What I am going to describe probably exist somewhere in books or on some web sites. But one thing for sure, it does not exist all at the same place.
I'll start with an example:
Let say you design a space conquest game and you need to design a series of technologies that could be developed through the game.
My first reaction is to look at the list of technologies in the "master of orion 2" as a source of inspiration to create my own technologies. Many things might be also be imported directly. For example, the "holographic simulator" technology is pretty common to many sci-fi universe and not specific to the world of "Moo 2".
Now I could have taken any video game, sci-fi book or even board games as a source of inspiration because I cannot simply spawn out of my mind let say 50 technologies like that.
The problem is that Master of Orion is not in any way THE reference for that kind of information. There is probably also a lot of things which are not in master of orion.
So my idea is:
Could there be for example an encyclopedia or a database of all the sci-fi technologies that have been designed so far. Technologies is just an example, but you could do the same for many other things. Here is a couple of random example:
Races (elves, dwarves, etc.)
Buildings (Barrack, quarry, mill, etc)
City ranks ( town, city, metropolis, etc)
Pieces of machines ( wheel, shock, pump, gear, etc)
Spells (Fire ball, lightning storm, Charm, etc)
You get the idea!
Having a web site where everything can be there could be interesting. When player needs inspiration to theme their game, they go check some lists and note down what is interesting.
The only problem is that every things must be public domain. For example, the race of elves is public, but the race "Protoss" and "Zerg" is specific to starcraft. So these words should not get in the database. Still, I am not sure if it is pretty obvious to determine if it's public domain.
For example, elves are probably public domain, but who created it first? I know that some names were modified like the treant which is a modification of Tolkien's creature. The werewolf which is a modification of the wolfman.
Do you think that kind of database could be useful in your design?
Do you know any website that contains that kind of information?
Thank You