Draw a random alien landscape -- methane seas, crystal groves, glass deserts and drowned cities -- each written as what you'd see on landing.
This generator draws from 102 alien landscapes across eight groups, written from the point of view of standing in them: what the ground does, what the air is like, and what will go wrong. It covers liquid seas that aren't water, growth that isn't plants, and the built and ruined terrain left behind by somebody else.
Every result here is drawn using crypto.getRandomValues() -- the Web Crypto API's cryptographically secure randomness -- instead of Math.random(), so it's genuinely unpredictable, not just statistically random. Learn more.
Game masters use it for the moment the ramp comes down and the party needs somewhere to be. Writers use it to avoid describing yet another red desert, and it works as a visual prompt on its own. In the Random Alien World preset it's the surface your world actually has.
Generate draws one biome at random using the site's cryptographically secure randomness, guaranteed not to repeat whatever result is currently showing in single-result mode. Filter by terrain type, or raise the amount to draw several and map a whole continent at once.
A sample of what this generator can draw, spread evenly across the full list:
Yes -- set the amount higher and Generate will draw that many at once, which is a quick way to sketch a world with real regional variety instead of one climate everywhere.
Several are real terrain types found off Earth: methane seas on Titan, penitente ice fields, cryovolcanoes, nitrogen glaciers and dry valleys all exist. The rest extrapolate from real chemistry.
Scale. Alien World gives you the planet as a whole -- its class, orbit and history. Alien Biome gives you the specific landscape you're standing in, and one world can hold many.
Yes -- deselect Built & Ruined in the filter to keep everything natural.
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