Q: What happens if the third Rule you turn up with Pandora’s Box is Inflation?

What is more immediate, the Rule or the Action? In other words, does the playing of Inflation close the Box, so to speak; or does it affect the Box, meaning you have to draw to a fourth rule?

A: It goes to 4. Since everything happens immediately in Fluxx, Inflation is applied to the Action that caused it to be played. So yes, you’d continue to a fourth rule if Inflation came up during Pandora’s Box. (Similarly, Draw 2 and Use ’em would instantly become Draw 3 and Use ’em if Inflation was one of the two cards drawn.)

Adventure Time includes the Inflation analogue, Mathematical! Inflation is also available as a promo card to add to any Fluxx deck.