Maps

A map is the patch of English countryside your airfield is built on: the shape of the ground, the fields and roads painted on it, the trees and rocks, anything already standing there, plus a few settings such as the start date and the crew you begin with. Every map is one file ending in .goamap.

You build maps with the Map Editor that comes with the game, and you ship them in a mod's Maps/ folder. A map can also decide which missions may turn up on it (through tags) and which quest line it starts with.

Quick start

In the main menu, click Map Editor, then New Map. Shape the ground, paint it, place some trees.
Open Map settings and fill in at least Name of Location. Save the map with Save as... and call it my_airfield.
The editor writes my_airfield.goamap into the Maps folder inside your game data folder (the folder that also holds Mods/, see the table below).

Copy that file into a mod with a config.json:

Mods/
  my_map_mod/
    config.json
    Maps/
      my_airfield.goamap

Open Main menu → Mods and press Refresh so the game finds the new mod folder, make sure my_map_mod is switched on, then start a new game. Your map is listed under Custom maps.

That is a complete map mod. The config.json gives the mod its id and name, as every mod needs (see How mods work).

Platform	Game data folder (holds `Mods/` and `Maps/`)
Windows	`%USERPROFILE%\AppData\LocalLow\Blindflug Studios\Ground Of Aces\`
macOS	`~/Library/Application Support/Blindflug Studios/Ground Of Aces/`

Tip

Give the file a name nobody else will pick, for example with your mod's name in front: my_map_mod_airfield.goamap. The file name is the map's id (see Map ids).

The Map Editor

Click Map Editor in the main menu. A window lets you start a New Map or load an existing one.

The editor has a tool for each part of the map:

Tool	What you do with it
Terrain Height	Raise and lower the ground.
Biomes	Paint the ground type: grass, dirt, road, rock, sand, gravel. The ground type also affects gameplay, see Biomes.
Grass	Paint grass on the ground, or remove it.
Terrain Objects	Place trees, bushes, rocks, ponds and so on, one by one or with a brush.
Map settings	The name, description, tags, starting quests, start date and starting supplies of the map (see below).

Undo and Redo work as you would expect. The editor lists its keyboard shortcuts under Shortcuts.

Saving

Save writes over the map you loaded, Save as... asks for a new name. Maps are saved into the Maps folder in your game data folder.

The shipped maps and maps that come from a mod are write-protected: you can load them in the editor, but you can only store your changes with Save as... under a new name. To update a map in your mod, edit the copy in your Maps folder and copy it over the one in Mods/<your mod>/Maps/ again.

Map settings

Every field in Map settings is stored in the map's Metadata.json (see Reference):

Field in the editor	Key in `Metadata.json`	Notes
Name of Location:	`Name`	Shown in the map list.
Description:	`Description`	Shown when the map is selected.
Tags	`_tags`	Comma-separated: `default, my_campaign`. Decides which missions may appear, see Tags and missions.
Starting Quest	`StartingQuestIds`	Comma-separated quest ids: `quest0, my_first_quest`. See Starting quests.
Designation	`AirplaneDesignation`	The squadron code used in your aircraft designations, for example `DB`.
Coordinates	`Coordinates`	Latitude and longitude of the airfield.
Starting Date (dd.mm.yyyy)	`StartDatetime`	Day first, digits and dots only: `15.08.1940`. The time of day is kept.
Amount of Crew Members:	`InitialCrewCount`	Crew you start with.
Resource list	`InitialResources`	Supplies in stock at the start.

In the comma-separated fields, spaces around the commas are ignored and empty entries are dropped.

What is inside a `.goamap`

A .goamap file is an ordinary zip archive with a different ending. Rename a copy to .zip (or open it with any archive tool such as 7-Zip) and you see:

File	What it holds
`Metadata.json`	Name, description, tags, starting quests, dates, starting supplies. The only file you should edit by hand.
`Icon.png`	The picture shown for the map.
`Heightmap.bytes`	The shape of the ground.
`TerrainBiomeTexture.png`	Which ground type is painted where.
`TerrainGrassTexture.png`	Where grass grows.
`TerrainObjects.json`	Trees, rocks, bushes and other terrain objects.
`Props.json`, `Buildings.json`, `Roof.json`, `Workbenches.json`, `TrainingObjects.json`, `FunctionAreas.json`	Everything already built on the map.
`Airplanes.json`, `Characters.json`	Aircraft and people placed on the map.

Leave everything except Metadata.json to the Map Editor.

Editing `Metadata.json` by hand

You can change tags and starting quests without opening the editor:

Open the .goamap with an archive tool.
Extract Metadata.json, edit it in a text editor, and put it back into the archive under the same name.
Keep the archive's file name and the .goamap ending.

Here are the keys you would typically touch, with a tag and a quest line of your own. The real file holds more keys; leave those as they are:

{
  "Name": "Little Snoring",
  "Description": "A grass strip in Norfolk, two fields and a pub.",
  "AirplaneDesignation": "LS",
  "_tags": [
    "my_campaign"
  ],
  "StartingQuestIds": [
    "my_campaign_arrival"
  ]
}

Warning

Keep the file valid JSON: no comments, no trailing commas. A map whose Metadata.json cannot be read is left out of the map list.

Tags and missions

Tags are free-form labels that link maps and missions. A map lists the tags it supports in _tags, a mission lists the tags it is written for in its own _tags, and the mission can only appear on the map when the two lists share at least one tag.

Tags ignore capitalisation: My_Campaign and my_campaign match.
A missing or empty list counts as the single tag default, on the map and on the mission alike.
Every shipped map lists default and its own name: debden, duxford, lichfield, perranporth. So an untagged mission appears on all of them, and a mission tagged only duxford appears only on Duxford.

What that means for your map:

Your map's `_tags`	Missions that can appear
missing or `[]`	Every untagged mission and every mission tagged `default`.
`["default", "my_campaign"]`	All of the above, plus missions tagged `my_campaign`.
`["my_campaign"]`	Only missions tagged `my_campaign`. The regular missions stay away.

Tags only affect missions. Quests are not tagged; a map chooses its quests with StartingQuestIds. How to tag a mission is explained in Missions.

Starting quests

StartingQuestIds lists the quests the map hands out when it is loaded, whatever those quests' own requirements say. When the list is missing or empty, the map starts the game's default quest line, quest0, so no map is ever without quests.

"StartingQuestIds": ["my_campaign_arrival"]

As soon as you list your own quest, quest0 is no longer started on that map, and the shipped main quest line stays away. If you want both, list both:

"StartingQuestIds": ["quest0", "my_campaign_arrival"]

An id that no quest file provides is skipped; the map still loads. How to write the quests themselves is covered in Quests.

Map ids

A map's id is its file name without .goamap. my_airfield.goamap has the id my_airfield, and saves remember the map by that id.

Only files directly inside Maps/ are read. Subfolders are ignored.
Two maps with the same id do not both appear. The one read last replaces the other. Maps are read in this order: the shipped maps, the enabled mods in load order, then your own Maps folder next to Mods, which wins over every mod. So a mod map named Debden.goamap replaces the shipped Debden. Pick a unique name unless that is exactly what you want.
If a mod map replaces a map, saves made on that map load the mod's version.

Seeing your changes

You changed...	To see it
A map file inside a mod the game already knows	Switch the mod off and on again in Main menu → Mods. Maps are re-read at once.
A new mod folder, or a `Maps/` folder that was empty when the game started	Press Refresh in the Mods window, or restart the game.
A map you saved in the Map Editor	Nothing to do, the map list is re-read when you save.
A `.goamap` in your own `Maps` folder that you edited by hand	Restart the game.

If in doubt, restart the game. More on the test loop in Testing and reloading.

Reference

`Metadata.json` reference

Keys you may edit, by hand or through Map settings:

Key	Type	Default when missing	What it does
`Name`	text	none	Name shown in the map list. Plain text, or a localization key.
`Description`	text	none	Description shown when the map is selected. Plain text, or a localization key.
`_tags`	list of text	`["default"]`	Tags this map supports. Matched against the `_tags` of missions.
`StartingQuestIds`	list of text	`["quest0"]`	Quests handed out when the map loads. An empty list also means `["quest0"]`.
`AirplaneDesignation`	text	none	Squadron code for your aircraft designations.
`Coordinates`	object `{ "x": latitude, "y": longitude }`	none	Where the airfield is on the globe.
`InitialCrewCount`	whole number	`0`	Crew at the start.
`StartDatetime`	date and time, `"1940-08-15T07:00:00"`	15 August 1940, 07:00	When the game starts.
`BaseOpeningDatetime`	date and time	1 August 1940, 00:00	Opening date of the base, shown before the game starts.
`InitialResources`	object, resource name to amount	none	Supplies at the start, for example `{ "Planks": 50, "Fuel": 15 }`.

The editor also writes keys such as CreatedDatetime, ModifiedDatetime, AirCrewCount, AirplanesCount, AirstripsCount, DeliveryTruckWaypoints, ShipmentSpawningLocation and DogSpawnPositions. Leave them as the editor wrote them.

Your own maps can be uploaded to the Steam Workshop straight from the map list in the Map Editor. You do not need to build a mod folder for that: the game creates the config.json for you when it uploads the map. A map that ships with missions, quests or other content goes up as a whole mod from the Mods window. See Steam Workshop.