Crucible

Crucible is the high-pressure planet with a crafting chain built around creating metallic hydrogen. It is designed to be as "vanilla-like" a planet as possible while still be different enough to be a fun and interesting challenge.

The Planet

Crucible is a large, dense rocky world with crushing gravity and atmospheric pressure. Its close proximity to the sun results in a scarcity of asteroids in orbit. Combined with its steep gravity well, Crucible can be a difficult planet to escape from—until you've mastered its high-pressure manufacturing.

Crucible is an "inner" planet that is intended to be visited before Aquilo. It can be visited first, and it is possible to bootstrap a Crucible base from nothing. It is moderately more difficult than Vulcanus, Gleba, or Fulgora; although there are no enemies, and no natural hazards, there are still likely to be some explosions...

Resources:

Skarn: a single ore that is your source of stone, iron, copper, and emery (an essential intermediate mineral).
Emulsion: a single fluid is your only source of both water and oil.
Coal: small deposits can be found here, but they are more difficult to exploit than on Nauvis.

The Industry

The main goals when designing Crucible's crafting chains were to:

Offer a vanilla-like experience that is unique, interesting and challenging.
Disrupt some assumptions/standards that most of us take for granted (such as the primacy of productivity modules).
Explore new ways to utilize Space Age mechanics (such as spoiling and space platform design).

Some ways this mod tries to achieve these goals are:

Most of Crucible's smelting recipes require an additional fluid ingredient.
Many recipes have a probabilistic output, which provide opportunities to utilize rigor modules.
Several intermediates in the crafting chain for metallic hydrogen spoil in interesting ways.

The ideal module setup for the machines crafting the high-pressure science pack will change as your factory grows, will differ across different factories, and usually does revolve around productivity modules. This is a dynamic that I've always wanted in Factorio, and I hope you find it interesting too!

Note: this mod was also designed along with the Rigor Module mod, and the production chains were built with rigor as an important component.

The Rewards

Through the process of mastering Crucible, you will unlock:

The kiln, a powerful new furnace powered by heat.
The pressure forge, a powerful new assembling machine with built-in +50% productivity and up to 10 module slots (depending on quality).
Metallic hydrogen, the holy grail of high-pressure physics.

Once Crucible and the high-pressure science pack are mastered, you can unlock:

New tools to drastically reduce the asteroid demands of your space platforms—without even blowing them up in the process (probably).
New infinite productivity technologies.
New personal equipment.
And more!

Compatibility

This mod is designed to play nicely with other planet mods. However, compatibility testing is still a work-in-progress. Please report any compatibility issues your find!

Note:

Adding this mod to an existing save should work, and does not require any extra setup.
By default, this mod makes a few changes to some Aquilo recipes and technologies.
This can be configured or disabled in the mod settings.
I generally recommend leaving these changes enabled, unless adding to an existing save that has already reached Aquilo or playing heavily-modded.

Known Issues/Limitations

This mod is still in relatively early development, and has had only limited testing (especially in multiplayer)!
Issues related to rigor modules can be found on that mod's page.

Credits

See CREDITS.md for more details.

Entity graphics: Hurricane
Icons: Malcolm Riley
Upscaling: snouz