After having previously announced that 19 realms are now operating on a single layer, the WoW Classic devs stated on October 23 that 17 new servers are now no longer layered.
Update: On October 24, Blizzard stated that 4 new european servers were down to a single layer.
List of Affected Realms
Europe
English
- Dreadmist
- Flamelash
- Stonespine
German
- Transcendence
Americas
US East
- Atiesh
- Bigglesworth
- Blaumeux
- Grobbulus
- Myzrael
- Rattlegore
- Thunderfury
US West
- Benediction
- Bloodsail Buccaneers
- Kirtonos
- Kromcrush
- Mankrik
- Skeram
- Stalagg
- Sulfuras
- Westfall
Oceania
- Yojamba
What is Layering?
Layering is a technique which is similar to Sharding; it was present on all World of Warcraft servers. In essence, each server is comprised of several layers, and each layer contains the entirety of the world map.
When a character is created, it is automatically assigned to one of these layers and is not able to leave it unless Blizzard deactivates the entire Layering system.
It employs the use of several smaller servers inside a larger server to reduce lag, issues pertaining to creature respawns, etc.
This system is different from Sharding, as the latter only requires the use of layers for small sections of the map instead of the entire world being layered.
Players can leave layers by joining groups (effectively Realm Hopping).