So called “Curse of Fantasy” – a Map – is inevitable in computer game.
Highly improbable and arbitrarily placed countryside elements. Deserts in places which should be lush jungles and Rich Trade Capitals in places which shouldn’t even provide enough for small village to exist. Random 100years old ruins. Geographical and cultural mayhem.
Fatal mistake that is oh-so-often made is to start with clean sheet of paper, timeline and checklist of mountain ranges, countries and cities. Huge plus is given if continent has fjords.
However, there is much better approach: Play a computer game! Silly, eh? Does playing games instead of working have history of getting people fired per change?
This is not really bad idea thou. Saves some research and it is actually fun.
Phase one: how does realistic planet look like?
Here, Sim Earth helps. Draw your generic land and watch it come alive, toy with parameters and ensure that your mount Doom is in real volcanic active area. That your jungles are in right spot. And that your highlander comes from actual highlands.
As bonus, you get weather patterns, average temperatures, ocean currents and whatnot in one neat package! And you can simulate evil god nuking your version “Atlantis”. Neato.
So, go ahead, start with painting map of your favorite fantasy land and watch it become dry wasteland because author kinda overdid it with mountain ranges which provide excellent shelter from rain.