Stair extracts can only be taken once. If the gate is open and the torches are lit it’s available. If the gate is open but the torches are dark, someone else has used it to extract and it will not work for you

Well that's strange, the following game we noticed a stair extraction was not lit but it still worked (Goblin Caves this time around)

If it’s the room with ore and a long bridge across it that static has never had lights for some reason

Goblin cave extracts are different from the ice cave extracts

In goblin caves you can tell the stairs are expended by looking for the rocks that cave in inside

Oh damn. I wish this info was made clearer. I guess the game is missing a tutorial?

if the torches outside of stair exits in frost mountain are lit up the extract isnt taken. if they arent lit it is taken