Map exchange string format
This is a technical description of the map exchange string format, used to share map generating configurations with other users.
Factorio line wraps the entire map exchange string after 55 characters during export, but ignores all whitespace during import. The outer layer of the map exchange string format includes three angle brackets on either side: ">>>" and "<<<", which must be present for Factorio to accept the string. Between those two tokens is the map exchange data, encoded using base 64 as defined by RFC 4648 (or 3548, 2535, 2045, 1421, et al).
This document will use the terms "int" to refer to 4 byte numbers and "short" to refer to 2 byte numbers. All numerical values are stored in unsigned little-endian format. "boolean" is a single byte that represents true if equal to 1, otherwise it is equal to false. "string"s are Pascal-style int length prefixed strings. The format described below is valid at least for Factorio 0.14.x, older versions may use a different encoding scheme.
Factorio 0.14 and Beyond
This is the base map exchange string format for all Factorio versions 0.14.x and greater.
| Type | Description |
|---|---|
| short[4] | The version string of Factorio that generated this string, used to determine encoding format. |
| byte[*] | Map Gen Settings. Variable length. See linked section for information on how to parse. |
| byte[*] | 0.15.x Map Settings. If present, this chunk consists of the remainder of the data (minus the checksum). |
| int | CRC32 checksum of all preceding data, as defined by ANSI X3.66 / FIPS 71 / ITU-T V.42 (the same one used by zlib, ethernet, etc.) |
Map Gen Settings
This format is very similar to, but not identical to, MapGenSettings - it is missing both the "terrain_segmentation" and "shift" fields.
For the purpose of the "autoplace_controls" field, a dictionary is an array-like structure, where the number of dictionary entries are encoded at the beginning of the dictionary as an integer (int). Following is a sequence of (key, value) pairs, with the specified data types - e.g. a dictionary[string, int] would consist of a sequence of (string, int) pairs.
| Type | LUA key | Description |
|---|---|---|
| byte | Water frequency. | |
| byte | water | Water size. |
| dict<string, byte[3]> | autoplace_controls | An dictionary of Autoplace Controls, with string keys, where the key represents the ore name. Factorio doesn’t care what order this dictionary is in, but it always alphabetizes during export. Vanilla has seven resources: coal, copper-ore, crude-oil, enemy-base, iron-ore, stone, and uranium-ore. Unknown ores are ignored and missing ores are set to their defaults. |
| int | seed | Map seed. |
| int | width | Map width. |
| int | height | Map height. |
| byte | starting_area | Starting area size. |
| boolean | peaceful_mode | Peaceful mode. Enabled if set to 1, disabled otherwise. |
0.15 Map Settings
All of the following data fields (until noted at the end) have a special encapsulation format. Preceding each value is a single byte that states whether or not the value is present. If the byte is equal to zero, then the field value is not present. Otherwise, then the field's value follows. In this section, the data type "double" refers to the 64-bit floating point format described by IEEE 754.
In the LUA structure, this information is stored in the "game.map_settings" table, which is created by the "MapSettings" prototype. Each section in the table below represents a nested sub-table in "map-settings", where the LUA key listed is the key of the table, and all subsequent fields are part of the sub-table. See data/base/prototypes/map-settings.lua for a description of all attributes.
Fields marked with a check (✓) in the "GUI" column are configurable in the new game map generator GUI.
| Type | GUI | LUA key | Description |
|---|---|---|---|
| * | ✓ | pollution | Pollution |
| boolean | ✓ | enabled | Pollution enabled. |
| double | ✓ | diffusion_ratio | The amount of pollution that is diffused into neighboring chunk per second. |
| double | min_to_diffuse | This many PUs must be on the chunk to start diffusing. | |
| double | ✓ | ageing | [Modifier of] the pollution eaten by a chunks tiles. |
| double | expected_max_per_chunk | Anything bigger than this is visualised as this value. | |
| double | min_to_show_per_chunk | Anything lower than this (but > 0) is visualised as this value. | |
| double | ✓ | min_pollution_to_damage_trees | Any pollution above this amount starts to damage trees. |
| double | pollution_with_max_forest_damage | ??? | |
| double | pollution_per_tree_damage | ??? | |
| double | ✓ | pollution_restored_per_tree_damage | The amount of pollution absorbed by a tree when it is damaged by pollution. |
| double | max_pollution_to_restore_trees | ??? | |
| * | steering.default | Steering (Default) | |
| double | ??? | ??? | |
| double | ??? | ??? | |
| double | separation_force | ??? | |
| boolean | force_unit_fuzzy_goto_behavior | ??? | |
| * | steering.moving | Steering (Moving) | |
| double | ??? | ??? | |
| double | ??? | ??? | |
| double | separation_force | ??? | |
| boolean | force_unit_fuzzy_goto_behavior | ??? | |
| * | ✓ | enemy_evolution | Evolution |
| boolean | ✓ | enabled | Evolution enabled. |
| double | ✓ | time_factor | Percent increase in the evolve factor for every second. |
| double | ✓ | destroy_factor | Percent increase in the evolve factor for every destroyed spawner. |
| double | ✓ | pollution_factor | Percent increase in the evolve factor for every 1000 PU [produced]. |
| * | ✓ | enemy_expansion | Enemy Expansion |
| boolean | ✓ | enabled | Enemy expansion enabled. |
| int | ✓ | max_expansion_distance | Distance in chunks from the furthest base around. |
| int | friendly_base_influence_radius | ??? | |
| int | enemy_building_influence_radius | ??? | |
| double | building_coefficient | Expansion algorithm. See LUA file for details. | |
| double | other_base_coefficient | ||
| double | neighbouring_chunk_coefficient | ||
| double | neighbouring_base_chunk_coefficient | ||
| double | max_colliding_tiles_coefficient | A chunk has to have at most this much percent unbuildable tiles for it to be considered a candidate. | |
| int | ✓ | settler_group_min_size | Size of the group that goes to build new base (in game this is multiplied by the evolution factor). |
| int | ✓ | settler_group_max_size | |
| int | ✓ | min_expansion_cooldown | Minimum cooldown. |
| int | ✓ | max_expansion_cooldown | Maximum cooldown. |
| * | unit_group | Unit Group | |
| int | min_group_gathering_time | ??? | |
| int | max_group_gathering_time | ??? | |
| int | max_wait_time_for_late_members | ??? | |
| double | max_group_radius | ??? | |
| double | min_group_radius | ??? | |
| double | max_member_speedup_when_behind | ??? | |
| double | max_member_slowdown_when_ahead | ??? | |
| double | max_group_slowdown_factor | ??? | |
| double | max_group_member_fallback_factor | ??? | |
| double | member_disown_distance | ??? | |
| int | tick_tolerance_when_member_arrives | ??? | |
| int | max_gathering_unit_groups | ??? | |
| int | max_unit_group_size | ??? | |
| * | path_finder | Path Finder | |
| int | fwd2bwd_ratio | ??? | |
| double | goal_pressure_ratio | ??? | |
| bool | use_path_cache | ??? | |
| double | max_steps_worked_per_tick | ??? | |
| int | short_cache_size | ??? | |
| int | long_cache_size | ??? | |
| double | short_cache_min_cacheable_distance | ??? | |
| int | short_cache_min_algo_steps_to_cache | ??? | |
| double | long_cache_min_cacheable_distance | ??? | |
| int | cache_max_connect_to_cache_steps_multiplier | ??? | |
| double | cache_accept_path_start_distance_ratio | ??? | |
| double | cache_accept_path_end_distance_ratio | ??? | |
| double | negative_cache_accept_path_start_distance_ratio | ??? | |
| double | negative_cache_accept_path_end_distance_ratio | ??? | |
| double | cache_path_start_distance_rating_multiplier | ??? | |
| double | cache_path_end_distance_rating_multiplier | ??? | |
| double | stale_enemy_with_same_destination_collision_penalty | ??? | |
| double | ignore_moving_enemy_collision_distance | ??? | |
| double | enemy_with_different_destination_collision_penalty | ??? | |
| double | general_entity_collision_penalty | ??? | |
| double | general_entity_subsequent_collision_penalty | ??? | |
| int | max_clients_to_accept_any_new_request | ??? | |
| int | max_clients_to_accept_short_new_request | ??? | |
| int | direct_distance_to_consider_short_request | ??? | |
| int | short_request_max_steps | ??? | |
| double | short_request_ratio | ??? | |
| int | min_steps_to_check_path_find_termination | ??? | |
| double | start_to_goal_cost_multiplier_to_terminate_path_find | ??? | |
| Note: The following fields do not use the special encapsulation method. | |||
| byte[4] | . (root) | Other | |
| int | max_failed_behavior_count | ??? | |
| Type | GUI | LUA key | Description |
Difficulty Settings
This information is instead stored in the LUA structure at game.difficulty_settings, which is prototyped by DifficultySettings. These fields do not use the special encapsulation method noted above.
| Type | GUI | LUA key | Description |
|---|---|---|---|
| byte[10] | ✓ | difficulty_settings | Difficulty Settings |
| byte | ✓ | recipe_difficulty | Recipe difficulty. 0 for Normal, 1 for Expensive. |
| byte | ✓ | technology_difficulty | Technology difficulty. 0 for Normal, 1 for Expensive. |
| double | ✓ | technology_price_multiplier | Technology price multiplier. |
Autoplace Control
See the page on world generation for more information on frequency, size, and richness.
| string | Ore name. |
| byte | Ore frequency. |
| byte | Ore size. |
| byte | Ore richness. |
Map Gen Size
These are the values used for the frequencies, sizes, and richnesses of ores, water, and the starting area size. None is a valid value for all three options.
| 0 | None / None /None |
| 1 | Very Low / Small / Poor |
| 2 | Low / Small / Poor |
| 3 | Normal / Medium / Regular |
| 4 | High / Big / Good |
| 5 | Very High / Big / Good |
Each of the values in a triplet (such as "low", "small", and "poor") are synonymous.