Old



Old is a world type exclusive to the Bedrock Edition. The purpose of this world type is to provide smaller worlds on older or low-end devices that do not perform well with infinite worlds.

Creation
To create an Old world, simply select the "Old" type in the World Type dropdown of the world creation screen. Optionally, on low-end devices, toggle "Limited worlds" in the Video section of the options screen.

Overworld
Old worlds consist of a finite map with an area of 256×256 blocks with 128 maximum block height.

Biome which cannot generated in this world type:
 * dark forest and dark forest hills
 * mushroom fields and mushroom field shore
 * mountains and variants
 * snowy mountains

However, as a result of their limited size, only a few biomes can be generated per world, also biomes that generate in here are shrunken 4× (16× area) to allow more biomes to generate. When creating an Old world, the player will always spawn in the middle of the world. If starter map enabled, map is in scale level 2/4 rather than of 3/4.

Structures which can generate in the Overworld in this world type are:
 * Villages, Only 4 variants of villages will generate, which are plains villages, savanna villages, snowy tundra villages, and desert villages, taiga villages and snowy taiga village cannot generated.
 * Lakes can still can generate normally, but lava lakes will not generate near bedrock. Also, lakes will not generate under Y=55.
 * Other generated structures, such as mineshafts, ocean monuments, woodland mansions, strongholds, dungeons, desert pyramids, jungle pyramids, swamp huts igloos, underwater ruins, and shipwreck never generate, making resources very limited.


 * Unlocking last tier of Cartographer villager will cause game to stop ticking.
 * Obtain Explorer Map from command will cause extreme glitching which may cause a crash.
 * Feeding Dolphin will cause it try to swim outside world border.


 * Only double tallgrass and Large fern can generate, due normal grass and fern didn't generate, making savanna less grassy.
 * Caves and ravines will not generate in this world type, making the underground area solid. Rarely, hollow areas will generate.
 * With this world type, the Overworld will be the only dimension that will generate. Attempting to go to other dimensions will result in the portal not being activated.
 * On very rare ocassion, buried treasure can generate in old world type.

Due to structure limitation in this world type, many resources become unobtainable in survival, and some mobs cannot spawn naturally. Because of that, playing survival in this world type will be challenging, due to the structures limitation reduces resources and also affect mobs spawning.

In Old worlds, the Nether and the End cannot be accessed unless the world is converted to the Infinite type, as detailed below.

However, the Nether and End actually exist in this world type but the only way to access these dimensions is via command or  with coresponding portal, just like the Overworld.

Both Nether and End also bordered with size 256x128x256. The Nether still generates normally, but the 8:1 travel ratio is maintained, meaning that returning to the Overworld may cause the player to become stuck (due to the Overworld being only 256x128x256 in size). If nether fortress generated, it will most likely being cutting down by the world border. Despite Nether Portal can't be activated, return from Nether to Overworld will cause newly activated Nether portal to generate in overworld (this is due, nether portal placed with command not counted in overworld). End in old world only generate central island without outer island. sometimes end fountain didn't generate and ender dragon sometimes stuck at border, also end gate way portal didn't work here

Converting to Infinite
To convert an Old world to an Infinite type, select the pencil icon next to the old world in the world selection screen, then select "Make Infinite!". This creates a new world with all of the saved data (inventory, terrain, structures, etc.) of the old world, sets the world type to Infinite, and keeps the world name; the old world is then renamed.

After converting to Infinite, the terrain copied from the old world will have a terrain wall separating it from the added area, as infinite worlds generate larger biomes.

This act is impossible in Minecraft China.