One thing I keep coming back to when it comes to rulebooks and rules explanations, is that players need to understand what they actually *do* in the game.
This is often conflated with which rules they have to follow, or how an action is translated into the game's theme.
But the first step is knowing you have to play cards, or keep others from placing tokens, or combining actions, etc. It's only after understanding these core elements, that you can expand into theme and the limits set by rules.
@RobBBGA We're thinking along similar lines here, yes. I think in order to grasp a game, we need to center the activity itself and then expand from there.
I often encounter explanations that start with what I consider details (hand limit, VP conditions, world building, etc) before talking about play itself.