This dungeon is much like Dungeon of the King (2/DU) which lets this player not ask for permission to use support cards. There is now no reason to ever play that card, as this one is clearly better.

Firstly, this card broadly says any card that requires permission while Dungeon of the King lists each type of support card separately, so new card types can be protected as well.

The other part that puts this card a step above if the first part, that makes this player immune to instant defeats. The definition of "instant defeats" is very important to the use of this card.

The working definition is "a card which defeats a champion based solely on champion type or with the words 'instantly defeat' on them". This doesn't even work on cards that say "automatically defeat", like the Earth Elemental (60/PO). This means that you can completely ignore any card that would instantly kill you, so it can be very dependent on timing of the play. For instance, say you are using Level the Playing Field and an adjusted level 8 champion, and the opponent plays The Dreaded Ghost (246/4th), which drains 9 levels and discards an opponent if reduced to 0 or below. This would not be protected against since it doesn't fit one of the above requirements.

The best way to deal with this is to play cards that restrict cards your opponent can play (anything that doesn't say permission) or cards that are high level that help insure battle. Examples include Tail Sweep (92/DR), Master Illithid (53/DU), and the always horrible Fighting Dirty! (3/DU-chase).

This does not extend to cards you are playing. For instnace, if you are using the Ebony Cup of Fate (8/FR-chase), and are defeated when you find an artifact in the opponent's hand, you do lose.

I don't recommend this card except a deck expecting battle where they know the opponent uses "instant defeating" cards.