You are playing Nightmare mode.

Gollum cannot take damage.

Setup: Search the encounter deck for The Lower Gate and set it aside, out of play.

Forced: When stage 3B is revealed, add The Lower Gate to the staging area.

Begin with the standard quest deck and encounter deck for the Dungeons Deep and Caverns Dim scenario.

Remove the following cards, in the specified quantities, from the standard encounter deck:

3x Goblin Miners

3x Goblin Axeman

3x The Goblins' Caves

3x Grip, grab! Pinch, nab!

1x Not fair! Not fair!

Then, shuffle the encounter cards in this Nightmare Deck into the remainder of the standard Dungeons Deep and Caverns Dim encounter deck.

Finally, flip this setup card over and place it next to the quest deck. Its effects remain active throughout the game, which is now ready to begin.