"The world is made up of characters, objects, and scenery"
The Entity primitive is what makes the characters and objects, and any scenery that has mechanics. I should note that this is all purely about the mechanics of rpgs, no fluff or story.
Cool. Why I mention "Character, Objects, and Scenery" is they form an exclusive list of categories - if a thing isn't one of those three _it doesn't exist_.
I'm more used to breaking the universe down into manageable chunks rather than building up to them
. As an item becomes more defined by progressive layers of categorization it picks up hooks that guide interactions.
"ALL Characters can be further subdivided into Allies, Bystanders, Enemies."
"ALL Characters are either Standard or Special."
I thought that maybe this was what you were describing with tags? I'm just looking at the importance of exclusives sets of tags rather than free-standing identifiers.
"All characters have 6 attributes"
"The six character attributes are an ordered list of Strength, Dexterity, Constitution, Intelligence, Wisdom, Charisma"
That would be defined first by making an Entity template that has six stats for those attributes, and second by rules that would make use of them and thus differentiate them from other stats (though I have yet to make a way to express that part).
With the ordered list its a tool for presentation - if Intelligence and Strength ever appear together as equals, its always listed Strength first, then Intelligence - is a situation where the order supersedes the default of presentation in alphabetical order.
"Initial attributes are purchased by spending a pool of character points according to the following table..."
I currently don't have a way to express that, but it would be in a rule section.
I find your definition of pool curious. To me a "pool" as a mechanical term refers to a "resource pool" - a body of currency that enables choices. Compare: 5 dice that must be spent together is a value, 5 dice that may be spent in multiple ways is a pool. And a critical question about pools is how often do they refill. your character point pool never refills. Your action dice pool refills at the beginning of each session. Your spell point pool refills at the beginning of each scene. Your Edge (pool) refills only when you take actions that fill it.
Hopefully this sparks some evolution