I’m looking for resources on game design — not the coding part, but just the design. The resources don’t even have to be specific to computers.
So far, I’ve found a book and card deck called Art of Game Design. Does anyone know of other good resources?
Related thread: RPG Game Plots
The second point is true. Games should be easy to pick up, but hard to master. I.e. chess or Go. And the rules should be relatively simple.
I’ve noticed the great classic games have replay value, i.e. Tetris, Starcraft.
This means that anyone can enjoy these games without the need to study a rulebook or take some kind of course beforehand, which is why they are both successes.
I probably need to work on that. 
That site mentioned Coursera, so I searched and found some free courses. At least some of them look design-related.
I found some videos on YouTube that show brief clips of many old games in a short period. I thought they were interesting for ideas.
The #gamedev and #screenshotsaturday hashtags on Twitter also have interesting examples of what people are building.
Not sure how much game design is mentioned in this group, but it’s the one ran by the pong series I watched, the focus may be more on game patterns than design, but may some of the resources may be helpful home team game dev
That looks interesting.
I’m not sure if this has been mentioned yet: “Random Idea, Plot and Inspiration Generators for Art and Writing”