Key 8
Spoilers Ahead
This page contains spoilers for Gallery. View at your own discretion.
Key 8 is a unique special key. Found in the Gallery and claiming to unlock the Puzzle Room that follows in the Room Directory, Key 8 has a clear connection to Room 8, but its description doesn't clarify where or how it should be used.
How to obtain
Key 8 is obtained in the Gallery. Once all four artworks have been successfully named, the second chest permanently opens and allows Key 8 to be picked up. Key 8 always spawns here, even if one or more copies of Key 8 are already held or are stored in Coat Check.
[Found Floorplan: Lost & Found] Starting on Day 365, Key 8 will begin appearing in Lost & Found. Like most items, it cannot spawn if the item is already owned or spawned. See Lost & Found#Items for more information. This happens even if Gallery is still in the draft pool.
Usage
Key 8 appears in the menu of available special keys when trying to open a locked door. However, it generally will not fit.
Spoilers Within
This section contains spoilers for using Key 8.
Key 8's usage is similar to that of the Secret Garden Key, as it does not fit most locked doors but can be used on any locked door leading into a room on Rank 8. Using Key 8 in this manner will skip the entire floorplan-drawing process and immediately draft Room 8.
Room 8 will always be drafted from its south door if possible, as seen from its floorplan image, to match the view of the room provided by the Gallery. In the circumstances where this would result in the side door leading outside of the house, it is drafted from that door instead, resulting in the corner room pointing left instead of right. This is limited to drafting northwards from Rank 7 in the East Wing, and drafting southwards from Rank 9 in the West Wing.
With multiple copies of Key 8, multiple copies of Room 8 can be drafted.
Key 8 cannot be used on a Great Hall side door.
[Studio Addition: Vestibule] It can, however, be used on a Vestibule locked door, as long as that door leads into Rank 8 and there is no room already in the way. Prior to Patch 1.6, attempting to use Key 8 this way would softlock the game.
Spoilers Within
This section contains spoilers for a very lategame puzzle.
Key 8 is involved in the Family Core puzzle.
Puzzle answer spoiler: Key 8 can be used to open cabinet 053 in the Vault.
Additional information
Spoilers Within
This section contains spoilers for a hint for finding the usage.
The description of Trophy 8 provides a hint about how Room 8 can be found: "Solve the enigma of Room 8 on Rank 8."
Combined with the description of Key 8, it is natural to try using it on a door leading into Rank 8.