Assembling a Skeleton (Guide)

Mid PoSI Content and Onwards

Assembling a Skeleton Summary
Limited-Length Conversion Activity
Setup				Progress				End
1 A				1+ A				2 A
Progress Details			Add Skulls, Limbs, and Tails until your skeleton is complete.
Items Inputs/Outputs Inputs Category:Osteology Outputs Bone Fragments Unearthly Fossil Thirsty Bombazine Scrap Preserved Surface Blooms Rumour of the Upper River Incisive Observation Crate of Incorruptible Biscuits Bessemer Steel Ingot Unprovenanced Artefact Hinterland Scrip Basket of Rubbery Pies Nightsoil of the Bazaar Ambiguous Eolith Memory of Light Tailfeather Brilliant as Flame Bottle of Morelways 1872 Royal-Blue Feather Memory of Distant Shores Final Breath Carved Ball of Stygian Ivory Nodule of Warm Amber Knob of Scintillack An Identity Uncovered! Leviathan Frame Piece of Rostygold Vital Intelligence Fistful of Surface Currency Vienna Opening Volume of Collated Research Whisper-Satin Scrap Ostentatious Diamond Slim Volume of Bazaarine Poetry Solacefruit Assortment of Khaganian Coinage Compromising Document
Raw EPA			7.92*			Raw SPA			15.83*

A guide on how to Assemble a Skeleton in The Bone Market, both as an introduction to skeleton-building and a reference for those already familiar. A slower start is available as a step-by-step tutorial.

Here's a quick list of the most used cheat sheets from this guide:

• List of Buyers
• Skeleton Types
• List of Bones
• List of Bone Sources
• List of Recipes

If you're unsure what can you build with the bones that you have on hand, test your skeletons in the Bone Market Calculator. You may also generate optimal designs based on specific world qualities and other criteria using the Bone Market Solver.

Why Should I Make a Skeleton?

There are two main reasons to construct a skeleton: To obtain the specific items available in the Bone Market, or to assemble home comforts. There are a variety of buyers, who each pay out in different items. A table of these buyers is also included in this guide.

Assembling skeletons is usually not more profitable than the best echo grinds, except for the exponential rewards from some buyers. Because these exponential rewards can be so profitable, you are limited in how often you can sell valuable skeletons to these buyers by way of Bone Market Exhaustion, which is reduced each week by Time, the Healer. For all other skeletons, the payout you can get per bone used is usually on par with the material resources required to obtain it, with some extra action overhead. Skeletons can be thought of as a way to convert existing resources into specific items. Skeletons can be the most efficient way to obtain specific resources, especially those which are associated with the Railroad content or required for making other skeletons.

Mechanics

Before you Start

First you will need to unlock access to The Bone Market. This is done with an early research assignment in the University Laboratory, where the Dean asks you to investigate a bone. After you do that, you will be able to enter the Market from the Dept. of Menace Eradication.

You have to Invest in a Stall of your Own before you can assemble a skeleton. This is a one-time expense. More expensive stalls allow you to use larger ribcages, and lower the amount of Respectable needed for Present Yourself as a Respectable Citizen which allows you to lower your Suspicion. These are the three tiers available, and their cost:

• A small stall for 20 x Bottle of Broken Giant 1844.
• A decent stall for one Bottle of Fourth City Airag: Year of the Tortoise.
• A handsome dais at the end of the room for one Bottle of Fourth City Airag: Year of the Tortoise and three Comprehensive Bribes. (Having done one specific ending of either Ambition: Bag a Legend! or Ambition: Heart's Desire! lets you get this for free.)

You can always upgrade to a larger stall, but you do not get any discount for already having a stall. Therefore you save resources by buying the most expensive stall first, if you can afford it.

Finding Bones

To assemble a skeleton, you need bones (or bone-like objects). When you unlock the Bone Market, you also unlock many previously-hidden opportunities to collect Osteology items around Fallen London.

For more information on this, look through the List of Bone Sources →

Assembly

The first step is to pick a Torso to use as a basis for your Skeleton. This determines how many bones your skeleton has room for, as well as which "types" you can declare at the end. Second, you add Skulls. Third, after you fill all of the neck slots, you add the rest of the bones: limbs, tails, and other modifications. Finally, you complete your Skeleton by declaring what "type" it is. You may then sell your completed skeleton.

You can leave your stall freely and resume your Skeleton later without losing progress. This is useful for obtaining bones you might be missing. You can only work on one Skeleton at a time, and there is a penalty for stopping and starting over.

For a more complicated skeletons (i.e. requiring additional limbs) you should always make sure you have enough Bone Fragments and Nodule of Warm Amber before you begin a Skeleton, because the best source of those items are selling other Skeletons.

The "type" of your Skeleton depends on whether you chose limbs according to some coherent, taxonomically plausible concept of anatomy or not. The "types" match anatomies to bone categories. For example, if your Skeleton has one Skull and four Arms, then you can call it an Ape, but if it has two Legs and two Wings then you can call it a Bird. The penalty for not following a body plan is that your Skeleton is a Chimera, increasing its Self-Evident Implausibility, and there is a bonus for following the "type" that is currently in fashion. A few uses for Skeletons require specific "types," but most buyers are not particular beyond the aforementioned bonus/penalty.

Skeleton Attributes

Every bone you add to a skeleton increases the Approximate Value of Your Skeleton in Pennies. Most bones also affect one or two other Qualities related to Skeletons, listed below:

• Skeleton: Amalgamy (associated with Bizarre)
  • Can be reduced using Lithification Liquid
• Skeleton: Antiquity (associated with Respectable)
  • Can be reduced using a Scrimshander Carving Knife
• Skeleton: Menace (associated with Dreaded)
  • Can be reduced using Patent Osteological Sand and Wax
• Skeleton: Support for a Counter-church Theology (associated with the Bohemian Sculptress)
• Skeleton: Self-Evident Implausibility (a penalty which makes the skeleton more difficult to sell)

These qualities have three uses when selling Skeletons in the Bone Market:

• Every buyer pays out a Primary Reward, in an amount proportional to the Approximate Value of Your Skeleton in Pennies
• Some buyers require your Skeleton to have (or not have) certain Skeleton Attributes
• Most buyers pay out a Secondary Reward, in proportion to the value of your Skeleton Attributes

Selling a Skeleton to a buyer is a Shadowy challenge, with the difficulty proportional to Implausibility. Failure accrues Suspicion, but there is otherwise no penalty for either gaining Implausibility or failing to make a sale. Implausibility can be lowered by spending Revisionist Historical Narratives.

Bone Market Exhaustion

Because some buyers secondary reward scaling allow for incredibly profitable skeletons, Bone Market Exhaustion was implemented to limit grinding this. Building up too much of this quality (4+) locks you from being able to sell skeletons to these buyers, though their other trades will still be available. The things that increase Exhaustion are:

• Selling skeletons to buyers with secondary rewards that scale multiplicatively. For every 50 of profits from the secondary, multiplicative reward, you get one Exhaustion.
• Using Custom-Engraved Skulls: These skulls can be sent to you during the FEAST OF THE ROSE, costing 20 for the sender. With their exceptionally high Penny Value of 10 000, adding one of these skulls gives two Exhaustion.

World Qualities

Introduced on 25 May 2021, World Qualities are shared across the entire playerbase and change on Tuesday, at 11AM UTC every week. For the Bone Market these affect three things:

• Preferred Quality: Every week a different skeleton quality will be especially wanted, and all calculations involving that quality will give more than usual, without raising the exhaustion gain.
• Preferred Skeleton Type: Every week a different skeleton type will be the rage. Declaring a skeleton of that type will raise its Approximate Value of Your Skeleton in Pennies by 10% (or 15% for harder types) when you declare it.
• Unique Buyer: Every week a normally not available buyer visits, which will have a special interest something. These work as usual, but are not normally available. These sellers usually give a good price for special skeletons, but not always.

Declaring Skeletons

In practice, it is good to keep in mind which type of creature that you will want to declare at the end while you build the skeleton. Realising that you have made a mistake that leads to a Chimera is unpleasant.

Now, for some important basics about declaring skeletons:

• Most declarations require exact numbers for skulls and limb types, except as noted below.
  • Birds are valid with any number of Skeleton: Skulls, including zero.
  • Fish require at least two Skeleton: Fins, but have no upper bound - the only creature to which more joints can be added indefinitely.
  • While Amphibians require exactly four Skeleton: Legs, Reptiles will accept a range of legs between zero and four.
  • While Insects require exactly six legs, they accept a range of wings between zero and four.
• Skeletons built from any of the human ribcages can only be declared as Human or Ape (or Chimera). Skeletons built from non-human ribcages cannot be declared Human/Ape but can be declared as any other type. The Thorned Ribcage is unique in that it can be used for any type of skeleton.
• Humans, Apes, Monkeys, Reptiles, Curators, and Chimeras are the only skeleton types that have Skeleton: Arms.
• The Carved Ball of Stygian Ivory uses up a Neck Slot but does not increase the count of Skeleton: Skulls. Use these to address a mismatch between the necks available on your torso and the skulls expected for your skeleton type.
• Likewise, Skeleton: Tentacles do not count as any type of limb when declaring a skeleton, and can be used to address mismatches in limb slots.
• You can increase the number of limb slots, but only in batches of exactly four. The cost increases steeply, and it does not directly add skeleton value.
• Spiders don't have heads (the brain is contained in the cephalothorax) but insects do.
• Chimeras and Curators are the only skeleton types that cannot be fashionable, meaning their value cannot be increased by the weekly Zoomania bonus.

A few common/interesting skeleton recipes can be found in the recipe part of this Guide.

Skeleton Type requirements

A comprehensive list of Skeleton Types, the part requirements and restrictions necessary to declare such a skeleton, and any additional items or qualities required for the declaration:

Skeleton Type Requirements

Animal	Torso	Skulls	Arms	Legs	Wings	Fins	Tails	Tentacles	Mania Bonus	Other
Chimera	Any	Any	Any	Any	Any	Any	Any	Any	N/A	N/A
Humanoid	10-20	1	2	2	0	0	0	Any	10%	N/A
Ape	10-20	1	4	0	0	0	0	Any	10%	N/A
Monkey	10-20	1	4	0	0	0	1	Any	10%	N/A
Bird	20+	Any	0	2	2	0	0-1	Any	10%	Study of Avian Anatomies
Amphibian	20+	1	0	4	0	0	0	Any	10%	Account of Frogs etc.
Reptile	20+	1	0	0-4	0	0	1	Any	10%	Account of Frogs etc.
			2	2
Fish	20+	1	0	0	0	2+	0-1	Any	15%	Anatomies of Aquatic Life-forms
Insect	20+	1	0	6	0-4	0	0	Any	15%	Survey of Arachnids and Insects
Spider	20+	0	0	8	0	0	0-1	Any	15%	Survey of Arachnids and Insects
Curator	Any	1	2	2	2	0	0	Any	N/A	Connected: The Masters 3

 

Selling a Skeleton

Making a sale requires passing a Shadowy check, which is more difficult with higher Implausibility. A failure will gain Suspicion and waste the action, but will not affect your Skeleton. Additionally, some buyers will only buy Skeletons having (or missing) specific properties.

It is usually not a problem to have a couple levels of Implausibility. Some buyers are more difficult to convince than others, and having too high Implausibility can make it severely difficult to sell the skeleton. Having zero guarantees a sale, as the probability of success is set at 100%.

Buyers give a primary reward proportional to the Approximate Value of Your Skeleton in Pennies. When the reward item can be sold to the Bazaar, the sale value will match your Skeleton's value as closely as possible, usually with a small bonus amount. Many reward items cannot be sold to the Bazaar, but have a presumed value instead, such as 10 pence per Nodule of Warm Amber or 50 pence per Hinterland Scrip. Some buyers also give a secondary reward, which varies depending on the specific properties of your Skeleton.

A cheat sheet for the buyers, what they want, and how they pay.

List of Buyers →

Strategy

The first thing you should do is decide what item you want to receive, and then pick which buyer you will be selling to. A table of buyers and what they pay is toward the bottom of this page. If multiple buyers pay in the same item, choose one specifically. Make sure you meet the BDR requirements of your buyer before you start.

Any particular buyer will only care about two Attributes at the most, in addition to the Approximate Value of Your Skeleton in Pennies. Whether you care about the buyer's Primary or Secondary reward will determine whether you should try to maximise the Approximate Value of Your Skeleton in Pennies and only get the bare-minimum of the other Attributes, or whether you should try to maximise the Attribute values. You can review the List of Bones to plan out how to optimise the Attributes you need.

You should decide ahead of time whether it's worthwhile to adhere to an existing body plan, or whether you should free yourself of the preconceived notions of the Great Chain. A Chimera gives more freedom to stick whatever bones you want to optimise your Skeleton Attributes, but makes your Skeleton harder to sell.

Managing Bone Market Exhaustion

It is important to note that for some buyers, the payout for Secondary Rewards is multiplicative. You will get more value by cramming unreasonable Attributes into a single Skeleton than by spreading those same values out over two plausible Skeletons. However, the buyers that pay out in this fashion are also subject to Bone Market Exhaustion to prevent abuse of the market.

When you sell a skeleton to a buyer with multiplicative scaling, you will accrue 1 Exhaustion per 50 (or 100) secondary rewards (primary rewards do not affect exhaustion). If your Exhaustion is 4 or higher, then those buyers are not available in the Bone Market. Bone Exhaustion is reduced by 4 levels per week by Time, the Healer, or can be reduced faster at great expense from A Public Lecture. Note that there is no upper bound for the amount of Exhaustion that a skeleton can generate, other than the resources needed to create it. Some players have exhausted their Bone Market for years by creating particularly extreme skeletons.

An ideal skeleton will have a secondary payout just under the threshold to accrue an additional point of Exhaustion. Player attempting to maximise the benefit of the Bone Market may wish to build a skeleton the day before Time, the Healer arrives which will raise their Exhaustion to 4.

Buyers that care about two attributes pay out in secondary rewards worth 2.50 each, so their threshold for each level of Bone Market Exhaustion is when the product of their two attributes is a multiple of 20. Note that if a secondary quality is in fashion, the payout increases but the exhaustion in unaffected. The increase in payout is proportional to the in-fashion attribute, favouring unbalanced mixes of attributes.

In the lists below, the number in parentheses is the count of secondary rewards when the higher-valued quality is in fashion.

Attribute mixes that produce 0 x Bone Market Exhaustion:

• 19 × 1 (28)
• 9 × 2 (22)
• 6 × 3 (21)
• 4 × 4 (18)

... that produce 1 x Bone Market Exhaustion:

• 13 × 3 (46)
• 9 × 4 (40)
• 6 × 6 (39)
• 7 × 5 (38)

... that produce 4 x Bone Market Exhaustion (for when Time, the Healer is near):

• 11 × 9 (104)
• 14 × 7 (105)
• 12 × 8 (102)
• 16 × 6 (104)
• 19 × 5 (104)

Top-end buyers that care about one attribute pay out in secondary rewards worth 0.50 each (Investment-Minded Ambassador being an exception, giving secondary rewards worth 2.50 instead), so their threshold for each level of Bone Market Exhaustion is when the square of their attribute is a multiple of 25. The maximum value of an attribute that will produce the target level of Exhaustion is listed in the table below. As above, fashions will increase the level of rewards without increasing Exhaustion, but in this case the reward count is exponential.

Exhaustion	Maximum Attribute Value	Regular Reward Value	Fashionable Reward Value
0	4	32	36.5
1	7	99	120
2	8	128	157.5
3	9	162	201.5
4	11	242	307.5

Beyond this point, every additional level of Skeleton quality will increase the Bone Exhaustion by at least one. There are no more "free" levels to obtain, so managing Bone Market Exhaustion is a matter of what length of lock-out you are willing to accept.

Notes on Specific Items

• The Headless Skeleton is the least valuable base, and its options are limited. Conversely though, it is simple and fast to complete. Unless you do something as silly as putting a Carved Ball of Stygian Ivory on it, you are guaranteed a humanoid declaration.
• The Human Ribcage may limit the creature type to just Humanoids and Apes, but it comes with no secondary qualities that may complicate getting buyers. Add the right skulls and limbs to get the buyer that you want.
• The Thorned Ribcage is the only base that can be used for any skeleton type. All other bases can only produce either primates or non-primates, but not both.
  • It does add Amalgamy and Menace, however, which means that you can't sell the resulting creature to every buyer, at least not without some hassle of removing them.
• The Leviathan Frame starts with two limb slots instead of four. Without adding more limbs to it, the only type of skeletons that could be made with a Leviathan is a Reptile, Fish or a Chimera.
• The Flourishing Ribcage starts with two heads and six limb slots. It is the only base skeleton with six limbs, making it simpler to make a Curator type skeleton. However, you will need to use a Carved Ball of Stygian Ivory on it to remove the second head.
• The Skeleton with Seven Necks lets you chuck a lot of skulls on it, but keep in mind that it already has 2 Legs.
• The Prismatic Frame is extremely valuable, but can only be a fish or a reptile without adding limbs.
• The Segmented Ribcage, by itself, can only be used to make a fish or a reptile. However, the ribcage can be added to a head or tail slot if the original ribcage is a Segmented Ribcage. Using it as a head will sacrifice the head slot, but add four limbs. Since the creature can't be used to make any creature with a head, the only thing the player can make is a bird or a spider. Using it as a tail will add two limbs, but preserve the tail slot, allowing additional segmented ribcages to be added, with sharply increasing costs.
• The Bright Brass Skull effectively lets you convert existing Echoes into Approximate Value of Your Skeleton in Pennies without spending Actions. This is as close as you can get to "buying" certain items.
• The Fossilised Forelimb is an Arm, despite the picture looking like a Wing. It costs 85 in the Hinterlands, and adds 2750 Skeleton Value, worth 55.
• The Withered Tentacle effectively reduce the number of limbs on your skeleton, because Skeleton: Tentacles is not counted by any existing Skeleton Type. This expands which Skeleton Types can be made from which torsos. The Withered Tentacle is also the only way to remove Antiquity without a seasonal reward item. Note that the Tentacle can be used as both a limb and a tail.
• If you add a tail, and then Remove the tail from your Animal, your Skeleton retains any Attributes that the tail added.
• The option to Add four more joints to your skeleton spends Warm Amber in proportion to the square of the number of joints your skeleton already has, and does not increase the Approximate Value of Your Skeleton in Pennies. This should only be done if you have a specific use in mind for the extra limbs.

Bones and their attributes

A comprehensive table of every bone in the game and its attributes:

List of Bones →

Bone Market Calculator

You can test the skeleton you're planning to build with the Bone Market Calculator. Copy this spreadsheet to your Google Drive, list the bones you want to use and see what kind of reward you can get from buyers.

Some Skeleton Recipes

A list of commonly used skeleton recipes. It will be updated as more skeleton parts are implemented.

List of Recipes →