Java Edition:Invalid Dimension Map
During the 2020 April Fools' snapshot 20w14∞, maps could be created in any of the unique dimensions, and, in the 2023 April Fools' snapshot, 23w13a_or_b, you could create a map in the moon dimension.
Obtaining
Regular Maps
These are obtained simply by making a map in a different dimension. Note that most of the dimensions create a nether map, and these are not unique nor distinguishable. Technically any pattern created on one of these maps could be replicated in one of the current dimensions, so there is only one way to separate these maps from normal maps. If the map does not show a white dot in any location in the entire overworld and end dimensions, then it is an invalid dimension map. It is of course practically impossible to check every location of two dimensions.
Explorer Maps
This requires a villager to trade an explorer map in a certain dimensions. These maps are slightly easier to distinguish as unobtainable since they will likely be parallel to an already existing explorer map.
Villagers only trade explorer maps if they can locate either a woodland mansion or ocean monument in a dimension, so this only works for specific dimensions. The listed dimensions below are the only known ones to generate an explorer map trade:
| blacklight |
| blue |
| chess |
| colors |
| darkness |
| decay |
| green |
| holes |
| pillars |
| red |
| rooms |
| skygrid |
| slime |
| wall |
| zones |