John Leslie and Hostage Chess

I learned recently that the philosopher John Leslie is the inventor of a chess variant, Hostage Chess. Left-click on the hyperlink and scroll down.

I have never played any of the chess variants, and they don't interest me. Penetrating the arcana of standard chess has me sufficiently occupied. Such a patzer am I that I could not explain the Lucena and Philidor positions without consulting the manuals. But could you? And my endgame savvy is weak. My excuse is that I didn't get seriously into chess until I was deep into middle age.

I can say of Caissa what Augustine said of the Eternal Unchanging Light: "Too late have I loved thee." Not that the former takes the place of the latter, you understand.