FORTS in Beyond The Sword
Everything there is to know about forts in BtS!
This article is intended as a reference for anything concerning forts. There are so many things to know about forts; many players probably do not know all of the following...
For the moment, I have bolded the points I believe are lesser known or worth noting.
} Forts provide +25% defensive bonus. This adds to any other defense modifiers on the tile. For example, a fort built on a hill forest has a +100% defense modifier (+25% from hill, +50% from forest, +25% from fort).
} Forts can be built on top of any terrain or overlay (except oasis, strangely), but they cannot exist on a tile with another improvement simultaneously (except roads of course). A fort therefore does not remove a forest or jungle. Forts obviously can't be built on water, peaks or cities.
} Forts require the tech Mathematics (not Construction) before your wokers can build them.
} Forts require 10 worker turns to build (15 on epic, 38 turns on marathon, 7 turns on quick). Forts can only be built in your territory and in neutral (ie. outside all borders) territory - never in foreign territory.
} City Garrison promotions are used by units defending forts.
} City Raider promotions are used against units in forts. (hey it's only fair
)
} Forts connect resources when they are in your borders and connected to the necessary roads/rivers. In terms of connecting up the resource forts are equivalent to the resource-specific tile improvement, but they do not provide the specific yield bonus for that tile.
} Forts with roads function as nodes linking road-networks to coast-networks. This is especially useful for hooking up resources on small offshore islands which aren't worth an extra city. The fort itself can also be in neutral territory to establish the connection. These forts can also connect coastal trade networks which are split by impassable ice. (thanks DanF771)
} Forts in home territory and neutral territory heal units at 20HP per turn, just as cities do. Normally units in home territory get 15HP per turn, and units in neutral territory get 10HP per turn.
} Forts can be used as canals. Any fort in your culture boders, or city, which touches a water tile (inland lake or coast) can have naval units pass through it. Forts in neutral territory can not be used as canals. For a civ that has open borders with you, their naval units cannot use your forts but they can use your cities.
Additional note: Masters can always use a vassal's fort canals, but vassals can only use the master's fort canals when they have open borders. Strangely, your privateers cannot be attacked by your vassals if they are in your forts, as it seems the vassal cannot see the privateers. (thanks DanF5771)
Another note, by way of example, quoted from UncleJJ (thanks): "I've built a line of forts 8 wide across the southern end of my continent when it was blocked by ice flows. Submarines could get through and my workers had nothing better to do so I built this "Sothern Passage". Each fort had to be either next to water or next to ice (which counts as water for this purpose) and also needs to be inside your own culture for the ships to pass. This was quite useful, in that game, for shifting ships from one side of my continent to the other, and massing my fleets, rather than a long trip around the other continent as mine was blocked at the northern and southern ends."
} Up to four air units can be based in a fort.
} Paratroopers can paradrop from forts in friendly territory. Friendly territory only includes your territory and master/vassal territory. (thanks DanF5771)
} If a naval or air unit is on a tile when it becomes occupied by an enemy land unit the naval or air unit is destroyed, so be careful!
} Tactical nukes and cruise missiles can be rebased to forts, and launched from forts. They can also be loaded onto Submarines and Missile Cruisers from forts (the ship must be on the same tile - not an adjacent tile!). Missiles are also destroyed if an enemy land unit takes the fort.
} Units with no movement points left can be loaded onto ships from forts (just like cities). Missiles can be rebased to forts and loaded on the same turn too.
} Forts in enemy territory do not provide any benefit to you, not even the +25% defense bonus. To you, the enemy fort may as well not exist unless the enemy is using it! Equally, forts in your territory cannot be used by your enemies. Obviously, a fort in neutral territory benefits whoever controls it.
} Siege units in forts cannot be flanked by mounted units with Flanking. In this sense, forts behave like cities, acting as safer places for you to store your siege units.
} Units that have inherent defense bonuses for cities (eg. archers and longbows) use these bonuses in forts too.
} The +25% defensive bonus of forts cannot be bombarded. At times this can make them easier to defend than a city!
} Forts can be destroyed by spies. All improvements cost the same EPs when sabotaged with a spy. (thanks DanF5771)
} Forts can be destroyed by units running the Air Bomb mission (available to Bombers, Stealth Bombers and Guided Missiles). Forts come with iAirBombDefense = 20 (like forest preserves; mines, quarries, wells and offshore platforms have 10; all others 5). (thanks Tephros and DanF5771)
} If a fort is destroyed (eg. you could pillage your own fort or an enemy air unit might bomb it), air units are transferred to the nearest city or fort in your borders that has space available. If there is no space anywhere the air units are destroyed! Naval units will be expelled to the water. (thanks Tephros). Missile units will also be transferred to the nearest city or fort in your borders (there is no stack limit on missiles).
How can you use forts?
Please reply to this thread if you know other uses for them. So far I have only included things which may not be thought of. Things like making a tile easier to defend are obvious at this stage, but ways you could use that advantage could be elaborated on, if you want to, and I will put your comments here.
} Connecting up resources outside of city BFCs.
} Creating canals for your ships to pass through. It can be a big time saver, allowing fewer ships to defend more area on both sides of the canal.
} Since no other civ can put their naval units in your forts, you can use them as safe zones for privateers! The civs who have open borders with you can't touch them, so you can pick off the occasional caravel that comes into range etc.
} Forts can be "prebuilt". What I mean by that is that if it takes 15 worker turns to build it, and you put in 14 worker turns, the fort is nearly built but you can leave a better improvement on the tile. For example if you have a happiness resource on a tile that could be used for a canal, and you only need that canal very occasionally, you could build that fort only when you need to use it and rebuild the improvement when you're not using it. This requires you to have the workers available to do it.
Additional note (thanks Tephros): About the pre-building. Sometimes with spies or planes the enemy will try to destroy your strategic resource improvements. If this happens to be your only oil source, it can halt progress on important units. If you have an oil source within your big fat cross, build the well but then prebuild a fort so that if the well is destroyed you can immediately get a worker there and complete the prebuilt fort so that there is no lapse in access. For oil outside of a big fat cross, you can prebuild the well over the fort. In both cases, be careful not to actually complete the prebuild though. Also a good idea to keep a spy and interception-promoted SAM on those tiles.
} Loading units onto transports, if you're ever in a situation where your units are having to stop on the tile adjacent to your ship, you could put a fort there and get an extra turn of movement with the ship.
} Forts can be used to form canals 2 tiles wide. This is because each fort only needs to be touching 1 water tile. Technically you can form fort canals as long as you want but each fort must be touching a water tile. A fort chain may make a a canal 3 tiles wide, for example, if there is an inland lake touching the middle fort. (thanks Tephros)
} If your air and naval units stationed in a fort are in serious danger, you can self-pillage the fort with one of your (last) land units to trigger an auto-rebase of those units to a safer place even when they have no movement points left. (thanks DanF5771)
Everything there is to know about forts in BtS!
This article is intended as a reference for anything concerning forts. There are so many things to know about forts; many players probably do not know all of the following...
For the moment, I have bolded the points I believe are lesser known or worth noting.
} Forts provide +25% defensive bonus. This adds to any other defense modifiers on the tile. For example, a fort built on a hill forest has a +100% defense modifier (+25% from hill, +50% from forest, +25% from fort).
} Forts can be built on top of any terrain or overlay (except oasis, strangely), but they cannot exist on a tile with another improvement simultaneously (except roads of course). A fort therefore does not remove a forest or jungle. Forts obviously can't be built on water, peaks or cities.
} Forts require the tech Mathematics (not Construction) before your wokers can build them.
} Forts require 10 worker turns to build (15 on epic, 38 turns on marathon, 7 turns on quick). Forts can only be built in your territory and in neutral (ie. outside all borders) territory - never in foreign territory.
} City Garrison promotions are used by units defending forts.
} City Raider promotions are used against units in forts. (hey it's only fair
)} Forts connect resources when they are in your borders and connected to the necessary roads/rivers. In terms of connecting up the resource forts are equivalent to the resource-specific tile improvement, but they do not provide the specific yield bonus for that tile.
} Forts with roads function as nodes linking road-networks to coast-networks. This is especially useful for hooking up resources on small offshore islands which aren't worth an extra city. The fort itself can also be in neutral territory to establish the connection. These forts can also connect coastal trade networks which are split by impassable ice. (thanks DanF771)
} Forts in home territory and neutral territory heal units at 20HP per turn, just as cities do. Normally units in home territory get 15HP per turn, and units in neutral territory get 10HP per turn.
} Forts can be used as canals. Any fort in your culture boders, or city, which touches a water tile (inland lake or coast) can have naval units pass through it. Forts in neutral territory can not be used as canals. For a civ that has open borders with you, their naval units cannot use your forts but they can use your cities.
Additional note: Masters can always use a vassal's fort canals, but vassals can only use the master's fort canals when they have open borders. Strangely, your privateers cannot be attacked by your vassals if they are in your forts, as it seems the vassal cannot see the privateers. (thanks DanF5771)
Another note, by way of example, quoted from UncleJJ (thanks): "I've built a line of forts 8 wide across the southern end of my continent when it was blocked by ice flows. Submarines could get through and my workers had nothing better to do so I built this "Sothern Passage". Each fort had to be either next to water or next to ice (which counts as water for this purpose) and also needs to be inside your own culture for the ships to pass. This was quite useful, in that game, for shifting ships from one side of my continent to the other, and massing my fleets, rather than a long trip around the other continent as mine was blocked at the northern and southern ends."
} Up to four air units can be based in a fort.
} Paratroopers can paradrop from forts in friendly territory. Friendly territory only includes your territory and master/vassal territory. (thanks DanF5771)
} If a naval or air unit is on a tile when it becomes occupied by an enemy land unit the naval or air unit is destroyed, so be careful!
} Tactical nukes and cruise missiles can be rebased to forts, and launched from forts. They can also be loaded onto Submarines and Missile Cruisers from forts (the ship must be on the same tile - not an adjacent tile!). Missiles are also destroyed if an enemy land unit takes the fort.
} Units with no movement points left can be loaded onto ships from forts (just like cities). Missiles can be rebased to forts and loaded on the same turn too.
} Forts in enemy territory do not provide any benefit to you, not even the +25% defense bonus. To you, the enemy fort may as well not exist unless the enemy is using it! Equally, forts in your territory cannot be used by your enemies. Obviously, a fort in neutral territory benefits whoever controls it.
} Siege units in forts cannot be flanked by mounted units with Flanking. In this sense, forts behave like cities, acting as safer places for you to store your siege units.
} Units that have inherent defense bonuses for cities (eg. archers and longbows) use these bonuses in forts too.
} The +25% defensive bonus of forts cannot be bombarded. At times this can make them easier to defend than a city!
} Forts can be destroyed by spies. All improvements cost the same EPs when sabotaged with a spy. (thanks DanF5771)
} Forts can be destroyed by units running the Air Bomb mission (available to Bombers, Stealth Bombers and Guided Missiles). Forts come with iAirBombDefense = 20 (like forest preserves; mines, quarries, wells and offshore platforms have 10; all others 5). (thanks Tephros and DanF5771)
} If a fort is destroyed (eg. you could pillage your own fort or an enemy air unit might bomb it), air units are transferred to the nearest city or fort in your borders that has space available. If there is no space anywhere the air units are destroyed! Naval units will be expelled to the water. (thanks Tephros). Missile units will also be transferred to the nearest city or fort in your borders (there is no stack limit on missiles).
How can you use forts?
Please reply to this thread if you know other uses for them. So far I have only included things which may not be thought of. Things like making a tile easier to defend are obvious at this stage, but ways you could use that advantage could be elaborated on, if you want to, and I will put your comments here.
} Connecting up resources outside of city BFCs.
} Creating canals for your ships to pass through. It can be a big time saver, allowing fewer ships to defend more area on both sides of the canal.
} Since no other civ can put their naval units in your forts, you can use them as safe zones for privateers! The civs who have open borders with you can't touch them, so you can pick off the occasional caravel that comes into range etc.
} Forts can be "prebuilt". What I mean by that is that if it takes 15 worker turns to build it, and you put in 14 worker turns, the fort is nearly built but you can leave a better improvement on the tile. For example if you have a happiness resource on a tile that could be used for a canal, and you only need that canal very occasionally, you could build that fort only when you need to use it and rebuild the improvement when you're not using it. This requires you to have the workers available to do it.
Additional note (thanks Tephros): About the pre-building. Sometimes with spies or planes the enemy will try to destroy your strategic resource improvements. If this happens to be your only oil source, it can halt progress on important units. If you have an oil source within your big fat cross, build the well but then prebuild a fort so that if the well is destroyed you can immediately get a worker there and complete the prebuilt fort so that there is no lapse in access. For oil outside of a big fat cross, you can prebuild the well over the fort. In both cases, be careful not to actually complete the prebuild though. Also a good idea to keep a spy and interception-promoted SAM on those tiles.
} Loading units onto transports, if you're ever in a situation where your units are having to stop on the tile adjacent to your ship, you could put a fort there and get an extra turn of movement with the ship.
} Forts can be used to form canals 2 tiles wide. This is because each fort only needs to be touching 1 water tile. Technically you can form fort canals as long as you want but each fort must be touching a water tile. A fort chain may make a a canal 3 tiles wide, for example, if there is an inland lake touching the middle fort. (thanks Tephros)
} If your air and naval units stationed in a fort are in serious danger, you can self-pillage the fort with one of your (last) land units to trigger an auto-rebase of those units to a safer place even when they have no movement points left. (thanks DanF5771)
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