Hypertext d20 SRD: This is everything from D&D that is public domain
for people to use/reproduce/etc. It is an excellent reference site whether
you own the books or not!
Domesday Book: This is a neat little tool that will help you build
up demographics for a kingdom. You input the variables (such as size
of the land area) choose the setting, and then it puts in the estimated
numbers. I used this a lot for my initial world-building of Sinari.
putting this under free, because those are the ones that I grabbed and
played with. This site has lots of different kinds of map-making tools,
for taverns, cities, dungeons, etc. Some are free (under downloads),
some are purchasable.
Maker: I don't remember
how I found this, but I was searching for icons to help me build layouts
for buildings in Sinari. This
is actually a really cool little tavern/inn generator, and well worth
This is a kingdom generator that Daan over at Redblade made. The very
first thing I did was click +10,000 years, and the program warned me
that it would take a long time to which I scoffed and clicked ok. Sadly,
after ten minutes and only 20% of the way through I force-quitted the
program. Hehe. Anyway, this tool will create an entire history of people,
families, cities, everything. It's really cool. The name generator portion
of it is lacking a bit, but it's still fun to play with.
Not So Free:
the best of the worldbuilding software out there in terms of raw power
and possibilities. I haven't used the new Campaign Cartographer 3, but
I have played around with the older version and all the demos. The learning
curve was a bit challenging, but there are 'getting started' guides that
are very helpful. The software is a bit expensive I think if you're just
a casual DM, but if you're not afraid of a price tag this is some really
cool stuff. The fractal terrain maker brought my laptop to it's knees,
so avoid that if you have a slower PC.