There are eighteen fortifications in total, or six per alliance:
- For the Aldmeri Dominion: Castle Alessia, Castle Black Boot, Castle Bloodmayne, Castle Brindle, Castle Faregyl, and Castle Roebeck.
- For the Daggerfall Covenant: Fort Aleswell, Fort Ash, Fort Dragonclaw, Fort Glademist, Fort Rayles, and Fort Warden.
- For the Ebonheart Pact: Arrius Keep, Blue Road Keep, Chalman Keep, Drakelowe Keep, Kingscrest Keep, and Farragut Keep.
There are also 3 outposts, or one per alliance:
- Nikel Outpost for the Aldmeri Dominion.
- Bleakers' Outpost for the Daggerfall Covenant.
- Sejanus Outpost for the Ebonheart Pact.
There are three types of fortifications:
- Elder Scroll Gate locking fortifications: these control Elder Scroll Gates, and without capturing them the Elder Scroll Temples are inaccessible to enemy players. There are two secondary and one primary Gate locking fortifications, as long the primary is held neither Gate will open, and the other two lock the Gate they are near so long as they are held by their alliance.
- For the Dominion the primary is Castle Faregyl, and the secondaries are Castle Black Boot for the Gate of Altadoon and Castle Bloodmayne for the Gate of Mnem.
- For the Covenant the primary is Fort Glademist, and the secondaries Fort Warden for the Gate of Ni-Mohk and Fort Rayles for the Gate of Alma Ruma.
- For the Pact the primary is Arrius Keep, and the secondaries are Kingscrest Keep for the Gate of Chim and Farragut Keep for the Gate of Ghartok.
- Emperor fortifications: if all six of these are captured by one alliance, the highest-ranked player on the leaderboard from that alliance is crowned Emperor, giving a +5 health bonus per level to each player in their alliance as well as the Emperor skill line and passive bonuses to themselves. These are only removed if the alliance loses control of all six Emperor keeps.
- For the Dominion these are Castles Alessia and Roebeck.
- For the Covenant these are Forts Ash and Aleswell.
- For the Pact these are Chalman and Blue Road Keeps.
- Outlying fortifications: these are far off the beaten path, located at the very edges of the map, and only serve to gain points and maintain the Home Keep Bonus.
- For the Dominion it is Castle Brindle.
- For the Covenant it is Fort Dragonclaw.
- For the Pact it is Drakelowe Keep.
Outposts are smaller structures, with only one wall protecting the inner flags. Outposts can be travelled to using the Transitus Network, but not travelled from. Players also cannot respawn at outposts. They do not count towards any of the Home Keep or Enemy Keep Bonuses.
Attackers must occupy two flagged locations within a fortification for a period of time in order to gain control of it. Utilizing siege weapons, every inner and outer wall, and the fortifications' doors, can be destroyed. Guards appear once a fortifications is claimed, although the damage that the structure has sustained won't be repaired instantly.
Each fortification is surrounded by three resource structures, within 60 seconds of travel time on foot, which control specific upgrades for it. Farms upgrade guards by giving them better abilities, mines upgrade walls, and lumber mills upgrade the fortification’s doors. In addition to walls and doors gaining more hit points, there are also some visual upgrades. All of these upgrades occur over time while the same Alliance owns the resources and the fortification. There are capture banners at each resource, and resources are captured independently of fortifications.
When a fortification is under attack, everyone in the zone will see an icon on the map that indicates the fortification's assault status once a section of its wall is damaged to 50%. Fortifications in Cyrodiil are linked together in a transit line. If an Alliance holds several linked fortifications, its members can fast-travel from one to another, unless that fortification is under attack. Masonry and woodworking kits can be purchased to help repair a fortification's damaged gates and walls more quickly. Alliance wide bonuses are also awarded for taking and maintaining the territory of fortifications, and these are applied in Cyrodiil and Alliance territories outside the province.
If an alliance control its six home fortifications, it earns the Home Keep Bonus, which gives a 5% boost to experience, alliance points, and gold earned. After an alliance controls its six home fortifications each fortification they capture after that provides the Enemy Keep Bonus, which provides the same boost to the Home Keep Bonus, but scales depending on how many keeps are owned, and at Enemy Keep Bonus II and up also increases Weapon and Spell Criticals. This goes up to a maximum of Enemy Keep Bonus IX. However, if the alliance loses even a single home fortification it loses both the Home Keep and Enemy Keep bonuses, even if they control all 17 other fortifications.
- ↑ 1.0 1.1 December 20, 2013. The Elder Scrolls Online Creating ESO: Cyrodiil’s Keeps
- ↑ 2.0 2.1 2.2 December 23, 2013. The Elder Scrolls Online Ask Us Anything: Cyrodiil
- ↑ September 9, 2013. The Elder Scrolls Online Ask Us Anything: Variety Pack 7
- ↑ June 28, 2013. The Elder Scrolls Online Support Will there be any fast travel between keeps...
- ↑ August 24, 2013. Teso Elite ESO Interview with Maria Aliprando