Allow us to tie a rope onto the Chasm in the Key room

[yyyyyyyyyyyyyyy]

For farming Portation Orb Fragment more conveniently. Otherwise we just have to walk along way when we want to supply Deconstruction Staff.

[Jenny 05 Justic]

 I don't think Klei is unwilling to do this — it's more likely that the Sanctum labyrinth's code is just incredibly complex, and this area isn't something you can simply go in and out of. The entire Sanctum is divided into the Foyer (the room you drop into from the big sinkhole, which has the hole where you can tie a rope) and the labyrinth zone. The way the labyrinth zone is implemented isn't like any terrain we've seen before — it's always in the same position on the map, but the terrain automatically morphs based on the player's interactions inside the labyrinth. The only entrance is through the signpost in the Foyer that teleports you into the labyrinth. When you enter the labyrinth and reach the second layer, any other players coming in from the Foyer will also skip the first layer and arrive directly at the second layer — because in reality there is only one room. To make this process feel plausible, everything is wrapped up as the Sanctum's spatial magic. If a rope could take you directly to the Key Room, then consider this scenario: Player A is in the middle of the labyrinth, and Player B tries to use the rope to enter the Key Room — at that moment, the Key Room literally doesn't exist. The reason you can enter the occupied labyrinth from the entrance via the signpost is because a one-way Foyer entrance was deliberately set up. Klei clearly hasn't cracked this complex labyrinth problem yet, so they have to be conservative about allowing entry and exit from the Key Room.

Of course, that doesn't mean there's no solution. Klei could consider placing a new repairable signpost inside the Key Room, allowing players who've completed it once to teleport directly in from the first layer of the labyrinth. That way they could keep the Foyer as the sole entry point while skipping the labyrinth's long, unskippable travel distance.

Edited June 9 by Jenny 05 Justic