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. They can generate with any of the current biomes except roofed forest, mushroom island, mega taiga, Extreme Hills +, mesa F, and birch forest M. However, as a result of their limited size, only a few biomes can be generated per world, also biomes generate in here are shrunken to allow more biome to generate. When creating this world, Player always spawn in the middle of world

Structures Which can generate in overworld in this world type are:
 * villages, only 2 variants which is plains and desert, also never generate as zombie village.
 * desert well, generate normally
 * Grass variants that can generate is only double tall grass and large fern, also both of them generated less than usual.
 * Lake still can generate normally but there are no lava lake generate near bedrock layer, making mining always safe, also lake not generate under Y layer 60.
 * other generated structure such as abandoned mineshaft, ocean monument, woodland mansion, stronghold, dungeon, desert temple, jungle temple, witch hut and igloo not generate, making resources very limited
 * caves and ravine not generate in this world type, so underground in this world is solid, unless hollow rarely generate
 * this world type only have one dimension which is overworld, building nether portal and end portal resulting nothing, as portal cannot be actived, preventing player accessing the Nether and the End

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 Nether and End actually exist in this world type but the only way to access these dimension is via command /setblock or /fill with coresponding portal.just like overworld,

Converting to Infinite
To convert an Old world to an Infinite type, tap on the pencil icon next to the old world in the world selection screen, then tap "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.