Yes okey, these days I am actually trying to find a good way to talk about that subject.
To be clear about the RPG part of that Atlas :
First it will include an illustrated "how to play" at the beginning of the book.
It will be made with simple rules so people who don't know about rpg tabletop can learn and try.
I think to be able to play without some expensives rules book can be a good start and lead people to see more and by more advanced book if they want to improve.
Mostly this part will included advises for players and game master that I think can be useful to everybody even people who have already play.
To give you an example those illustrations will be a part of explaining how to think like your character and use his/her ability to do an action :
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After that, let say your are a game master now able to create a game, using a rulebook or not :
You create an adventure where your player have to find a treasure in a cave.
With the Atlas you can pick a world and put your adventure in it, doing so will be a lot easier for the game master to add details in his adventures, encounters and such.
It can even be a help during the game to improvise, if your players go in a way you didn't think at first, the map can help to find encounters like giants if they goes near some montains (just an other example)

Some says that one picture is worth as much as a thousand words and I believed that. So in some books you can find spreadsheet to find encounters, locations etc. I just wish to do the same but only with pictures.

I did not ask for the artists to make "rpg maps" like the ones withs squares to be able to deal combats and such. It's also to let artists goes in their ways and let them created things of their own.
This way I have a collection of worlds really differents and who goes a bit away from "classic fantasy".

My wish here would be to use the same things that everybody use while reading a comic book. When you draw a comic book you don't have to draw the background in every frames because after seeing once the reader unconsciously picture it anyway.
So if playing a rpg tabletop game with one of those world, let say with an old cartoon style, players will affecting their way to pictures what the game master say in a cartoon way.

All that make me say that this book can be an useful tool. It's not a magic tool but i trully think it can be really cool.
Did my explainations looks good for you ?

Anyway thanks Red for the review, I appreciate it and it's a good exercice to try to explain my project better.