|This article is about the current version of DF.|
A Shell is a hard external covering used by certain creatures for defense. Shells can be obtained by capturing or killing shell-bearing creatures and processing them at a fishery (or in rare cases, a butcher's shop). Examples of shelled vermin critters are turtles, oysters and mussels; larger shelled creatures include giant snails and some forgotten beasts. Shells currently cannot be acquired via trading -- turtles, crustaceans and shellfish purchased from traders have already been processed and had their shells removed.
Shells can be stored in a refuse stockpile, but stored shells may disappear due to vermin such as rats. Shells can be used for a few types of armor, crafts, and decorations at a craftsdwarf's workshop using the bone carver skill. Shells may occasionally be requested by a moody dwarf, so it is best to keep a few on hand just in case.
|MOD||This section includes mods. The content is not part of normal DF as released. Changing game files can sometimes cause unexpected results, and should always be done with care and caution.|
In previous versions, shells were frequently requested by moody dwarves, and difficult if not impossible to obtain. As of the current version, only dwarves with a preference for shells will demand them for artifacts. Shells are still hard to come by, though, so players occasionally mod the game to make sure their fortress will have shells available.
 Adding Shells to Existing Creatures
The combination of the common requirement for shells during Strange Moods, the bug that causes shell-producing fish to be unavailable in many maps, the inability to trade for shells may lead to unresolvable Strange Moods. It is possible to modify the raws to allow other creatures to produce shells if the player is so inclined:
- In raw/objects/creature_domestic.txt, find "[CREATURE:COW]"
- Alter the [BODY] section to include ":SHELL" i.e., [BODY:QUADRUPED_HOOF:TAIL:2EYES:SHELL:BRAIN...]
- Add the [USE_MATERIAL_TEMPLATE:SHELL:SHELL_TEMPLATE] tag to the [BODY_DETAIL_PLAN:STANDARD_MATERIALS] section
- Add the [USE_TISSUE_TEMPLATE:SHELL:SHELL_TEMPLATE] tag to the [BODY_DETAIL_PLAN:STANDARD_TISSUES] section
- Add the [BODY_DETAIL_PLAN:SHELL_POSITIONS] tag to the creature
- If you wish to apply this change to a game in progress, remember to also alter the copy of creature_domestic.txt contained in your saves folder, as each game has its own copies of the raws.
Slaughtering a cow should now produce a "Stray Cow shell" usable by dwarves stuck in strange moods. Pay attention, that editing creature after creating world may cause later crashes when changing game's version. In fact, after porting the save to the modified version, the game will crash every time your dwarves try picking up the skeleton that previously had shell. It's strongly recommended to use the second way, as it doesn't add any new body part to creatures, but only add new way of using already existing body part, which is much less crash provoking.
 Enabling Other Materials to Be Used in Moods
If you don't want to add shells to existing creatures, you can enable other materials, like hooves or ivory to be used in strange moods instead of shells. The only effect is that the materials will be available for moods, you won't be able to e.g. make shell crafts of them.
- In raw/objects/material_template_default.txt look up the material you want to enable, for example [MATERIAL_TEMPLATE:HOOF_TEMPLATE]
- Add the [SHELL] to the material
- If you wish to apply this change to a game in progress, remember to also alter the copy of material_template_default.txt contained in your saves folder. The change won't affect body parts that are already lying around, but will affect newly created body parts from butchered creatures.