How to create custom new world

[mine_el]

How do i create a new world that does not have random content?

For example, how can i create a new world that is a flat square with no features at all?

[qwertymine3]

There is no map generator to do this currently in minetest - so you need to either find or make a map-gen mod which can do this for you.

If no such mod exists - it should be trivial to make, so I'm sure someone would be willing to make it for you.

[twoelk]

There is no map generator to do this currently in minetest - so you need to either find or make a map-gen mod which can do this for you.
...

ehem...

superflat by srifqi
flatgen by Krock
uniflat by paramat

worldedge by several is usefull to keep players within set limits.
I also use a mod called stay_inside to respawn people that fall of a thin map by mining in wrong places but I can't remember where I got it from. Might have been a script from some discussion or I extracted it from some other mod.

skyplatform by Sokomine might also be interesting

[Wuzzy]

There is also the built-in map generator “singlenode”, its totally not random, everything is air. xD
Just select the map generator “singlenode” when creating a new world.

There is a parameter for singlenode where you can choose to fill the world with something else than air (for example, stone). But I forgot its name. :-(

[Dragonop]

Wuzzy: Or you could just give yourself anything (so the bones will appear), start flying, look for a place to start building, then set home in there, suicide, start building in your bones.

[paramat]

Mgv6 can create a flat world. See end of minetest.conf.example for info on mapgen flags.
In 0.4.13dev there is now a dedicated flat mapgen.