Alternate wording:
When only one of a creature is on the field and dies, no other may be played (until this card is destroyed)
thanks for analysis/feedback
alternate wording - I like the bit 'becomes extinct' where extinct is a new scenario. First bit I might use though when I make final adjustments
Quick question. How would this work with a Schrodinger's Cat? I I trigger Dead/Alive, and it's the only one in play, does that mean I can't play any more Schrodinger's Cats?
Good question.
I think Schrodinger's Cat should not become extinct when it triggers dead/alive because it hasn't left the playing field (is actually still alive...) not sure if that causes major issues with programming, but think that is how it should work with SC.
The way I see it - when SC 'dies', at that precise moment you couldn't play another if Extinction was in the game, but then it's alive again, and in play, so you can play another SC.