[ALT] Manufactured Moon

[Legend]

Artificial Landscape (Common)
Land
Artificial Landscape enters the battlefield tapped.
T, Sacrifice Artificial Landscape: Add a basic land type to your World. (If you don't control one, create a World land token first.)

Does the reminder text need to denote "colorless" or are tokens automatically colorless unless otherwise denoted? And would it create a land token with the supertype "World" or the subtype "World"? If it creates a land with the "World" subtype (as desired), would that be acceptable considering there is already a "World" supertype?

[user_938036]

Tokens aren't automatically colorless. So you need to specify. Its not advisable to create a subtype that is a supertype. I'm not certain if the rules could handle it but its not advisable to begin with.

The text here is very weird. Can you only have one "world"? The wording "your world" implies that it is intact a singular item that you can't get more of. Like "your library". In yhe end what is a world?

[spacemonaut]

I agree with user_938036. Especially this part:

Its not advisable to create a subtype that is a supertype. I'm not certain if the rules could handle it but its not advisable to begin with.

Yes, creating a subtype with the same name as a supertype is a good path to a bad time. When I say "create a legendary Zombie creature token", but in a world where I've also created legendary as a completely unrelated subtype, how does the player know which one I mean? It's ambiguous, unless we're relying on capitalisation, which we shouldn't because the game isn't case sensitive anywhere else. Also because it needs to be translated into languages which have different capitalisation rules (like German) or no concept of capitalisation at all (like Korean, Japanese, and Chinese).

I'll note that Amass N corresponds to the following rules text:

If you don't control an Army creature, create a 0/0 black Zombie Army creature token. Choose an Army creature you control. Put N +1/+1 counters on that creature.

Unless you bake in very specific rules support for instructions to add types to this specific token type, you may want a keyword action for doing this thing, or you might want to actually spell out what really happens in the ability. It'll be about the same length:

Add a basic land type to your World. (If you don't control one, create a World land token first.)
vs
If you don't control a World land token, create one. Then add a basic land type to your World.