The basic idea of the mod is, fog grows back instead of staying uncovered the entire game. This forces the user to not only have a wide empire but also a good network of scouts to re-explore territory.
1) Fog could grow back and hide the map, making civs and barbarians feel scarier. The probability for the fog to grow depends on the exploration-type techs you have researched. (Optics, Compass, Astronomy, etc).
2) Fog stops growing after Satellites Tech is researched ( by default).
3) Forts built by you, block fog from growing. Requires Community Patch to work. This makes Roman Legions unique ability useful.
4) The radius of uncovered plots vary depending upon defensive buildings built in that city. Wall and castle, each reduce it by 1.
5) If the AI builds defensive wonders like Great Wall, and Great Firewall, their entire land is enveloped in fog.
6) Most features mentioned above can be tweaked, or turned off. Look at Discussion Page for instructions and all available settings.
1) Community Patch by Gazebo
Used for implementing some features. Highly recommended, but the mod will still work if you don't download this, only some features will stop working.
(Does not require Community Balance Patch)
2) JFD's Exploration Continued Expanded
1) Disabled the code for fort and citadel sight promotion, because it would cause random crashes. I will push another update, once I figure out the reason behind it
1) Fixed bugs related promotions given by forts and citadels.
2) The radius of uncovered plots around cities depends on the defensive buildings built by that city.
3) Defensive wonders (Great Wall, and Great Firewall), completely envelop the country in fog (in respect of other players)
4) Tweaked the probability algorithm so that, as you discover more area, there is more varied "fogging". To put it simply fog grow will be more varied.
5) Added a few more settings, in the script.
1) Fixed a bug where forts would give dead units promotion and game would crash.
1) This mod no longer requires Community Patch to run, but some features might require it to work properly.
2) The fog now has a probability to grow. This probability decreases as you research exploration techs like Optics, Compass, Astronomy, etc.
3) Forts, that you built, will stop fog from growing. This feature requires Community Patch.
4) There is now a fully flushed out settings panel within the FogScript, where you can tweak almost anything within this mod. From what types of plot to fog, probability of fog (related to techs), number of plots to fog, etc. I highly recommend navigating to Core/LUA/GFOW_FogScript.lua, and tweaking these settings. There are a lot of them.
5) Removed "Reveal Map" goody , for obvious reasons.
6) Forts and citadels provide units extra sight. Special thanks to @zArkham4269 for suggesting this.
7) Fixed bug, where resource icon remains, even if the fog rolls over it. There is still a setting within the script that allows you to re-enable this.
Growing Fog of War v4.1 2016-10-05
Growing Fog of War v4.1