Avatar Space (認知外空間) is an extra dimension of the game that exists outside of the perception of normal users, but parallel to and in direct interaction with the rest of The World R:2. Avatars exist in this space, and it can only be seen by Epitaph Users, as it applies the rule that only Epitaph Users can see an Avatar. Normal PCs can only see it if they are infected with AIDA or through the Serpent of Lore. Hackers are also be able to see them by watching the datastream, similar to the serpent of lore.
Avatar Space in the .hack//G.U. Novels
In the .hack//G.U. Novels, when two Avatars touch, an Avatar Space (巫器空間) is formed. Avatar Space is a white space where the thoughts and wills of the users blend. During Haseo's battle with Endrance, an Avatar Space is formed and Haseo sees some of Endrance's memories.