20. What is the most challenging but rewarding system have you learned?
Fate (Evil Hat Productions) — not because it’s inherently complicated, but because it required shifting mindsets altogether. I’ve described in a previous post how I played Fate-powered games for several years without “getting” it, and how things changed when I tried the Fate Core edition.
Essentially, I had to learn to switch from a pass/fail mindset (choose a skill and roll to see if you succeed) to a fictional positioning mindset (this is what a character would do, roll to see what direction the story takes, create mechanically reusable little bits of fiction.) Not only do I now adore the Fate system, it has also changed how I approach other games.
The Reef 
I may have to quote you when trying to explain Fate to people and why it can be both difficult to get your head around but super liberating once you do.
Very interesting blog post – I very much agree that Fate does require a mindset, particularly when used to more binary pass/fail systems.
That same thing just passed to us! we decideto start again, core basic, from scratch.
This new approach is something else, the new game is awesomely different!