Superflat



Superflat (sometimes called Flatlands) is a World Type, first introduced to Minecraft in Snapshot 12w01a, replacing the normal varied terrain of The Overworld with a thin flat layer of dirt.

The terrain consists of one layer of Bedrock, two layers of Dirt, and one layer of Grass; the surface of the world is completely flat and at height y = 4, with the exception of NPC villages. Since the height limit (256) is unchanged, there is then slightly less than one-third more vertical height available to build above-ground structures as compared to a normal world. Mobs spawn as normal, including Slimes; however, there is no “Void Fog” as would ordinarily be caused by being close to the bottom, even for areas that are completely shielded from sunlight, whether in Survival or Creative Mode.

Because of there being chests in villages, and villages frequently spawning near the spawn point, it is possible to use Superflat as a challenge map. However, the high amount of slimes makes this extremely difficult.

The Nether and The End generate normally; they are not flat. In order to create a Superflat world in SMP, the level-type flag in server.properties must be "FLAT", instead of "DEFAULT".

Future
Jeb considered adding a spawn chest to this world type should the player wish to use it for survival sometime after Minecraft 1.1. Spawning chests are now an option in Snapshot 12w16a and will be released in the 1.3 update.

Resources that can be found in Superflat world
The resources below can always be found, regardless of the "Generate Structures" option.

The resources below can only be found if the "Generate Structures" option is enabled.

Village chests may contain these items:

Bugs

 * If the player breaks the Bedrock barrier, the player can see that the Void has the same color of the sky while the player is above y=0, but looks normal (black) when the player is below y=0.
 * There is no consistent spawn point unless the player has slept in a bed; the player may respawn far from the previous spawning location without anything in sight. This may be due to the lack of ground at the usual height of about 64.
 * Superflat worlds may contain chunk errors that will generate default worlds.
 * If you overwrite a Superflat world with a default world of the same name, some chunks (and sometimes massive areas) may remain Superflat, though the grass color will change with the biome.

Trivia

 * The volume of an entire Superflat world, not including villages, bonus chests, or air, is 3.6 million km3, and the world is composed of 3,600,000,000,000,000 blocks.
 * NPC Villages seem to spawn more frequently on Superflat worlds than normal worlds, due to the fact that the entire world generates as a Plains biome.
 * Slimes spawn in huge numbers in Superflat because they are only four blocks away from the bedrock layer.