If we were talking about modern games, I would totally agree. Indeed, the whole notion of a simple hierarchy would be inappropriate, since cross-breeding is *so* common.

But in period? Really, I'm coming up with very few instances -- so few that I suspect that there's a real memetic shift involved. The notion that games were something that you routinely invent seems to be modern. (Which may have something to do with the creation of games as a business.) In period, games evolved *remarkably* slowly -- it was common for a game to be played for centuries, with only relatively mild tweaks, so the results more resemble biological evolution.

I'm open to being convinced otherwise -- and this being Querki, I may well leave this categorization multi-valued, just in case -- but period games appear to be much more strictly evolutionary. Even basic concepts like "board plus card games", routine nowadays, seem to have been vanishingly rare...