An all mob farm is one of the basic types of Minecraft farms. The all mob farm's purpose is to farm all mob's drops usually gunpowder and bones for tnt and bonemeal. This is an exteremely easy way to get multiple drops that you want out of one farm.
A basic all mob farm has a few key components that make it function properly. The first one is a spawning area. You can either use multiple platforms or one bigger patform but the design you use for the spawning area depends heavily on. The kill method. The kill method is the most important part of any farm because if you can't kill the mobs that are spawning then it won't produce any items.
There are many different kill methods but the three main are using campfires or lava to burn the mobs. The second is using fall damage and having them land on hoppers. And the third and best if your farm has a way to include it is by killing them in a box with a sword. This is best because you can use looting and you also get xp.
After you have decided on your farms kill type(for our example we will be using a fall kill) you also have to choose your spawning platforms. In my opinion the simplest spawning platform is a flat platform floating in the air with a dispenser that dispenses water onto it. I would make on of these by placing down a bucket of water on a floating block then build out until the water goes just to the edge but doesn't flow over. Then you set up a redstone clock with repeaters and redstone dust to turn the dispenser on and off for periods of time. This can be optimized by making two clocks that place the water for only a short time before they remove it instead of it being 50 50 water and no water.
The last step in your farms is making shure mobs can spawn at all and optimizing it to be faster. All the blocks in your farm have to have a light level of 0 if you want mobs to spawn on them. You can check this in the f3 menu and look at block light level or download a mod called minihud that you can use to put a light level overlay on all the blocks. You have to remeber that if your farm is outside and it is nighttime the light level will obviously be 0 everywhere if you don't have a light source. You will have to come back and test it again during the day. If your light level is higher than 0 you should put a roof over your farm to make it work. And for optimizing your farm try to build it over an ocean so no other mobs can spawn outside it and afk at least 80 blocks above the bottom killing area. We will talk about further optimizations later on but for now I think this is sufficient.
All mob farms are usually one of the first farms you want to build in your world.
The lower in the world you make your mob farm the more efficient it will be.
Once you build your farm you can modify it to use a looting weapon to kill to make it more efficient.
This is a link to Gnenbom's all mob farm. It is a basic all mob farm that uses the concepts I have discussed.
Three all mob farmsThree different mob farms that poduce different ammounts depending on your needs.
Extremely inefficient all mob farmDon't build this.
The amount of mobs that can be in a single dimension in a single player world in minecraft.
Mob CapMobs spawn in packs instead of individually. In this section I will explain how you can take advantage of that.
Pack SpawningWhy mob farms are affected by the highest block in the world at specific cordinates.
Height Map