Lost Cities profile options

A Lost Cities profile controls the world-generation choices a player can select when creating a world. Profiles are JSON files in config/lostcities/profiles; the file name without .json is the profile name. The built-in profiles are written to this directory at startup and make useful examples. Copy one to a new file name to customize it.

The options below are the JSON properties consumed by LostCityProfile. Defaults are the class defaults before a built-in or custom preset applies overrides (for example, the built-in default preset supplies its own icon). Numeric ranges are the limits presented by the configuration model. Chances are fractions: 0 never, 1 always.

Spatial options state their unit explicitly. One chunk is 16x16 blocks horizontally. A block distance is measured in Minecraft block coordinates, while a chunk distance counts chunk positions. Heights and vertical offsets are measured in blocks unless a description names another unit, such as city levels or six-block units.

File format

Options are grouped into five objects. Properties may be omitted, in which case their default is used.

{
  "public": true,
  "lostcity": {
    "description": "My custom profile",
    "landscapeType": "default",
    "buildingChance": 0.3
  },
  "cities": {
    "cityChance": 0.01
  },
  "explosions": {
    "explosionChance": 0.002
  },
  "cityspheres": {},
  "client": {}
}

public is a root-level boolean, not a category option. It defaults to true and controls whether users can select the profile. The generated __readonly__ properties are informational and are ignored when a profile is read.

lostcity

Identity, world, and terrain

Option	Default / values	Meaning
description	"Default generation, common cities, explosions"	Main text shown for the profile.
extraDescription	""	Additional profile information.
warning	""	Warning shown when selecting the profile.
worldStyle	"standard"	World-style asset identifier used to select city styles and parts.
icon	""	Profile-screen icon resource, normally a 64×64 texture path such as textures/gui/icon_default.png.
landscapeType	"default"	Landscape algorithm. Values understood by the enum are default, floating, space, cavern, spheres, and cavernspheres; the normal editor offers the first four.
liquidBlock	"minecraft:water"	Namespaced block used as the profile's liquid. An invalid ID logs an error and falls back to water.
baseBlock	"minecraft:stone"	Namespaced block used as the world-generation base. An invalid ID logs an error and falls back to stone.
groundLevel	71 (2–256)	Base ground Y coordinate, in blocks.
seaLevel	-1 (-1–256)	Sea-level Y coordinate, in blocks; -1 uses the world's default.
bedrockLayer	1 (0–10)	Bedrock-layer height in blocks for applicable landscape types; 0 leaves default bedrock generation in place.
terrainFixLowerMinOffset	-4 (-40–40)	Minimum lower-mesh vertical offset, in blocks, from city base level when raising adjacent terrain.
terrainFixLowerMaxOffset	-3 (-40–40)	Maximum lower-mesh vertical offset, in blocks.
terrainFixUpperMinOffset	-1 (-40–40)	Minimum upper-mesh vertical offset, in blocks, when lowering adjacent terrain.
terrainFixUpperMaxOffset	1 (-40–40)	Maximum upper-mesh vertical offset, in blocks.
avoidWater	false	Replaces all water encountered by Lost Cities generation with air.
editMode	false	Enables the special world-generation edit mode.
generateNether	false	Generates the Nether using the cavern-style Lost Cities generator.

Spawn selection

Option	Default / range	Meaning
spawnBiome	""	Namespaced biome in which the player must spawn; empty imposes no biome restriction.
spawnCity	""	Predefined city in which the player must spawn.
spawnSphere	""	Predefined sphere in which to spawn. <in> selects any sphere; <out> requires a position outside every sphere.
spawnNotInBuilding	false	Requires the spawn position not to be in a building. May be combined with other spawn filters.
forceSpawnInBuilding	false	Requires a building spawn. Do not enable together with spawnNotInBuilding.
forceSpawnBuildings	[]	Allowed building IDs when forceSpawnInBuilding is enabled; empty allows any building. Combined with forceSpawnParts.
forceSpawnParts	[]	Allowed part IDs when forcing a building spawn; empty allows any part.
spawnCheckRadius	200 (1–100000)	Initial search radius in blocks. The search starts at world center and rounds the radius up to complete chunk rings.
spawnRadiusIncrease	100 (1–100000)	Number of blocks added to the search radius after an unsuccessful pass.
spawnCheckAttempts	20000 (1–1000000)	Maximum chunks checked before spawn selection fails.

Buildings, streets, parks, and decay

Option	Default / range	Meaning
buildingChance	0.3 (0–1)	Chance that a city chunk contains a building rather than a street.
buildingMinFloors	0 (0–60)	Minimum floors above ground; 0 still means a ground floor.
buildingMaxFloors	8 (0–60)	Hard cap on floors above ground.
buildingMinFloorsChance	4 (1–60)	Low end of the city-factor-dependent random floor calculation.
buildingMaxFloorsChance	6 (1–60)	High end of the city-factor-dependent random floor calculation.
buildingMinCellars	0 (0–20)	Minimum cellar count; 0 permits no cellar.
buildingMaxCellars	3 (0–20)	Maximum cellar count.
buildingDoorwayChance	0.6 (0–1)	Chance per possible building side and level to create a doorway.
buildingFrontChance	0.2 (0–1)	Chance to use a building's front part when it can face an adjacent street.
parkChance	0.2 (0–1)	Chance that an eligible non-building city section is a park in legacy street generation.
parkElevation	true	Adds an elevation layer to parks.
parkBorder	true	Uses the street block as the base of a park border.
parkStreetThreshold	3 (0–8)	Required surrounding-street count for park generation, in addition to parkChance.
fountainChance	0.05 (0–1)	Chance that a street section contains a fountain.
corridorChance	0.7 (0–1)	Chance a chunk is a corridor candidate; adjacent corridors are also required.
bridgeChance	0.7 (0–1)	Legacy bridge candidate chance; connections and terrain impose further conditions.
plannedPrimaryBridgeChance	1.0 (0–1)	Chance that an entire eligible hierarchical primary-road water crossing becomes a bridge.
plannedPrimaryBridgeMaxLength	12 (1–64)	Longest water gap, in chunks, eligible for such a primary-road bridge.
bridgeSupports	true	Generates bridge supports where needed. Disable for bridges intended to cross void.
multiUseCorner	false	Uses only a multi-building's top-left corner level instead of its surrounding average level.
useAvgHeightmap	false	Derives normal city level from surrounding heightmaps. This needs extra heightmap lookups and is slower.
scatteredChanceMultiplier	1.0 (0–100)	Multiplier for scattered-building chances; 0 disables them.
vineChance	0.009 (0–1)	Chance that an exterior building block receives a vine.
randomLeafBlockChance	0.1 (0–1)	Chance of leaf blocks along building/street borders.
randomLeafBlockThickness	2 (1–8)	Side-visible frequency/thickness of those leaf blocks.
avoidFoliage	false	Removes trees and flowers from parks.
rubbleLayer	true	Enables the overgrown rubble dirt/stone/sand and leaf layers.
rubbleDirtScale	3.0 (0–100)	Noise scale for the rubble dirt layer; smaller is broader and 0 disables it.
rubbleLeaveScale	6.0 (0–100)	Noise scale for the rubble leaf layer; smaller is broader and 0 disables it.
ruinChance	0.05 (0–1)	Chance that a building is ruined.
ruinMinlevelPercent	0.8 (0–1)	Minimum relative height at which a ruined building's destruction begins.
ruinMaxlevelPercent	1.0 (0–1)	Maximum relative height at which destruction begins.

The random floor bound is based on buildingMinFloorsChance + (cityFactor + 0.1) × (buildingMaxFloorsChance - buildingMinFloorsChance), added to buildingMinFloors as a random amount and capped by buildingMaxFloors.

Several city-local profile values have long-standing city-style overrides. After city-style inheritance, buildingsettings.buildingchance, its floor/cellar limits, parkblocks.parkchance, avoidfoliage, parkborder, parkelevation, parkstreetthreshold, streetblocks.fountainchance, frontchance, and corridorblocks.corridorchance override their corresponding profile fallbacks. Floor and cellar values remain additional constraints rather than simple replacements. The effective settings resolver does not mutate the selected profile.

Hierarchical street generation

These options other than streetGenerationMode apply to HIERARCHICAL_GRID_V1. The selected mode is copied into persistent world data when a world is initialized; changing the profile later does not change an existing world's mode.

Option	Default / values	Meaning
streetGenerationMode	HIERARCHICAL_GRID_V1	LEGACY or HIERARCHICAL_GRID_V1.
openLotParkChance	0.8 (0–1)	Chance that a hierarchical grass open lot receives a weighted park part. City-style profile_overrides.openLotParkChance overrides it after inheritance; legacy parkblocks.parkchance remains independent.
primaryRoadSpacingX	8 (8–128)	Number of chunks between candidate north/south primary corridors (lines at fixed X coordinates). A candidate is not necessarily enabled.
primaryRoadSpacingZ	8 (8–128)	Number of chunks between candidate east/west primary corridors (lines at fixed Z coordinates). A candidate is not necessarily enabled.
primaryRoadOptionalChance	0.45 (0–1)	Independent chance that each non-forced candidate becomes an actual primary corridor. 0 omits all non-forced candidates; 1 enables every candidate.
primaryRoadForceEvery	4 (1–16)	Enables every Nth candidate on both axes regardless of primaryRoadOptionalChance. Thus the maximum separation between enabled primary corridors is N × the corresponding spacing. A value of 1 enables every candidate.
secondaryRoadMinCountX	0 (0–128)	Minimum requested internal north/south secondary roads in each primary block.
secondaryRoadMaxCountX	2 (0–128)	Maximum requested internal north/south secondary roads. Must be at least the minimum.
secondaryRoadMinCountZ	0 (0–128)	Minimum requested internal east/west secondary roads.
secondaryRoadMaxCountZ	2 (0–128)	Maximum requested internal east/west secondary roads. Must be at least the minimum.
minimumRoadSeparation	4 (2–32)	Minimum chunk distance between parallel secondary roads selected within the same primary block. It does not constrain tertiary roads.
minimumRoadEdgeDistance	3 (2–32)	Minimum chunk distance from a secondary road to its bounding primary road.
tertiaryRoadChance	0.4 (0–1)	Chance that a subdivided block gets one short tertiary access road.
tertiaryRoadMinLength	2 (1–16)	Minimum tertiary-road length in chunks.
tertiaryRoadMaxLength	5 (1–32)	Maximum tertiary-road length; must be at least the minimum.
multiBuildingStreetConflict	OVERRIDE_MINOR	Planned-road policy for random multi-buildings: BLOCK_ALL lets every road block them; OVERRIDE_MINOR lets only primary roads block them; OVERRIDE_ALL lets multi-buildings replace any road. Ignored in legacy mode.

Primary-road spacing first creates a regular set of candidate corridors. primaryRoadOptionalChance randomly but deterministically enables non-forced candidates, while primaryRoadForceEvery guarantees that the gaps cannot grow indefinitely. For example, with both spacing values set to 12 and primaryRoadForceEvery also set to 12, candidates occur every 12 chunks, but only every twelfth candidate is guaranteed: forced corridors are 144 chunks apart. Optional candidates between them may become corridors according to primaryRoadOptionalChance. The spacing and force values would describe the same interval only when primaryRoadForceEvery is 1.

Secondary-road counts are requests rather than guarantees. If a primary block cannot fit the selected count while respecting minimumRoadSeparation and minimumRoadEdgeDistance, the planner places as many secondary roads as fit.

Highways

LEGACY uses the Perlin and distance-mask options. INTERCITY_NETWORK_V1 uses the hub/network options. Like the street mode, the highway mode is selected and persisted when a new world is initialized.

Option	Default / values	Meaning
highwayGenerationMode	INTERCITY_NETWORK_V1	LEGACY or INTERCITY_NETWORK_V1.
highwayRequiresTwoCities	true	Legacy highways require a valid city at both ends; false requires only one.
highwayLevelFromCities	3 (0–4)	Shared height rule: 0 first endpoint, 1 lower endpoint, 2 higher endpoint, 3 integer endpoint average, 4 fixed highwayNetworkLevel.
highwayDistanceMask	7 (≥0)	Legacy highway spacing bitmask applied to chunk coordinates; it is not a block distance. Use a power of two minus one; 0 disables legacy highways.
highwayMainPerlinScale	50.0 (1–1000)	Legacy main-axis noise scale applied to chunk coordinates. Higher values produce more frequent, shorter highways.
highwaySecondaryPerlinScale	10.0 (1–1000)	Legacy secondary-axis noise scale applied to chunk coordinates, controlling variation among nearby highways.
highwayPerlinFactor	2.0 (-100–100)	Legacy noise threshold. 0 is roughly 50%; a high value suppresses highways. Legacy candidates occur only on chunks divisible by eight.
highwaySupports	true	Generates supports where needed; disable for highways spanning void.
highwayPlanningCellSize	128 (32–512)	Planning-cell size in chunks for the intercity network.
highwayHubSampleSpacing	16 (1–512)	Chunk spacing between deterministic city-potential samples in a cell; cannot exceed planning-cell size. Samples include terrain-height and biome-multiplier checks.
highwayHubMinimumPotential	0.20 (0–1)	Minimum height- and biome-adjusted city-potential score needed to create a hub. Lower values make inter-city highway hubs more common.
highwayHubSearchRadiusCells	2 (0–8)	Planning-cell radius in which a hub considers other hubs.
highwayMinimumHubDistance	64 (0–4096)	Minimum Euclidean distance in chunks between connected hubs.
highwayMaximumHubDistance	320 (0–4096)	Maximum connected-hub distance; cannot be below the minimum.
highwayMaximumConnectionsPerHub	2 (1–8)	Maximum intercity connections incident to one hub.
highwayMinimumRouteLength	40 (0–4096)	Minimum Manhattan route length in chunks.
highwayRouteCityPenalty	1.0 (0–1000)	Weight of approximate city potential when selecting an L-shaped route's bend.
highwayNetworkLevel	0 (0–32)	Fixed highway level used when highwayLevelFromCities is 4.

Railways, loot, and generation details

Option	Default / range	Meaning
railwayDungeonChance	0.01 (0–1)	Chance that a chunk next to a railway gets a railway dungeon.
railwaysCanEnd	false	Allows an ending rail part where a missing city would otherwise have supplied a station. Useful with rare cities.
railwaysEnabled	true	Enables rail lines. Stations are controlled separately and may still generate when this is false.
railwayStationsEnabled	true	Enables railway stations.
railwaySurfaceStationsEnabled	true	Enables surface stations; false restricts generation to underground stations.
generateSpawners	true	Allows configured spawners in buildings.
generateLoot	true	Allows configured loot in building chests.
generateLighting	false	Adds minimal building lighting.
chestWithoutLootChance	0.2 (0–1)	Chance that an otherwise eligible chest is empty.
buildingWithoutLootChance	0.2 (0–1)	Chance that a building has neither loot nor spawners.

cities

Option	Default / range	Meaning
cityChance	0.01 (-1–1)	Chance that a chunk becomes a city center. Exactly -1 selects the Perlin rarity variant.
cityMinRadius	50 (1–2000)	Minimum city radius in blocks when using random city centers.
cityMaxRadius	128 (1–2000)	Maximum city radius in blocks.
cityPerlinScale	3.0 (-1000000–1000000)	Rarity-map scale applied to chunk coordinates when cityChance is -1.
cityPerlinInnerScale	0.1 (-1000000–1000000)	Internal rarity-map scale applied to chunk coordinates in Perlin mode.
cityPerlinOffset	0.1 (-1000000–1000000)	Dimensionless rarity-map value offset in Perlin mode; it is not a spatial offset.
cityThreshold	0.2 (0–1)	City-factor threshold at which overlapping city circles count as city.
citySpawnDistance1	0 (0–10000000)	First distance from spawn, in blocks, for city-factor scaling.
citySpawnMultiplier1	1.0 (0–1)	City-factor multiplier at and below the first distance.
citySpawnDistance2	0 (0–10000000)	Second distance from spawn, in blocks; 0 disables spawn-distance scaling. Between distances the multiplier is interpolated.
citySpawnMultiplier2	1.0 (0–1)	City-factor multiplier at and beyond the second distance.
cityStyleThreshold	-1 (disabled; editor range 0–1)	Uses cityStyleAlternative when city factor falls below this threshold. The default disables the switch.
cityStyleAlternative	""	Alternative city-style identifier used with cityStyleThreshold.
cityAvoidVoid	true	In floating landscapes, suppresses city chunks detected as void, avoiding cities on island edges.
cityLevel0Height	75 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 0.
cityLevel1Height	83 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 1.
cityLevel2Height	91 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 2.
cityLevel3Height	99 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 3.
cityLevel4Height	107 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 4.
cityLevel5Height	115 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 5.
cityLevel6Height	123 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 6.
cityLevel7Height	131 (1–384)	Chunks below this terrain Y coordinate, in blocks, use city level 7.
cityMinHeight	50 (-1024–2048)	No cities generate below this terrain Y coordinate, in blocks.
cityMaxHeight	150 (-1024–2048)	No cities generate above this terrain Y coordinate, in blocks.
oceanCorrectionBorder	4 (-255–255)	Vertical terrain-correction offset, in blocks, for ocean-biome chunks adjacent to cities.

explosions

The normal and mini systems are independent. Radius is in blocks and height is a Y coordinate.

Option	Default / range	Meaning
explosionChance	0.002 (0–1)	Per-chunk chance of a normal explosion.
explosionMinRadius	15 (1–1000)	Minimum normal explosion radius in blocks.
explosionMaxRadius	35 (1–3000)	Maximum normal explosion radius in blocks.
explosionMinHeight	75 (1–256)	Minimum normal explosion-center Y coordinate, in blocks.
explosionMaxHeight	90 (1–256)	Maximum normal explosion-center Y coordinate, in blocks.
miniExplosionChance	0.03 (0–1)	Per-chunk chance of a mini explosion.
miniExplosionMinRadius	5 (1–1000)	Minimum mini explosion radius in blocks.
miniExplosionMaxRadius	12 (1–3000)	Maximum mini explosion radius in blocks.
miniExplosionMinHeight	60 (1–256)	Minimum mini explosion-center Y coordinate, in blocks.
miniExplosionMaxHeight	100 (1–256)	Maximum mini explosion-center Y coordinate, in blocks.
explosionsInCitiesOnly	true	Requires blast centers to be in cities, although damage may extend outside them.
debrisToNearbyChunkFactor	200 (1–10000)	Controls debris spilling from nearby damaged chunks; larger values produce less spillover.

cityspheres

These settings primarily affect sphere-based landscape types. Options mentioning an outside world control terrain beyond a sphere.

Option	Default / range	Meaning
citySphereFactor	1.2 (0.1–10)	In space, multiplier from city radius to outer glass-sphere radius.
citySphereChance	0.7 (0–1)	Chance that a city gets a sphere.
citySphereClearAbove	0 (0–1024)	Blocks cleared above the top sphere glass; 0 disables clearing.
citySphereClearAboveUntilAir	false	After the fixed clearing, continues upward until air is reached.
citySphereClearBelow	0 (0–1024)	Blocks cleared below the sphere top; 0 disables clearing.
citySphereClearBelowUntilAir	false	After the fixed clearing, continues downward until air is reached.
sphereSurfaceVariation	1.0 (0–1)	Surface variation inside spheres; smaller values make terrain more varied.
outsideSurfaceVariation	1.0 (0–1)	Surface variation outside spheres; smaller values make terrain more varied.
monorailChance	0.8 (0–1)	Chance of requesting a monorail in each direction. A connection needs a sphere at the other end that also requests it.
monorailOffset	-2 (-100–100)	Monorail vertical offset in blocks relative to the main sphere height.
onlyPredefined	false	Generates only spheres supplied by predefined assets.
outsideProfile	""	Optional profile name used to generate the world outside spheres.
outsideGroundLevel	-1 (-1–256)	Deprecated. Outside ground Y coordinate in blocks; use the groundLevel of outsideProfile instead.
grid32	false	Aligns sphere centers to a 32×32 chunk grid instead of a 16×16 grid.

client

These options have an effect only when the client has Lost Cities installed. -1 leaves the vanilla/default value unchanged.

Option	Default / range	Meaning
horizon	-1 (-1–256)	Client horizon height.
fogRed	-1 (-1–1)	Red fog component; normal explicit colors use 0–1.
fogGreen	-1 (-1–1)	Green fog component.
fogBlue	-1 (-1–1)	Blue fog component.
fogDensity	-1 (-1–1)	Fog density override.

Validation and compatibility notes

• Minimum values must not exceed their corresponding maximums for secondary-road counts, tertiary-road lengths, or highway hub distances.
• highwayHubSampleSpacing cannot exceed highwayPlanningCellSize.
• Mode names and conflict-policy names are case-insensitive when read, but the generated profiles use the uppercase enum names shown above.
• Profile defaults and available options can change between mod versions. Keep custom profiles under version control and compare them with a newly generated default profile after upgrading.

Common profile recipes

The snippets below contain only the relevant sections. Merge them into a copy of a generated profile rather than using them as complete profile files. Try changes in a new world first: generated chunks are not rebuilt, and an existing world's persisted street and highway generation modes do not change when the corresponding mode option is edited.

Make cities rarer but larger

Lower cityChance to create fewer city centers, then raise both radius bounds to make each resulting city cover more ground:

{
  "cities": {
    "cityChance": 0.003,
    "cityMinRadius": 100,
    "cityMaxRadius": 240
  }
}

These values are a starting point, not an equivalent exchange: larger cities can overlap, so inspect several seeds and tune cityChance first. Keep cityMinRadius below cityMaxRadius.

Increase or decrease inter-city highways

For INTERCITY_NETWORK_V1, highwayHubMinimumPotential is the closest control to highway frequency. Lower it to let weaker city regions become hubs; raise it to require stronger city regions. Adjust it in steps of about 0.05. highwayMaximumConnectionsPerHub separately controls how many routes a hub can have.

For example, this makes a denser network:

{
  "lostcity": {
    "highwayGenerationMode": "INTERCITY_NETWORK_V1",
    "highwayHubMinimumPotential": 0.15,
    "highwayMaximumConnectionsPerHub": 3
  }
}

For fewer highways, try a threshold of 0.30 and leave the connection limit at 2, or set it to 1 for a very sparse network. A value of 0 for highwayHubSearchRadiusCells prevents hubs from finding neighbors and therefore disables inter-city routes.

Increase or decrease legacy highways

For LEGACY, lower highwayPerlinFactor to make candidates more common and raise it to make them rarer. highwayDistanceMask controls the candidate-line spacing and must be a power of two minus one; 7, 15, and 31 produce progressively wider spacing, while 0 disables legacy highways.

{
  "lostcity": {
    "highwayGenerationMode": "LEGACY",
    "highwayPerlinFactor": 1.5,
    "highwayDistanceMask": 7,
    "highwayRequiresTwoCities": false
  }
}

Allowing one city endpoint with highwayRequiresTwoCities: false is especially useful in rare-city profiles.

Make the city street grid denser

These settings enable every primary-road candidate, request more secondary roads inside each primary block, and make tertiary access roads more likely:

{
  "lostcity": {
    "streetGenerationMode": "HIERARCHICAL_GRID_V1",
    "primaryRoadSpacingX": 8,
    "primaryRoadSpacingZ": 8,
    "primaryRoadOptionalChance": 1.0,
    "primaryRoadForceEvery": 1,
    "secondaryRoadMinCountX": 2,
    "secondaryRoadMaxCountX": 3,
    "secondaryRoadMinCountZ": 2,
    "secondaryRoadMaxCountZ": 3,
    "tertiaryRoadChance": 0.8
  }
}

Dense road settings leave fewer building lots. To make a sparser grid, increase both primary spacing values, lower primaryRoadOptionalChance, request fewer secondary roads, and lower tertiaryRoadChance.

Make taller, more building-heavy cities

Raise buildingChance for fewer street or open-lot chunks, then increase the floor bounds. Taller buildings cost more generation and rendering time.

{
  "lostcity": {
    "buildingChance": 0.6,
    "buildingMinFloors": 3,
    "buildingMinFloorsChance": 6,
    "buildingMaxFloorsChance": 12,
    "buildingMaxFloors": 16
  }
}