Types of constructed worlds
four questions every world answers

The article’s examples mark the first distinction, and it is really a question of scale. A constructed world can be as small as a single place or as large as a whole universe; the famous settings just sit at different points on the same ruler.

• A continent. Tamriel, the setting of the Elder Scrolls games, is a continent — one landmass in one world, built to be walked across and fought over, province by province.
• A single planet. Arrakis in Dune is one desert world, and the whole saga is the pressure of that place pressing down on everyone who has to live in it.
• A universe. Ursula K. Le Guin’s Hainish worlds span many planets linked by a shared history, while her Earthsea is a tighter world with its own internal laws — proof that one builder can work at both ends of the ruler.
• A cosmos of its own. Middle-earth sits inside Arda, J. R. R. Tolkien’s full creation — not just a map but the mythology under the map.
• A world whose shape is the joke. Discworld, Terry Pratchett’s flat disc riding through space, is a constructed world where the absurd physics is the premise — and the engine of most of its stories.

Why it matters: scale decides where the pressure lands. A single village built with real streets and real faces can hold a reader or a table tighter than a universe with one thin fact per star. Size is not a score — but knowing your size tells you what you can afford to finish.

Wikipedia calls the degree to which a world follows real-world physics versus magic its “most basic consideration.” Every world sets this dial, and the article shows how far the positions can range.

• Real rules, strictly kept. The mundane science fiction subgenre admits only scientifically plausible technology — so no faster-than-light travel, and a story cannot phone across the galaxy to dodge the consequences of its own choices.
• Magic wearing a lab coat. In Mass Effect, the biotics are described scientifically in-game yet behave like a fantasy mage’s powers; Midnight at the Well of Souls has magic that is real but explained in scientific terms.
• Physics and magic mixed. Star Wars and Stephen King’s Dark Tower series run on both at once — the question is not which side you pick but where you set the dial.

Why it matters: rules create price tags. A world where magic is cheap is a different economy, a different politics, and a different story than one where every working is a bargain struck at a cost. Getting deliberate about the dial is the cheapest worldbuilding you will ever do — it does the deciding for you later.

The article’s “Types of constructed worlds” section sorts its examples by ownership as much as by size. Some worlds are unmistakably one person’s; others exist precisely so that many people can add to them.

• One builder’s world. Middle-earth and Discworld carry a single sensibility — the same hand drew the map and set the tone, which is why they feel like voices and not committees.
• A shared universe. The Star Wars expanded universe and the Arrowverse are written by many authors inside one continuity; in tabletop, campaign settings exist to be shared. Oerth, built for Dungeons & Dragons’ Greyhawk setting, is one of the oldest, and the Forgotten Realms began as Ed Greenwood’s homebrew campaign world before it became everyone’s.
• Worlds that cross fires. The article notes that Lawrence Watt-Evans’s Ethshar, Steven Brust’s Dragaera, and the world of Disco Elysium were built for role-playing games before becoming novel settings — while M. A. R. Barker designed Tékumel well before role-playing games existed, and it later became one of the great game settings.

Why it matters: ownership decides who may add. A single-author world can be one true voice; a shared world needs protocols — a canon, a tone, a reason everyone pulls the same direction. Know which one you are signing up for before you invite other people in.

The last distinction is really about method, and the article borrows the Dungeons & Dragons vocabulary to name it: the official guidelines call the two directions “outside-in” and “inside-out.”

• Top-down (outside-in). Sketch the whole world first — its inhabitants, technology, climate, broad history — then detail downward through continents, nations, cities, towns. The article’s verdict: such worlds tend to be well integrated, the parts fitting together, but they can demand a great deal of work before the setting is actually usable.
• Bottom-up (inside-out). Give one small place the detail it needs — its streets, its faces, its tensions — and let the rest of the world generalize outward from there. This is usable almost immediately, at the risk of inconsistencies creeping in at the edges. Pratchett’s counsel was bottom-up: start by wondering how the fresh water gets in and the sewage gets out.
• Inferred. Leave deliberate gaps and trust the audience to extrapolate. The article calls this especially useful for role-playing settings, where the detail any given session needs cannot be predicted in advance — so you build the parts that press, and let the room fill the rest.

Why it matters: order is a budget decision. Top-down spends before it earns; bottom-up earns before it spends; inferred spends the least and trusts the chairs. None is right — but one of them is right for this week, and knowing which keeps a half-built world from stalling.

Ask one How big is it, really — and is that where you want the pressure to land?

Ask two Where is the physics–magic dial set, and what does that make cheap or costly in your world?

Ask three Is this world yours alone, or a shared campfire — and if shared, what is the canon-keeping ritual?

Ask four Are you drawing the map before the first scene, growing outward from one town, or leaving gaps on purpose for others to fill?

Answer those four and you have described your world’s type — not to file it away, but to know which craft to practice next. A universe-scale top-down world needs different work than a single village grown inside-out, and the tools you reach for should follow.

Distilled from: “Worldbuilding,” Wikipedia — chiefly its “Types of constructed worlds”, “Physics”, and “Methods” sections: en.wikipedia.org/wiki/Worldbuilding. The four questions above are our own arrangement of the distinctions that article draws — read it in full, then bring your four answers to the fire.