Core Keeper Spawn Tiles: Spawn Chances per Tile and Mob Farm Calculator

Spawn tile calculator for mob farms (how many tiles per chunk?)

Choose the spawn tiles you want to place and the enemies you are after. The calculator works out how many tiles of each to place in one chunk (the 16×16 spawn area) so your target enemies spawn in balanced, equal numbers. Choose "2× wanted" or "3× wanted" to get them in that ratio instead.

All selected tiles are mixed into a single chunk for the calculation (the tool is for checking the ratio of spawns). It does not account for enemies that attack each other or how the trap is built, so we don't recommend building a farm that mixes everything as-is.

1Choose the spawn tiles to place (any number)

The 11 tiles selected by default are the ones that work in a battle-royale style farm (enemies fighting each other) in the current version (Ground Slime, Ground Poison Slime, Ground Slippery Slime, Ground Magma Slime, Chrysalis, Clay Moss, Lush Moss, Valley Moss, Crystal Crust, Mold Block, Ravine Coral).

Ground Slime Ground Poison Slime Ground Slippery Slime Ground Magma Slime Chrysalis Stone Moss Clay Moss Lush Moss Urban Moss Valley Moss Crystal Crust Fungal Soil Mossy Soil Rust Pile Muddled Moss Mold Block Ravine Coral

2Choose your target enemies and the ratio you want (set unwanted ones to "Not wanted")

Tiles available for spawn tiles (per chunk, max 256) Number of chunks with the same farm

How it is calculated: each tile rolls for each enemy at that enemy's chance, and the result is the expected value capped by the per-event limit and the density limit. It assumes you clear the enemies from the previous event every time (none left over). Leftover enemies lower the chance (see "How it works" below). The split is chosen to "make the rarest enemy as common as possible": tiles are added one at a time to the floor of whichever enemy is currently lowest (compared after dividing by the wanted ratio).

What are spawn tiles? Floors that spawn enemies for farms

Spawn tiles are floors that can spawn enemies or resources (such as mushrooms) during each periodic spawn event. Place them on any ground and enemies start appearing there. They are used for mob farms (traps) that kill enemies for materials, and for leveling skills.

• If you stack two spawn tiles on the same tile, only the top one counts.
• Light level doesn't affect spawning. However, placing a torch on a tile stops spawns from that tile.
• Placing blocks, walls or furniture on a tile also stops spawns. Conveyor belts and spike traps are fine to place on top.

Mechanics from the Core Keeper Wiki (Fandom) pages "Spawning tiles", "Guides/Mob farming" (CC BY-SA 3.0), not confirmed in the game files.

Spawn tile types: enemies, chances and where to get them

For each spawn tile: the enemies and resources it spawns, and where to get the tile (biomes where it grows naturally, enemies that drop it, and scenes and dungeons where it is placed). The numbers are in the spawn chance tables.

Ground Slime

Spawns

• Orange Slime30%
• Red Slime1%

For rare enemies, place more tiles: Red Slime 12% with 13 tiles, 92% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Undergrounds

Placed in

The Undergrounds: Glurch the Abominous Mass' Arena, Slime Territory, Slime Area, Glurch the Abominous Mass' Dungeon

The Clay Caves: Small Islands, Colossal Cicada Husk Burrow, Slime Territory, Large Larva Territory

The Forgotten Ruins: Small Islands

Mold area: Main Mold Temple, Mold Village

Unknown biome: Caveling Barn, Clay Settlement, Dirt Melody Room

Ground Poison Slime

Spawns

• Purple Slime30%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

Azeos' Wilderness (on Grass Block ground, 0.5% per tile, grows in clusters)

Placed in

Azeos' Wilderness: Abyss Home, Ivy the Poisonous Mass' Arena, Ivy the Poisonous Mass' Dungeon

Unknown biome: Caveling Barn, Nature Melody Room

Ground Slippery Slime

Spawns

• Blue Slime30%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

The Sunken Sea (on any ground, 1% per tile, grows in clusters)

Placed in

The Sunken Sea: Morpha the Aquatic Mass' Arena, Morpha the Aquatic Mass' Dungeon

Forlorn Metropolis: City Sewers

Unknown biome: Sea Melody Room

Ground Magma Slime

Spawns

• Lava Slime30%
• Lava Butterfly10%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

Molten Quarry (Small Molten Quarry, Large Molten Quarry)

Placed in

The Desert of Beginnings: Igneous the Molten Mass' Arena, Ancient Forge Room, Lava Lake, Small Molten Quarry

Unknown biome: Quarry Area, Amalgam Basin, Quarry Boulder Mine, Large Molten Quarry

Chrysalis

Spawns

• Larva30%
• Big Larva1%
• Cocoon1%

For rare enemies, place more tiles: Big Larva 12% with 13 tiles, 92% with 256; Cocoon 12% with 13 tiles, 92% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Clay Caves, Larva Hive (Small Larva Hive, Main Larva Hive)

Placed in

The Clay Caves: Larva Territory, Medium Larva Territory, Abandoned Clay Mineshaft, Strolly Poly Camp, Small Larva Hive

Unknown biome: The Hive Mother's Arena, Caveling Barn, Clay Settlement, Clay Melody Room, Main Larva Hive

Stone Moss

Spawns

• Caveling30%
• Caveling Shaman1%
• Caveling Brute0.5%

For rare enemies, place more tiles: Caveling Shaman 12% with 13 tiles, 92% with 256; Caveling Brute 6% with 13 tiles, 72% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Forgotten Ruins (on Stone Block ground, 0.5% per tile, grows in clusters)

Enemy drop

Caveling Brute 3.9%, Caveling 3.7%, Caveling Shaman 3.3%

Placed in

The Forgotten Ruins: Overgrown Grove, Caveling Ruins, Malugaz the Corrupted's Dungeon

Unknown biome: Stone Melody Room

Clay Moss

Spawns

• Caveling Skirmisher30%
• Caveling Spearman30%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

The Clay Caves (on Clay Block ground, 0.8% per tile, grows in clusters)

Enemy drop

Caveling Skirmisher 4.3%, Caveling Spearman 4.3%

Placed in

The Clay Caves: Strolly Poly Camp, Clay Settlement

Unknown biome: Clay Settlement

Lush Moss

Spawns

• Caveling Gardener30%
• Caveling Hunter30%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

Azeos' Wilderness (on Grass Block ground, 0.5% per tile, grows in clusters)

Enemy drop

Caveling Gardener 4%, Caveling Hunter 3%

Placed in

Mold area: Mold Grass Patch

Azeos' Wilderness: Scarlet Camp, Instrument Room

Urban Moss

Spawns

• Caveling Scholar30%
• Core Sentry0.5%

For rare enemies, place more tiles: Core Sentry 6% with 13 tiles, 72% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

Forlorn Metropolis (Small Forlorn Metropolis, Large Forlorn Metropolis)

Enemy drop

Core Sentry 5%, Caveling Scholar 4.5%

Placed in

The Sunken Sea: Broken City Isle, Small Forlorn Metropolis

Unknown biome: Sea Melody Room, Large Forlorn Metropolis

Valley Moss

Spawns

• Caveling Assassin30%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

The Desert of Beginnings (on Desert Block ground, 0.1% per tile, grows in clusters)

Placed in

The Desert of Beginnings: Oasis Settlement, Ra-Akar the Sand Titan's Dungeon

Unknown biome: Desert Ruins Garden, Desert Ruins Plaza

Crystal Crust

Spawns

• Mimite30%
• Orbital Turret5%

For rare enemies, place more tiles: Orbital Turret 49% with 13 tiles, 100% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Shimmering Frontier (on Crystal Block ground, 0.2% per tile, grows in clusters)

Placed in

The Shimmering Frontier: Alien Material Depot, Crystal Meadow, Crystal Pond, Crystal Forest

Unknown biome: Failed Titan, Alien Challenge Arena, Alien Ring Room

Fungal Soil

Spawns

• Mushroom20%
• Shrooman10%
• Shrooman Brute0.5%

For rare enemies, place more tiles: Shrooman Brute 6% with 13 tiles, 72% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Undergrounds (on Dirt Block ground, 2% per tile, grows in clusters)

Enemy drop

Shrooman 5.4%, Orange Slime 2.3%, Red Slime 2.2%

Placed in

The Undergrounds: Dirt Mushroom Farm

Other

You can dig it up with a hoe and place it elsewhere.

Mossy Soil

Spawns

• Moorshroom20%

How many: every enemy here has a high chance, so about 13 tiles per chunk is enough. Build more in another chunk.

Where to get it

Grows naturally

Moss (an area inside The Forgotten Ruins)

Placed in

The Forgotten Ruins: Moss

Rust Pile

Spawns

• Geobot Scourer1%
• Geobot Miner0.2%
• Geobot Patroller0.2%

For rare enemies, place more tiles: Geobot Scourer 12% with 13 tiles, 92% with 256; Geobot Miner 3% with 13 tiles, 40% with 256; Geobot Patroller 3% with 13 tiles, 40% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

Breaker's Reach (rocky ground, 2% per tile, grows in clusters)

Placed in

Breaker's Reach: Excavation Doorway, Excavation Drill Approach, Excavation Storage, Excavation Town Square, Excavation Gauntlet, Excavation Figurine Puzzle

Unknown biome: Excavation Hallway, Waypoint Room

Muddled Moss

Spawns

• Glowing Mushroom20%
• Void Larva4%
• Void Caveling0.2%
• Void Caveling Brute0.2%
• Void Caveling Shaman0.2%
• Void Larva Cocoon0.2%

For rare enemies, place more tiles: Void Larva 41% with 13 tiles, 100% with 256; Void Caveling 3% with 13 tiles, 40% with 256; Void Caveling Brute 3% with 13 tiles, 40% with 256; Void Caveling Shaman 3% with 13 tiles, 40% with 256; Void Larva Cocoon 3% with 13 tiles, 40% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

Breaker's Reach (void ground, 2% per tile, grows in clusters)
Breaker's Reach (void ground, 5% per tile, single tiles)

Mold Block

Spawns

• Infected Caveling10%
• Mold Tentacle0.5%

For rare enemies, place more tiles: Mold Tentacle 6% with 13 tiles, 72% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

Mold Dungeon (Small Mold Dungeon, Main Mold Dungeon)

Ravine Coral

Spawns

• Wingling3%

For rare enemies, place more tiles: Wingling 33% with 13 tiles, 100% with 256 (chance per spawn event). Details

Where to get it

Grows naturally

The Undergrounds (on any ground, next to pits, 5% per tile, grows in clusters)

Enemy drop

Wingling 5.3%

Natural locations (ground and chance when the world is generated) and enemy drop chances are calculated from the game's config files (Conf folder Spawn/Initial and Loot, version 1.3.0.6). Drop chances are per enemy. "Placed in" (scenes and dungeons), and the area shown for tiles that do not grow naturally, are from the Core Keeper Wiki (Fandom) scene data and spawn tile pages (CC BY-SA 3.0).

Farming rare enemies: how to lay out spawn tiles for low-chance enemies

Unlike common enemies, enemies with a low chance per tile (under 10%) become more likely the more tiles you place. If you want a specific rare enemy or its drops, it is worth covering all 256 tiles of a chunk (16×16) with that tile.

• Within one chunk: more tiles means a higher chance per spawn event (table below).
• If you have room: only 1 spawns per chunk per event, so for the same number of tiles, splitting them across chunks gives more spawns. For example, 128 tiles in each of 2 chunks beats 256 tiles in one chunk (second column from the right).
• Enemies with a 0.2% chance (Geobots, Void Cavelings, etc.) only appear about 40% of the time per event even with 256 tiles. Plan on using several chunks.

Enemy (tile, per tile)	13 tiles	64 tiles	128 tiles	256 tiles whole chunk	128 tiles × 2 chunks	Notable drops (per kill)
Geobot Miner Rust Pile, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Mechanical Part 18.1%, Relucite Ore 9.2%, Relucite Key 0.94%
Geobot Patroller Rust Pile, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Mechanical Part 41%, Flamethrower 2%, Relucite Key 0.65%
Void Caveling Muddled Moss, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Black Charm Necklace 7.8%, Oblivion Fragment 65.3%, Void Club 7%
Void Caveling Brute Muddled Moss, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Black Charm Necklace 7.8%, Oblivion Fragment 65.3%, Void Club 7%
Void Caveling Shaman Muddled Moss, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Black Charm Necklace 7.8%, Oblivion Fragment 65.3%, Void Club 7%
Void Larva Cocoon Muddled Moss, 0.2%	2.6%	12%	22.6%	40.1%	0.45	Oblivion Fragment 21.4%
Caveling Brute Stone Moss, 0.5%	6.3%	27.4%	47.4%	72.3%	0.95	Crystal Skull Shard 18.4%, Ancient Gemstone 9.5%, Mechanical Part 9.5%
Core Sentry Urban Moss, 0.5%	6.3%	27.4%	47.4%	72.3%	0.95	Core Sentry Figurine 0.43%, Sentry Helm 0.11%, Octarine Ore 14.3%
Shrooman Brute Fungal Soil, 0.5%	6.3%	27.4%	47.4%	72.3%	0.95	Ancient Gemstone 10.3%
Mold Tentacle Mold Block, 0.5%	6.3%	27.4%	47.4%	72.3%	0.95	Mold Vein Necklace 0.68%, Mold Ring 0.68%, Vicious Ring 0.68%
Red Slime Ground Slime, 1%	12.2%	47.4%	72.4%	92.4%	1.45	Crown Summoning Idol 0.22%, Ancient Gemstone 1.1%
Big Larva Chrysalis, 1%	12.2%	47.4%	72.4%	92.4%	1.45	Shiny Larva Meat 0.5%, Grub Egg Necklace 0.08%
Cocoon Chrysalis, 1%	12.2%	47.4%	72.4%	92.4%	1.45	—
Caveling Shaman Stone Moss, 1%	12.2%	47.4%	72.4%	92.4%	1.45	Shaman Skull 2%, Crystal Skull Shard 19.5%, Ancient Gemstone 4.9%
Geobot Scourer Rust Pile, 1%	12.2%	47.4%	72.4%	92.4%	1.45	Mechanical Part 18.4%
Wingling Ravine Coral, 3%	32.7%	85.8%	98%	100%	1.96	Ancient Gemstone 5.3%
Void Larva Muddled Moss, 4%	41.2%	92.7%	99.5%	100%	1.99	Black Charm Necklace 0.99%, Oblivion Fragment 9.9%
Orbital Turret Crystal Crust, 5%	48.7%	96.2%	99.9%	100%	2.00	Arcane Monk Blindfold 2.4%, Arcane Monk Cloak 2.4%, Arcane Monk Leggings 2.4%

The tile-count columns are the chance that at least one spawns in one chunk per spawn event. "128 tiles × 2 chunks" is the expected number spawned across both chunks per event. All values assume none of the same enemy is left over from earlier events. Drops show up to 3 items of Rare or higher, as the chance per kill.

How spawn tile chances work

At each spawn event, every spawn tile makes a "roll". Each enemy has its own chance, and each enemy is rolled separately.

• Spawn chunk (16×16): tiles are counted per 16×16 chunk, split at every multiple of 16 in world coordinates (coordinates 0-15 are the first chunk, 16-31 the second…). The corner of your room isn't necessarily a chunk corner.
• Chance per tile: each tile spawns the enemy at this chance.
• Minimum tiles: a chunk needs at least this many of the tile (with fewer, nothing spawns).
• Per-event limit: the most that can spawn in one chunk per event. Each enemy has its own limit.
• Density limit: the most of that enemy that can be in the chunk: "density value × number of tiles", rounded up. Enemies of the same type already there count toward it.
• Reduction from leftover enemies: if the same enemy is already present, the chance drops (chance × (1 − decay)^{number present}). For most enemies each one present multiplies it by 0.2; Void Larvae by 0.3 and mushrooms by 0.9. Infected Cavelings and Mold Tentacles have no reduction.
• No-spawn zones: nothing spawns within 6 tiles of a player or within 12 tiles of the world center (0, 0).
• Interval: chunks are checked in turn, and one full cycle takes about 15 minutes (15-22 minutes in practice).

Chance, decay, limit and minimum-tile values are from the game's config files (Conf folder Spawn/Respawn, version 1.3.0.6). Chunk size, no-spawn zones and the interval are from the Core Keeper Wiki (Fandom) pages "Spawning tiles" and "Guides/Mob farming" (CC BY-SA 3.0); we could not confirm them in the game files.

Spawn chances by tile (spawn rate per enemy and items you get)

For each tile: the chance of each enemy, and the items you get from killing them (chance per tile). Open "Items from kills" to see the full list.

Ground Slime spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Orange Slime	30%	1	+0.15 per tile	6
Red Slime	1%	1	+0.05 per tile	6

Ground Poison Slime spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Purple Slime	30%	1	+0.15 per tile	6

Ground Slippery Slime spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Blue Slime	30%	1	+0.15 per tile	6

Ground Magma Slime spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Lava Slime	30%	1	+0.15 per tile	6
Lava Butterfly	10%	1	+0.08 per tile	6

Chrysalis spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Larva	30%	1	+0.15 per tile	6
Big Larva	1%	1	+0.05 per tile	6
Cocoon	1%	1	+0.05 per tile	6

Stone Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Caveling	30%	1	+0.15 per tile	6
Caveling Shaman	1%	1	+0.05 per tile	6
Caveling Brute	0.5%	1	+0.02 per tile	6

Clay Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Caveling Skirmisher	30%	1	+0.15 per tile	6
Caveling Spearman	30%	1	+0.15 per tile	6

Lush Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Caveling Gardener	30%	1	+0.15 per tile	6
Caveling Hunter	30%	1	+0.15 per tile	6

Urban Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Caveling Scholar	30%	1	+0.15 per tile	6
Core Sentry	0.5%	1	+0.02 per tile	6

Valley Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Caveling Assassin	30%	1	+0.15 per tile	6

Crystal Crust spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Mimite	30%	1	+0.15 per tile	6
Orbital Turret	5%	1	+0.05 per tile	6

Fungal Soil spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Mushroom	20%	2	+0.6 per tile	4
Shrooman	10%	1	+0.08 per tile	6
Shrooman Brute	0.5%	1	+0.02 per tile	6

Mossy Soil spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Moorshroom	20%	2	+0.6 per tile	4

Rust Pile spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Geobot Scourer	1%	1	+0.1 per tile	6
Geobot Miner	0.2%	1	+0.05 per tile	6
Geobot Patroller	0.2%	1	+0.05 per tile	6

Muddled Moss spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Glowing Mushroom	20%	2	+0.6 per tile	4
Void Larva	4%	1	+0.1 per tile	6
Void Caveling	0.2%	1	+0.05 per tile	6
Void Caveling Brute	0.2%	1	+0.05 per tile	6
Void Caveling Shaman	0.2%	1	+0.05 per tile	6
Void Larva Cocoon	0.2%	1	+0.05 per tile	6

Mold Block spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Infected Caveling	10%	4	+0.2 per tile	4
Mold Tentacle	0.5%	1	+0.05 per tile	6

Ravine Coral spawn chances

Spawns	Chance per tile	Per-event limit	Max in chunk	Min. tiles
Wingling	3%	1	+0.15 per tile	6

The chance in "Items from kills" is the chance of getting that item per tile per spawn event (= chance that enemy spawns from one tile × chance it drops at least one when killed, summed over the enemies from this tile). For mushrooms and similar, it is the amount you harvest. Per-event limits and the reduction from leftover enemies are not included. Hover over a name to see which enemies drop it.

How many spawn tiles are most efficient? (one 16×16 chunk)

The expected number spawned per spawn event when you place n tiles (each tile rolls, capped at the per-event limit). For enemies capped at 1, this equals the chance of at least one spawning.

How many Ground Slime to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Orange Slime	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Red Slime	5.9%	8.6%	14.9%	27.5%	47.4%	72.4%	92.4%	Not reached even at 256

How many Ground Poison Slime to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Purple Slime	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles

How many Ground Slippery Slime to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Blue Slime	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles

How many Ground Magma Slime to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Lava Slime	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Lava Butterfly	46.9%	61.3%	81.5%	96.6%	99.9%	100%	100%	29 tiles

How many Chrysalis to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Larva	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Big Larva	5.9%	8.6%	14.9%	27.5%	47.4%	72.4%	92.4%	Not reached even at 256
Cocoon	5.9%	8.6%	14.9%	27.5%	47.4%	72.4%	92.4%	Not reached even at 256

How many Stone Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Caveling	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Caveling Shaman	5.9%	8.6%	14.9%	27.5%	47.4%	72.4%	92.4%	Not reached even at 256
Caveling Brute	3%	4.4%	7.7%	14.8%	27.4%	47.4%	72.3%	Not reached even at 256

How many Clay Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Caveling Skirmisher	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Caveling Spearman	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles

How many Lush Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Caveling Gardener	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Caveling Hunter	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles

How many Urban Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Caveling Scholar	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Core Sentry	3%	4.4%	7.7%	14.8%	27.4%	47.4%	72.3%	Not reached even at 256

How many Valley Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Caveling Assassin	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles

How many Crystal Crust to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Mimite	88.2%	96%	99.7%	100%	100%	100%	100%	9 tiles
Orbital Turret	26.5%	37%	56%	80.6%	96.2%	99.9%	100%	59 tiles

How many Fungal Soil to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Mushroom	1.08	1.43	1.83	1.99	2.00	2.00	2.00	19 tiles
Shrooman	46.9%	61.3%	81.5%	96.6%	99.9%	100%	100%	29 tiles
Shrooman Brute	3%	4.4%	7.7%	14.8%	27.4%	47.4%	72.3%	Not reached even at 256

How many Mossy Soil to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Moorshroom	1.08	1.43	1.83	1.99	2.00	2.00	2.00	19 tiles

How many Rust Pile to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Geobot Scourer	5.9%	8.6%	14.9%	27.5%	47.4%	72.4%	92.4%	Not reached even at 256
Geobot Miner	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256
Geobot Patroller	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256

How many Muddled Moss to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Glowing Mushroom	1.08	1.43	1.83	1.99	2.00	2.00	2.00	19 tiles
Void Larva	21.7%	30.7%	48%	72.9%	92.7%	99.5%	100%	74 tiles
Void Caveling	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256
Void Caveling Brute	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256
Void Caveling Shaman	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256
Void Larva Cocoon	1.2%	1.8%	3.2%	6.2%	12%	22.6%	40.1%	Not reached even at 256

How many Mold Block to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Infected Caveling	0.58	0.84	1.58	2.84	3.84	4.00	4.00	61 tiles
Mold Tentacle	3%	4.4%	7.7%	14.8%	27.4%	47.4%	72.3%	Not reached even at 256

How many Ravine Coral to place

Spawns	6 tiles	9 tiles	16 tiles	32 tiles	64 tiles	128 tiles	256 tiles	Tiles to reach ~limit (95%)
Wingling	16.7%	24%	38.6%	62.3%	85.8%	98%	100%	99 tiles

Summary: efficient spawn tile layouts for farms

• For common enemies (30% chance, limit 1): about 9 tiles gets spawns per chunk close to the limit (about 96%). Rather than one big area, place small patches in separate chunks to get more spawns.
• For low-chance enemies (Brutes, Shamans, etc.): their chance is 0.5-1%, so more tiles means more spawns. Even with 256 tiles the chance per event is only a few tenths up to about 70% (table above).
• Mushrooms (limit 2, 20% chance): a few tiles (4 or more) reach close to the limit of 2 per event.
• For any enemy: below the minimum tile count (usually 6), nothing spawns at all.

Each enemy is rolled separately, assuming none are left over from earlier events. Each leftover enemy lowers the chance (×0.2 for most enemies).

Tips for building a mob farm

1. Decide your target enemy or resource: pick its spawn tile from the list. Check what the enemy drops (on its enemy page) first.
2. Think in 16×16 chunks: minimum tiles are counted per chunk. If you split a 6-tile patch 3 and 3 across a chunk border, neither chunk has enough.
3. Meet the minimum in every chunk: for a 30% enemy, 6 tiles give about 88% chance of at least one, and 13 tiles give over 99%. One full row (16 tiles) gives about 99.7%.
4. Wait more than 6 tiles away from the tiles: too close and nothing spawns. But stay near the farm so its chunk doesn't stop being active.
5. Keep a path clear for collecting: build one small chunk first, check it works, then copy the layout to other chunks.

More spawns, or rare enemies?

• More common enemies: once one chunk reaches its per-event limit, build the same tiles in another chunk. Adding tiles to the same chunk doesn't raise the limit. For example, 256 tiles of a 30% enemy in one chunk still gives at most 1 per event, but 16 tiles in each of 16 chunks gives 16 chances.
• Rare enemies: add more of that tile. For example, the Caveling Brute has about a 6.3% chance with 13 tiles of Stone Moss, but about 72% with 256 tiles.
• Many kinds of enemies: mix different tiles in one chunk and meet each one's minimum. For example, 13 tiles each of Chrysalis, Clay Moss, Ground Slime, Ground Poison Slime (52 in total) leaves 204 tiles for paths and traps. Enemies won't necessarily kill each other, so build a way to contain them first.
• Mushrooms (Mushroom, Glowing Mushroom, Moorshroom): harvest them regularly. If you don't, new ones become less likely to grow.

Clear leftover enemies (they lower the spawn chance)

Leftover enemies of the same type lower the next spawn chance and fill up the density limit. Kill them with spike traps or carry them to a collection point with conveyor belts so none are left. Expanding the tiles won't increase spawns if collection stops.

Mechanics from the Core Keeper Wiki (Fandom) page "Guides/Mob farming" (CC BY-SA 3.0), for chunk borders, the 6-tile no-spawn range and what blocks spawns (not confirmed in the game files); tile counts and chances are from the game files.

Spawn tiles and mob farms: FAQ

Q. Why don't enemies spawn in my mob farm?

Check the following: does the same 16×16 chunk have the minimum tile count (usually 6)? Are there torches, blocks or furniture on the tiles? Is a player within 6 tiles? Are enemies of the same type left over from before? Spawn events are 15-22 minutes apart, so wait one full cycle before deciding (see the no-spawn checklist).

Q. How many spawn tiles should I place?

For common enemies (30% chance), 13 tiles per chunk gives 99%. To get more, build the same thing in other chunks. For rare enemies, place more of that tile. The calculator works out tile counts that spawn your chosen enemies in balance.

Q. Can I mix different spawn tiles in one chunk?

Yes. Each enemy has its own limit, so as long as each tile meets its minimum, enemies spawn from all of them.

Q. Does lighting the area stop spawns?

Light level doesn't matter. However, a torch placed on a tile stops spawns from that tile. Put lights off the tiles.

Q. Can I put spike traps or conveyor belts on spawn tiles?

Yes. These two don't block spawns when placed on top.