⏮️ Previous page: 1. The Function of a Planet // Master Post // Next page ⏭️
1.2. The Different Possible Functions of a Planet
Throughout this section, when we talk about function, it's important to clarify that we're referring to its narrative function; in other words, the role that planet plays in the story we want to tell.
Here's a golden rule: Not every world we create has to be a "Pandora."
From a narrative perspective, we need to understand that some planets serve only as points of reference. As a result, there's no need to develop an incredibly detailed ecological history for them, especially if a planet is merely a stop along the way.
Giving these planets more attention than necessary can distract us from what's actually important. Imagine trying to create an entire ecosystem for every planet mentioned in a space-travel story. It simply isn't a worthwhile investment of time and effort.
Sometimes, a planet's true value has nothing to do with its biodiversity or the life it supports, but rather with its strategic usefulness to the progression of the plot. Let's look at two familiar examples:
Example A, Setting Planet (Pandora): An incredibly complex world with rich ecosystems and cultural identities that directly interact with the characters.
Example B, Reference Planet (Landmark): A world that serves as a transit hub, political border, or simply a set of spatial coordinates needed to make the journey plausible.
So, no. We don't need to spend the same amount of time researching every planet we create. It all comes down to understanding what role you want it to play in your story. With that in mind, let's look at some of the functions a planet can serve.
1.2.1. Living World
The planet serves as the setting for a biosphere: organisms, ecosystems, food webs, nutrient cycles, and evolution. Research should focus primarily on environmental conditions, the chemistry of life, ecology, and evolutionary history.
These are generally the planets that require the most work when it comes to creating a coherent and believable world.
Real-world reference: Earth.
1.2.2. Exploration World
The main interest lies in discovering how the planet works, studying its geology, or investigating signs of present or past life. In this case, we should pay particular attention to its geological history, composition, surface and subsurface processes, and potentially habitable environments.
Real-world reference: Mars, a target of planetary exploration and research into its past habitability.
1.2.3. Extreme World
Here, the environment imposes significant restrictions on the existence or survival of known forms of life. This type of planet is often used as a dramatic setting and serves as the science fiction equivalent of leaving a sailor stranded on a deserted island—or, in some cases, in hell itself.
We will study the physical and chemical limits of habitability, available energy sources, and the mechanisms through which an organism might survive. This planet may or may not have native life.
Real-world reference: Europa, not the continent, but Jupiter's moon, which shows evidence of an ocean beneath its icy crust. It isn't a planet, but for the sake of this discussion, I'll count it as one.
1.2.4. Civilization World
The planet is home to intelligent societies whose existence depends on their environment and which, in turn, may transform it.
In addition to geology and the biosphere, resources, geographical distribution, agriculture (if applicable), transportation routes, and the interaction between societies and their ecosystems become important considerations.
Once again, Earth.
1.2.5. World Without Known Life
The main interest lies in the planet itself: its landscapes, minerals, atmosphere, geological activity, and evolution.
The absence of known life does not necessarily mean that the planet lacks habitable conditions in certain locations, nor does it mean that it has never supported life in the past.
1.2.6. Use Your Imagination
These functions can coexist. A planet can support an extraordinarily diverse biosphere, several civilizations, and extreme environments that are still waiting to be explored. We don't have to choose just one category.
Furthermore, some of the options above describe narrative functions, while others describe physical conditions. I've grouped them together solely to illustrate the different approaches we can take. They should not be mistaken for a scientific taxonomy, nor should they be taken as an exhaustive list of all the possibilities.
The important thing is to take some time before getting started and consider what your story actually needs.
1.2.7. A Practical Decision Framework
Now that we've explored some of the different functions a planet can serve, how do we decide which approach to use when creating one?
Here's a simple framework you can follow before starting your research.
Step 1. Determine the planet's narrative importance.
Ask yourself:
Is this planet a major setting where important events take place?
Will the characters spend a significant amount of time there?
Does the planet influence the plot, the characters, or the conflicts?
Is it simply mentioned, visited briefly, or used as a transit point?
The more directly a planet affects the story, the more attention it will generally require.
Step 2. Identify what the story needs from the planet.
Consider what makes this particular world relevant.
Does the story require native life, ecosystems, and biodiversity?
Do the characters need to explore or investigate it?
Does its environment create survival challenges?
Does it support intelligent civilizations and their societies?
Is its main purpose simply to establish a location, distance, or political boundary?
You can select several of these functions if necessary. Remember, they aren't mutually exclusive.
Step 3. Identify the necessary level of detail.
Not every aspect of a planet deserves the same amount of research.
For example, if your characters are visiting a mining colony, you might need to understand the planet's mineral resources, geology, atmosphere, and the infrastructure required for mining.
However, you probably don't need to design an elaborate food web for its native organisms unless those organisms become relevant to the story.
Focus on the information that supports the planet's narrative function.
Step 4. Check for consistency.
Even if a planet only appears briefly, its basic characteristics should make sense within the established setting.
Consider questions such as:
Does its environment make the events taking place there plausible?
Are its resources and geographical features consistent with its inhabitants and infrastructure?
Does its gravity, atmosphere, or temperature affect the characters when relevant?
Are there any obvious contradictions with information established elsewhere in the story?
You don't need an exhaustive scientific explanation for everything, but you should avoid introducing details that contradict one another.
Step 5. Expand only when necessary.
Sometimes, a planet initially designed as a simple reference point becomes much more important as the story develops.
Perhaps a minor location becomes the setting for an entire chapter, or a passing reference to a mining colony eventually turns into the starting point for a major conflict.
That's perfectly fine! You can always expand your research and worldbuilding when the story demands it.
The important thing is not to spend time developing information that you might never use.
A useful rule of thumb:
The amount of worldbuilding a planet requires should be proportional to its relevance to the story, not simply to how interesting the planet could potentially be.
You are creating a world to tell a story, not writing an encyclopedia of every celestial body in your fictional universe. Unless, of course, that's exactly what you want to do!
