Wohoooo, new fortification cards! This sounds like this cycle might make control decks stronger.

I wonder what will define a fortification - the lack of power or the trigger when the zone is attacked?

If the latter then we already have three - Anointed Cauldron, Cauldron of Blood and Sacred Glade. If the former then we have a whole lot of similar cards(13) with the traits Siege and War Machine and a few other with traits Rune, location and building. Possible interaction between Siege, War Machines and Fortifications?

I'd suggest that the definition of a fortification would be the Fortification keyword. Just a hunch.

Like Wall of Maggots :

Budmilka_fr said:

LOVE THIS CARD. Definitely going into my corruption deck.

Missed one more possible Fortification - Rune of Fortitude.

Also not a fortification.

Think about the way Treasure Vaults reference buildings (i.e. support cards with the "Building" trait). Fortification is just a new trait.