Online:Subzones

Subzones are sections of the map smaller than the full Zones, but larger than cities or other settlements. The content within a single subzone region was originally designed for a specific level bracket of players, spanning approximately 3 levels. During the development cycle of ESO, the concept of subzones as a distinct gameplay feature has slowly declined, and as of Update 12, there are only a few remnants of the system left. Prior to Update 9, level-appropriate Subzones were listed in the Grouping Tools interface under the "World" heading when searching for a party to quest with, but this was removed in an overhaul of the Grouping Tool. The level brackets themselves were removed in the One Tamriel update, which opened up the whole game world to players of any level.

Each major Zone which released prior to Morrowind can be divided into three subzones, and in early versions of the beta, these had their own in-game maps. The graphics for these maps, which had a different visual style to those which were eventually present at the game's release, still existed in the game data initially, but were subsequently removed. However, the names of the subzones are still used in some places, including location names and quest dialogue, and there are still loose regional divisions within each Zone that correspond to the subzones. For example, each subzone is contained entirely within the borders of a traditional province, unlike some of the larger zones, and each subzone has a Dolmen which shares its name (except in Coldharbour, which of course has no Dolmens). Additionally, exactly two Delves and exactly two Group Bosses can be found in each subzone, and each subzone also has its own major questline, and an Achievement awarded for completing it. While the subzone questlines may be related, and form part of the Zone's overall questline, they are often distinctly separate, and some can even be done out of order or concurrently (which may seem odd, as many involve the same NPCs, who may be found in both locations simultaneously). As a significantly larger zone, Cyrodiil functions slightly differently, but can still be divided into three (unnamed) subzones based on the territory initially controlled by each Alliance in the Alliance War. Each territory is then further divided into a number of named geographical regions; Dolmens in Cyrodiil are named based on these regions, and there are three Dolmens per subzone (not counting Bruma). Cyrodiil also has exactly six Delves per subzone (rather than two), and exactly six marked Ayleid Ruins (which serve no functional purpose).

Craglorn was the first zone released which did not fit smoothly into the three-subzone format, as it was released in just two parts, namely Lower and Upper Craglorn. However, the questing and geography of Lower Craglorn still loosely corresponded to two subzones, with a clear division between the content of the (then unnamed) eastern and western areas, and promotional material at the release of Upper Craglorn referred to that area as the "third region of Craglorn", rather than the second. Each Craglorn subzone initially contained six Group Delves and five Group Events (which were eventually partially repurposed into standard Delves and Group Bosses, respectively). When Wrothgar was released a year later, it had no functional subzones, as it was the first zone to make use of the Battle Leveling system and feature a questline which spanned the entire zone. It was still geographically divided into three distinct regions, but the strict placement of two Delves and two Group Bosses per region was no longer present. With the launch of Morrowind, featuring the Vvardenfell zone, the subzone concept appears to be completely abandoned, as the only regional divisions on the island are recalled from its previous appearance, while many questlines span the entire island and are not confined to particular areas.

Even after the discontinuation of subzones, many zones can still be divided into multiple Regions, with the developers stating on ESO Live (VOD) that Western Skyrim was designed with three different climate zones in mind, while other zones often have three biomes used by NPCs to describe locations.
 
Aldmeri Dominion
Auridon
 (Levels 5–7)
 (Levels 7–12)
 (Levels 12–15)

Grahtwood
 (Levels 16–18)
 (Levels 19–21)
 (Levels 22–23)

Greenshade
 (Levels 24–26)
 (Levels 27–29)
 (Levels 30–31)

Malabal Tor
 (Levels 32–34)
 (Levels 34–35)
 (Levels 36–37)

Reaper's March
 (Levels 37–40)
 (Levels 40–41)
 (Levels 41–43)

Daggerfall Covenant
Glenumbra
 (Levels 5–8)
 (Levels 9–12)
 (Levels 13–15)

Stormhaven
 (Levels 16–19)
 (Levels 19–21)
 (Levels 20–24)

Rivenspire
 (Levels 24–26)
 (Levels 26–28)
 (Levels 29–31)

Alik'r Desert
 (Levels 31–32)
 (Levels 32–34)
 (Levels 35–37)

Bangkorai
 (Levels 37–38)
 (Levels 39–40)
 (Levels 41–42)

Ebonheart Pact
Stonefalls
 (Levels 5–11)
 (Levels 11–13)
 (Levels 13–15)

Deshaan
 (Levels 16–18)
 (Levels 18–21)
 (Levels 21–23)

Shadowfen
 (Levels 24–26)
 (Levels 27–29)
 (Levels 30–31)

Eastmarch
 (Levels 32–33)
 (Levels 34–35)
 (Levels 36–37)

The Rift
 (Levels 38–39)
 (Levels 39–41)
 (Levels 41–43)

Neutral Zones
Coldharbour
 (Levels 44–46)
 (Levels 46–48)
 (Levels 48–50)

Craglorn
 ( )


 ( )

Cyrodiil