"Growing" or "Evolving"

Using a set of rules (usually probabilistic) to get a terrain from some starting state (ocean or scattered islands) to continents and islands. This could be a cellular automaton (like Conway's Life, but more complex), or some other type of grammar (e.g. L-Systems). The more context you can consider, the better. Rules can be hard coded or can be represented as probabilities in (an) array(s).

Advantages: Any terrain feature can be derived during this step, including vegetation and rivers, if you write the rules that way.

Disadvantages: Like any cellular automaton, it takes a while to run. It's also likely that you won't have any easily automated way of knowing when it's "done".

Here's a related message found on Usenet:

```Re: Land generator algorithm

From: dwarren@alpha.netusa.net (Douglas Warren)

While not exactly what you are looking for, I have developed a similar
though somewhat different technique then those that have been listed here.
I seeded a 2D array with a base land type (I believe Oceans) and then
using a semi large markov chain matrix, take the markov row of the land
that is to the east of the current, to the Northeast, to the north, and to the
northwest, sum the values of the collumn, then grab a random variable from
1-4.  Check the expanded column to see what type of land that may have and
place it there.  This is just for the land type not actually the altidue,
it does look rather relistic as it can simulate a river running through
a continent, and is amazingly fast.  The hardest part is deciding what
the matrix should look like, that is given an ocean here what is the
chance that the next element is a forest?  Or that it remains an ocean.
As I'm rather new to the game design program, you may want to take all this
with a grain of salt, and I'd apperiate any comments from people who
have done this before.
```

Related pages

Feature-based Fractal Terrain Generation - Jason Stout's thesis work