them, however that is where I learned so I will point you there. These spawning spots are generally 1 spot per structure per chunk. The spawning method is different and can be a bit confusing. This is where I am a bit shaky on my knowledge but I will do my best.

The first thing that is weird is that the structure spawns occur after the natural spawns and get 1 additional cap space in the cave cap. But for a spawn of that monster to occur in the spawn spot a similar spawn attempt must have been attempted and failed.

Again this is based upon inference from how I see it working, but it makes sense to me. So for instance, for a witch to spawn, a surface hostile mob spawn must have occurred but failed in that tick for a witch or pack of witches to spawn.

This is why you need to have a chunk that is dry for a witch farm to function. In the case of a fortress farm you need any hostile mob spawn to occur or fail for that chunk to spawn a structure spawn. In the case of guardians, things are very strange.

It seems that you must have a surface, aquatic mob attempt to occur for a pack spawn at the highest water block in the spawn spot in the spawn column. And for pillagers it seems you need a hostile surface mob attempt to occur.

An attempt that fails due to light will still allow the structure spawn to occur. Again I apologize if this is confusing, there seems to be a lot of ifs and buts in the structure spawning algorithm that are hard to get your head around.

But important take aways, you need to have spawn attempts, you need to have specific types of spawn attempts for each type of structure spawn (wet for guardians, dry for most others) and those occur on 1 block per chunk. Slime can randomly spawn on the surface ins swamps or in slime chunks below Y=40.

All bedrock seeds use the same seed for the slime chunk generation so they are not randomly distributed like on java, In this pack you can see slime chunks if you put a nautilus shell in your off hand.

So now that we have covered how spawning works we should cover some of the safeguards on the world and how some people have exploited those safe gaurds in ways that can harm your world. I am not saying that these should be banned or should never be used, but I am saying there

Are ways around them that work very well and don’t circumvent safeguards inside of Minecraft The first and most scary one is dual dimension farms. Dual dimension farms use sending mobs to the nether to get them out of cap instantly.

In java this is not as scary because java force loads the nether for a few seconds and allows the mobs to be killed. In bedrock it just writes the mob to the save file in this location. This can cause mobs to rapidly build up and potentially break your server when you enter

The nether. These types of farms can and do break servers and cause roll backs. I would avoid them completely. They cannot be AFKed reliably and if you choose to AFKthem and 1 player disconnects the server rolls back It simply is not worth the risk.

The portal gold farms to not respect global mob cap and do not turn off to protect the server. Even with only one dimension you can end up overloading a server. I would not recommend using these in your world simply because there are a few zombie

Piglin based nether only gold farms that will get you more than a stack of blocks per hour of AFK. They are not too bad to build and are fast enough. If Mojang checked global cap I wouldn’t complain about these farms much, but I don’t like that they do not check cap.

Spawner based farms also do not check global mob cap. They can over run a server if you don’t have killing mechanisms on them. I would recommend using them until you can get a general mob farm up and running. But long term I would avoid this type of farm.

I know a lot of people will be unhappy with that comment, but really do remember, if you trident killer stops working, and you are AFK… you can lag the server out and cause a roll back for you server mates. Early game they are awesome.

But I would move away from them as your world progresses Well that is what I have for you today, I hope you enjoyed. If you did leave a like, if you want more please subscribe. If you want early information or to help out join the discord. Anyway this has been hatter BYE