Coup d'etat! Coup d'etat!

From the House Rules thread

What do you mean? How would it work? Does it apply to the aegis?

As I understand it, it means that, say, a Circular Ward against Demons or, even it it penetrates, will not nescessarily stop a critter from entering. How so?

As an aside, I'm all from converting personnal wards into soak so as to avoid the "invincible to swords" effect, but I'm not sure nerfing circular, drawn wards is a good idea, since it is already so much easier to just blast creatures.

=> Could you explain a little more?