Explorer Map

An explorer map is a special map used to aid in finding rare generated structures, including woodland mansions, monuments, and buried treasure.

Trading
Journeyman-level Cartographer villagers have a $1/3$ chance to sell ocean explorer maps and $1/3$ chance to sell woodland explorer maps for a compass and 12 emeralds.

Apprentice-level Cartographer villagers sell ocean explorer maps for 13 emeralds and a compass. Journeyman-level Cartographer villagers sell woodland explorer maps for 14 emeralds and a compass.

In Java Edition, if the cartographer is in the Nether or End, either spawned or transported, the trades for the map do not unlock. However, in Bedrock Edition, the cartographer trades for the map are unlocked, but the purchased map shows the same layout as in corresponding dimension and show no destination structure, but if cartographer trades are unlocked in an old world type (prior-1.11.0), the game stops ticking.

Locating structures
There are three types of explorer maps: woodland, ocean, and buried treasure. The maps differ from a normal map, in that it shows the area's land-water outline, as well as an orange striated (striped) texture for areas below sea level, and the blank map texture for land above sea level. The maps show a section of land that contains a woodland mansion, monument or buried treasure respectively. This may not be the nearest such structure to the player. The structures are displayed as a small icon. If the player icon is smaller than it would be on a normal map, that means the player is a great distance away. When the player is less than 1027 blocks away from the map border, the icon returns to the proper size. When the player reaches the map's area of land (512*512), the map fills in like a normal map.

The basic functions of a buried treasure explorer map are similar to that of the other two. However, instead of showing the structure icon on the map, it shows a red X instead. The buried treasure structure is located on the same X and Z coordinates as the middle of the X (the player marker may need to be aligned with the bottom of the middle 2 by 2 pixel square of the X). To locate the chest spot, hold the treasure map with both hands, not in the offhand slot.

Cloning
The parts of the world that have already been explored and mapped are copied, and newly explored areas appear on both instances. In Creative mode, cloned explorer maps can be obtained by pick blocking on the explorer map displayed on item frames (the map needs to be out of the player's inventory when using pick block, or else that map moves into the active hotbar slot).

ID
Explorer maps use the item id of regular maps,  in Java Edition and   in Bedrock Edition.

Item data
An explorer map differs from a map in that its  tag is set, which includes a   and a  ; also its   list includes an entry for its target monument, mansion or buried treasure. Its map item entry is identical to that of a normal map, except that by the time the player sees it, its  byte array is pre-filled with explorer maps' characteristic land-water boundary lines and water shading.

It should be noted that this additional data is stored in the Cartographer's NBT data and in the inventory item's NBT data, and not in the map file (e.g. map_0.dat). If the player were to use the /give command to give themselves a map with the same map ID as an existing explorer map, it would still have the Ocean Monument/Woodland Mansion icon on the map, but it would simply be named "Map" instead of, for example, "Ocean Explorer Map".
 * Item data
 * : How the map looks in an item slot. See also Player.dat_format.
 * : The name the map is given. In this case, they are localized strings: either,  or.
 * : Color codes are calculated from the Red, Green and Blue components using this formula:  Red <<16 + Green <<8 + Blue . Monument maps use 3830373, which is . Mansion maps use 5393476, which is . Buried treasure explorer maps do not use a color code.
 * : One of these for each icon on the map. Explorer maps always have at least one representing their target.
 * : An arbitrary unique string identifying the decoration. For explorer map target structures, this is "+".
 * : The rotation of the icon. For explorer map target structures, this is always 180.
 * : The ID of the map icon: 8 for a mansion map, 9 for a monument map, 26 for a treasure map.
 * : The world x-coordinate of the target structure icon.
 * : The world z-coordinate of the target structure icon.
 * : The world x-coordinate of the target structure icon.
 * : The world z-coordinate of the target structure icon.
 * Notes

In Bedrock Edition, The Item Data value distinguishes explorer maps from one another and from d plain and locator maps:

Trivia

 * When a cartographer generates the trade offers for the explorer maps, it chooses the location of one of the nearest structures of the respective type (monument or woodland mansion).
 * For the reason above, explorer maps obtained from one cartographer are always the same. Also, if two cartographers unlock the explorer map trades approximately at the same place and the same time, the map locations are usually identical. This sometimes also happens when finding multiple treasure maps from underwater ruined villages.
 * Explorer maps fill as the chunks are generated, rather than when the player holds them while in the area; leaving an explorer map while exploring the area still fills the map.
 * Buried treasure explorer maps are named Buried Treasure Map in the Java Edition while in the Bedrock Edition they are named Treasure Map.
 * It is possible for a cartographer to give a monument or woodland mansion explorer map for areas where the structures would have spawned in the world, but were unable to as a result of terrain generation. As a result, explorer maps, unfortunately, don't always guarantee that a structure exists at the purported location. This is most common with woodland mansion explorer maps, due to its generation algorithm.
 * In Legacy Console Edition, a treasure map shows different locations in different worlds generated from the same seed, but one location is valid.