Power and/or Toughness X

So, whenever a card with power and/or toughness equal to X or * wasn't in play X or * were always considered 0.
There were changes to this and now whatever checks that variable does so in a continuum time line, wherever that creature might be.

Originally Posted by Comp Rules
208.2. Some creature cards have power and/or toughness represented by a * instead of a number. The object has a characteristic-defining ability that sets its power and/or toughness according to some stated condition. This ability functions everywhere, even outside the game.