MArcomage

"Enemy production next round x0"

Unfortunately, persistent effects aren't supported. Whatever a card does, it has to resolve during that turn, so affecting numbers during the following turn can't be done.

I see; for some reason I'd thought production multiples were different. Can you think of something else the card can do that would have a semi-immediate effect to slow down a game's escalation on both sides?

You could reduce the opponent's stock by the amount of their facilities (production). Mathematically, in theory, it will have the same result as "next round's production x0", provided that the opponent do not raise their stock or facilities in the next round.

Well, ideally it would actually stop stock increase completely for those two rounds; still working even if a player had 0 in a resource. I think I'll need to rethink that part somehow; it shouldn't have an effect which anything like MotP or Judge would work on.