How Procedural Generation Creates Infinite Game Worlds
Photo: Daniel J. Schwarz / Pexels
In 1980, two programmers working on a Unix mainframe at UC Santa Cruz got tired of drawing dungeon maps by hand, so they wrote a program to do it for them. That program was Rogue, and it is now widely credited as the first video game to generate its content algorithmically rather than by design (Wikipedia: Rogue). Forty-six years later, the same basic idea — feed a number into a set of rules and get a world out the other end — powers games with 18 quintillion planets, roguelikes that have sold tens of millions of copies, and dungeon crawlers that regenerate themselves every time you walk through a door.
This is not one company's trick or one game's gimmick. It is a design philosophy with its own history, its own internal arguments, and its own hard-won lessons about what randomness is actually good for. This piece traces that history across four decades and four very different games — Rogue, Elite, Diablo, and No Man's Sky — to show how "infinite worlds" went from a practical shortcut for two students with no art budget to one of the defining techniques of modern game design.
Key takeaways
- Procedural generation uses algorithms fed by a random seed to create content — levels, galaxies, dungeons, items — that would be impossible or impractical to hand-build at scale.
- Rogue (1980) is widely credited as the first game to generate its dungeons algorithmically, giving its name to the entire "roguelike" genre that followed (Wikipedia).
- Elite (1984) used a modified Fibonacci-sequence algorithm to generate 2,048 star systems across eight galaxies from six-byte seeds, at a time when home computers had roughly 32 kilobytes of memory (Rabidgremlin, "Creating a Universe").
- Diablo (1997) used a Dynamic Random Level Generation system, borrowed conceptually from the roguelike Angband, to rebuild its dungeons from scratch on every play-through (Boris the Brave, "Dungeon Generation in Diablo 1").
- No Man's Sky (2016) generates roughly 18.4 quintillion (1.844 × 10¹⁹) unique planets from about 600,000 lines of code, combining noise functions with L-systems for plant life (Rambus, "The Algorithms of No Man's Sky").
- The recurring lesson across every era: unconstrained randomness produces variety, not quality. The games that hold up are the ones that constrain their randomness with hand-designed rules.
What "procedural" actually means, and why it started as a workaround
"Procedural" refers to a procedure — a defined sequence of steps. In game development, procedural generation means using an algorithm to produce content at run time, rather than an artist or designer placing every element by hand. The critical ingredient is the seed: a starting number fed into a pseudorandom number generator, which then produces a long, deterministic sequence of numbers that look random but are perfectly reproducible. Feed the same seed into the same algorithm and you get the exact same output, every time.
It is worth being blunt about why this technique was invented in the first place: it was not a creative philosophy at the start. It was a practical solution to a resource problem. Michael Toy and Glenn Wichman, the creators of Rogue, were writing an adventure game on a university mainframe with no art department, no level designers, and no way to distribute large content files across a shared academic network. Hand-authoring dozens of unique dungeon layouts was not an option available to two students. Writing a small program that could generate an effectively unlimited number of layouts from a few kilobytes of code was (Wikipedia: Rogue).
That constraint-driven origin is a pattern that repeats throughout this history. Elite's developers faced 32 kilobytes of BBC Micro memory and still wanted a galaxy-scale trading game. No Man's Sky's four-person studio wanted a universe and could not employ enough artists to paint 18 quintillion planets by hand. Procedural generation has always been, first, a way to do more with less — and second, once developers realized what it could produce, a design philosophy in its own right.
Rogue and the birth of a genre named after itself
Rogue's dungeons were built from a grid of connected rooms and corridors, populated with monsters and items drawn from tables, all regenerated from scratch each time a player descended a level. Nothing about any individual dungeon was designed by a human. The game's defining feature, alongside its procedural maps, was permadeath: when your character died, the game ended and your progress was gone, with a new dungeon waiting on the next attempt (Wikipedia: Rogue).
That combination — algorithmically generated levels plus permanent death plus turn-based, grid-based movement — became influential enough that an entire genre now bears the game's name. "Roguelike" originally described games that copied Rogue's mechanics closely: NetHack, Angband, and Ancient Domains of Mystery among the classic examples. Over time the term loosened into "roguelite," describing any game that borrows procedural levels and run-based structure without the strict permadeath or turn-based combat — a lineage that now includes Hades, Dead Cells, Slay the Spire, and The Binding of Isaac.
Why did a university side-project define a genre for 45 years?
Rogue solved a problem every game designer eventually runs into: hand-crafted content is finite, and players exhaust it. A procedurally generated dungeon never runs out, and because death resets progress, players return to the same generation system dozens or hundreds of times rather than experiencing it once. That replay loop, invented out of necessity, turned out to be more compelling than anyone expected.
Elite: procedural generation at galactic scale, on a machine with no memory to spare
Four years after Rogue, David Braben and Ian Bell released Elite for the BBC Micro, a home computer with roughly 32 kilobytes of usable RAM. Elite was a space trading and combat simulation set across eight galaxies, each containing 256 star systems with their own economies, governments, and populations — 2,048 systems in total, none of them stored as data (Grokipedia: Elite).
Storing that much handcrafted content on a cassette tape or floppy disk in 1984 was not physically possible. Braben and Bell's solution was a modified Fibonacci sequence algorithm: a six-byte seed value ran through the sequence to deterministically generate a star system's position, name, economy type, government, and population, all computed on the fly as the player traveled (Rabidgremlin, "Creating a Universe"). No system data lived on disk. The entire galaxy was a formula.
The trick that made Elite matter isn't the algorithm — it's what the algorithm was used for. Perlin noise generates terrain height. Elite's Fibonacci-based generator produced something more abstract: names, factions, and economic relationships, the connective tissue of a simulated society rather than a simulated landscape. That distinction — generating meaning-bearing data, not just geometry — previewed a much later ambition: games that generate not just where things are, but what they mean to the player exploring them.
Diablo: procedural generation meets action-RPG combat
By 1996, Blizzard North's David Brevik was designing Diablo, an action role-playing game that took direct inspiration from Angband, itself a Rogue descendant. Diablo's core structural bet was that its 16-level dungeon should not be a fixed, memorizable layout the way most action games of the era were. Instead, Diablo used what its designers called a Dynamic Random Level Generation (DRLG) system: every time a player entered a dungeon level, the game built a new one from scratch, mixing procedurally placed rooms and corridors with pre-designed "set piece" areas like specific crypts or mazes that would drop into the generated layout intact (Boris the Brave, "Dungeon Generation in Diablo 1").
Technically, Diablo's room generator relied on recursive subdivision: starting with the full dungeon area, the algorithm carves out randomly sized rooms (roughly four to nine tiles per side in the original implementation), then recursively subdivides the remaining space, connecting the results with corridors (Boris the Brave). The result reads as an organic dungeon crawl even though no human placed a single wall.
Diablo also generalized procedural generation beyond geometry into loot. Every weapon and piece of armor could roll randomized affixes — bonuses to damage, resistance, or attributes — drawn from weighted tables. This is the mechanism now familiar from nearly every loot-based game that followed, from Path of Exile to Borderlands: the level layout gives you a reason to keep moving, and the procedurally generated item table gives you a reason to keep killing things once you get there.
How is dungeon generation different from terrain generation?
Terrain generation (Perlin or Simplex noise, as used in Minecraft) produces continuous height maps: smooth, organic-looking elevation data across a landscape. Dungeon generation, as in Diablo or Spelunky, produces discrete, connected structures: rooms, corridors, and guaranteed paths between an entrance and an exit. The two use different underlying algorithms because they are solving different problems: noise functions are good at "what does this look like," while room-and-corridor generators are good at "is this traversable."
Spelunky and the discipline of constrained randomness
Derek Yu's Spelunky, first released in 2008 and remade in 2012, is frequently cited by designers as the clearest demonstration that procedurally generated levels can be as carefully tuned as hand-authored ones. Spelunky does not generate arbitrary random geometry. Each level is built from a 4×4 grid of rooms, and each room is filled by selecting from a library of hand-designed room templates, subject to hard constraints: a guaranteed path must exist from entrance to exit, no level may be mathematically unsolvable, and harder room types and enemy placements are gated behind depth thresholds.
The distinction matters because it separates two very different failure modes. In a poorly constrained procedural system, a player can die because the level itself was broken — an unreachable exit, an impossible jump, a key item that never spawned. In Spelunky, a player can die to bad luck (a spike trap in an unlucky spot, a shopkeeper turned hostile at the wrong moment), but the game's rules guarantee they never die to a level-design failure. That guarantee is the entire difference between "random" and "well-designed random."
Analogy: think of Spelunky's system like a jazz musician improvising over a chord progression. The notes played each time are different — that is the point, that is where the surprise lives — but the chord progression itself is fixed, composed, and rehearsed. Nobody would call jazz improvisation "random"; it is structured freedom. Spelunky's rooms are the notes; its connectivity and difficulty-gating rules are the chord progression.
No Man's Sky: what happens when you push the scale to its logical extreme
Hello Games' No Man's Sky, released in 2016, represents the most ambitious scaling of procedural generation attempted in a shipped commercial game: approximately 18.4 quintillion (1.844 × 10¹⁹) unique planets, generated from roughly 600,000 lines of code (Rambus, "The Algorithms of No Man's Sky"). Every planet has a persistent seed, and the game generates terrain, atmosphere, flora, and fauna from that seed at the moment a player arrives, then reproduces the identical planet if the same player, or a different player, returns to the same coordinates.
The generation stack combines several distinct techniques rather than one. Terrain uses noise functions in the Perlin/Simplex family. Plant life uses L-systems, a grammar-based generation method developed by biologist Aristid Lindenmayer in 1968 to model the branching growth patterns of real plants, which No Man's Sky repurposes to grow procedural flora (Rambus). Creatures are assembled from a library of interchangeable body parts, scaled and recolored according to the planet's seed. Notably, developer Sean Murray discussed a mathematical "superformula" (developed by Johan Gielis in 2003 to describe a wide range of natural and biological shapes) during pre-release interviews as an inspiration, but later stated on social media that the patented superformula itself was not actually used in the shipped game (Forbes, "Did 'No Man's Sky' Steal a Scientist's Superformula?").
The launch problem, and why it is the single most important lesson in this entire field: No Man's Sky's 2016 release was widely criticized on the grounds that its planets, while genuinely unique in a technical sense, felt interchangeable in a way that mattered to players. Terrain varied; the emotional experience of visiting one planet versus the next largely did not. The system had achieved variety without achieving meaning. Over the following years, through a long series of free content updates running from 2016 into the 2020s, Hello Games layered hand-crafted narrative missions, base-building, and multiplayer onto the procedural foundation — shifting the generated universe from being the entertainment itself to being the backdrop against which more deliberately authored content happens.
That arc, played out publicly and at enormous scale, is the clearest real-world case study of the tension every procedural system eventually confronts.
The variety-versus-quality problem, and why it never fully goes away
Every example in this piece, from a 1980 mainframe dungeon crawler to an 18-quintillion-planet space game, runs into some version of the same wall: pure randomness is easy to generate and boring to experience. Meaningful variation is what players actually want, and meaningful variation requires human-authored constraints layered on top of the random process.
| Game | Year | What it generates | Constraint mechanism |
|---|---|---|---|
| Rogue | 1980 | Dungeon layouts, monsters, items | Room-and-corridor grid with guaranteed connectivity |
| Elite | 1984 | 2,048 star systems, economies, governments | Fibonacci-seeded formula, fixed galaxy count |
| Diablo | 1997 | Dungeon levels, item affixes | DRLG recursive subdivision + hand-built set pieces |
| Spelunky | 2008/2012 | Level layouts from room templates | 4×4 grid, guaranteed solvable path, depth-gated difficulty |
| No Man's Sky | 2016 | 18.4 quintillion planets, flora, fauna | Noise + L-systems + creature-part libraries, later layered with hand-authored missions |
Table: five landmark procedurally generated games and the constraint systems that kept their randomness from becoming noise.
The pattern across the table is consistent: every game that is still discussed as a design touchstone paired its randomness with an explicit rule set that a designer could reason about and tune. The rule set is not a limitation on the procedural system. It is the actual design work. The algorithm generates volume; the constraints generate quality.
Where procedural generation reliably works, and where it still struggles
Reliably strong:
- Terrain and environment. Noise-based generation produces geologically plausible landscapes, and because players have no memorized "correct" version of a mountain range to compare against, variation reads naturally as exploration rather than error.
- Dungeon and level layout, when constrained. Diablo and Spelunky both demonstrate that connected, navigable, difficulty-appropriate spaces can be generated reliably as long as the generator enforces solvability.
- Item and loot variation. Diablo's affix system, and its descendants, work because players are evaluating discrete numerical outcomes (this sword is better or worse than that one), a comparison procedural systems handle well.
- Simulated economies and factions. Elite's system shows that generated data can extend beyond geometry into abstract systems like trade routes and governments, as long as the underlying rules (supply, demand, political alignment) are internally consistent.
Still genuinely difficult:
- Narrative causality. A story that means something requires specific events to happen in a specific order for specific reasons. Procedural systems are good at producing surprising combinations of pre-written fragments (as in modern narrative games), but they are still poor at generating causally coherent plots from scratch.
- Iconic, singular moments. The moments players remember years later, a specific boss fight, a specific vista, are almost always deliberately placed by a human designer who understood the emotional beat they wanted to hit. No procedural system has reliably reproduced that kind of authored intentionality.
- Puzzle design. A good puzzle needs to be solvable, non-obvious, and satisfying to solve, three properties that are difficult to guarantee simultaneously through random generation without extensive constraint solving.
Why did roguelikes survive as a genre for 45 years while other procedural experiments faded?
Roguelikes solved the variety-versus-quality problem early by embracing it rather than hiding it: permadeath means the player's relationship with any single generated level is inherently short, so imperfections matter less, while meta-progression across many runs (unlocked characters, items, or story beats, as in Hades) supplies the sense of authored intentionality that any individual generated level lacks. The genre never needed each dungeon to be a masterpiece. It needed each dungeon to be different enough to justify the next attempt.
Does procedural generation actually save development time?
It depends what is being measured. Content volume per hour of development is dramatically higher: a well-built generation system can produce far more explorable space than the same team could hand-author in the same time. But building a good generation system, one with the right constraints, is itself a significant and specialized engineering effort, and the quality ceiling of generated content is generally different from, not automatically lower or higher than, hand-crafted content. Teams that treat procedural generation as a shortcut around design work, rather than as design work in a different form, tend to ship the kind of "technically varied, emotionally flat" content that No Man's Sky was criticized for at launch.
What is the difference between a roguelike and a roguelite?
A roguelike traditionally preserves Rogue's core mechanics closely: procedurally generated levels, permadeath with no persistent progress between runs, and turn-based, grid-based movement. A roguelite keeps procedural levels and a run-based structure but relaxes one or more of the stricter conventions, most often by adding meta-progression that persists across deaths (unlocked upgrades, story beats, or currency) or by using real-time rather than turn-based combat. Hades and Dead Cells are commonly described as roguelites for this reason.
Can two players ever get the exact same procedurally generated world by accident?
In principle, yes, if the seed space is small enough and two players happen to enter the same seed. In practice, modern games use seed spaces large enough (Minecraft's are 64-bit integers, offering roughly 18 quintillion possible values) that accidental duplication is not a practical concern; deliberate seed-sharing between players who want to visit the exact same generated world is a well-established community practice rather than a coincidence.
Did No Man's Sky actually use the mathematical "superformula"?
Developer Sean Murray referenced the superformula, a 2003 equation by Johan Gielis capable of describing many natural and biological shapes, in interviews before the game's release. After launch, he stated publicly that the patented superformula itself was not used in the shipped game, even though it may have informed the studio's broader thinking about generating organic-looking shapes (Forbes).
Why did Elite's developers need an algorithm instead of just storing the galaxy as data?
The BBC Micro that Elite launched on had roughly 32 kilobytes of usable memory, nowhere near enough to store handcrafted data for 2,048 star systems with names, economies, and governments. A six-byte seed run through a Fibonacci-based formula could regenerate any system's full data on demand, using a fraction of the storage a handcrafted database would require (Rabidgremlin).
What made Diablo's dungeon generation different from a simple maze algorithm?
Diablo's Dynamic Random Level Generation system combined algorithmically carved rooms and corridors, built through recursive subdivision, with pre-designed "set piece" areas such as specific crypts and mazes that the system would drop intact into the generated layout (Boris the Brave). That hybrid approach, part algorithm and part hand-authored content, let Blizzard North guarantee memorable, deliberately designed encounters inside a dungeon that was otherwise different on every visit.
Is Rogue's dungeon generator still considered good by modern standards?
Rogue's generator is simple compared to modern systems and would likely feel primitive if released today, but its historical significance is not really about technical sophistication. It is credited as the first game to make procedural generation the core of its design, and the entire "roguelike" genre, spanning NetHack, Angband, and dozens of modern successors, traces its name and its foundational mechanics directly back to it (Wikipedia).
Why do some procedurally generated games feel more "alive" than others with similar technology?
The difference usually comes down to how much of the generated content is geometry versus how much carries information the player can interpret meaningfully. A landscape generated purely from noise reads as scenery. A dungeon generated with guaranteed connectivity, difficulty pacing, and occasional hand-placed set pieces reads as a designed challenge. The technology in both cases can be similar; the difference is how tightly the randomness is constrained toward player-legible meaning rather than raw visual or spatial variety.
The takeaway
Procedural generation's forty-five-year history is really a single argument, restated by every generation of developers who take it on: an algorithm can produce essentially unlimited content, but volume was never the hard problem. The hard problem, the one Rogue's creators stumbled into with two kilobytes to spare and No Man's Sky's developers relearned in public at a much larger scale, is getting a random process to produce content that feels intentional. Every game in this history that is still cited as a landmark, Rogue's connected dungeons, Elite's seeded economies, Diablo's hybrid set-piece system, Spelunky's guaranteed-solvable rooms, solved that problem the same way: by wrapping genuine randomness inside rules a human designer chose on purpose. The algorithm supplies the infinity. The constraints supply the reason anyone would want to explore it.
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SciHub101 is an independent science and technology publication founded and edited by Buğra Sözeri, a software engineer and app developer based in Türkiye. AI tools assist with drafting and research. Source documentation in the existing archive is uneven, and articles are being reviewed and corrected. The Editorial Team byline identifies editorial responsibility; it does not certify specialist or independent human review. Where we compare products, anything built by our own team is labelled as such — see the editorial guidelines and About page for how corrections and disclosures work.
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