She does that with each jack. She continues that until she has done all ten jacks. Then, if she completes that round without difficulty, she starts again with a more difficult rule. There are a few of these rounds that are already invented, but it is common for the winning player to invent the next game. And what you'll find, I think, if you go through a careful study of these various types of games, is that there are similarities and differences.
Poker is like chess in certain ways.
They both have clear rules and the winner is likely to have practice and skill. But they are different in some ways, too, and if you look at how they are different, you'll find other games that are not different in these ways, but different in other ways. Here is the key move, and the new metaphor that LW extends to replace the old Platonic metaphor of essence. Notice Al and Jack have the same eyebrows, while Elmer and Bob have the same ears and Al and Bob have the same smile. There is no common feature among them yet they all resemble each other.