Fatal Years is a mod for Revolution Under Siege. Its 2 main features are better gameplay thanks to a reworking of player options and an improved AI. Fatal Years is a game currently played by me,among others, and that's certainly its greatest strength, being designed not to be bought, downloaded or admired, just played.
The only scenario currently modded is the Great Campaign from June 1918.Only supported in English language.
All three factions (Red, Southern and Siberian Whites) are playable.
Fatal Years may be played in PBEM or against AI.
Best options for AI are:

Note: the +2 bonus for Fog of war may be discarded or reduced to +1. The AI will remain a worthy opponent.
Fatal Years rules are available here, in pdf format:
http://moddercorner.com
Among the main changes, the option system has been reworked to give player choice between enforcing a land reform or stick with the historical doctrine made by each side, more diplomatic options, the possibility to recruit units of opposing factions, and an Allied Intervention Level determining the size and the actions of Western Allied Units during the Civil War. Siberian Whites may now succeed to take control of the Southern White faction and iobtain, under severe conditions, Japanese military help.
Beyond the 3 main playable factions, the Grand Campaign features several minor factions, Ai driven only: Ukrainians, Poles, Anarchists, Freikorps and Greens. Don't neglect them, AI being rather smart. Red player may take control of the Anarchist units for sme turns
please do not neglect Clovis' mod...it really makes you actually want to play the game, and think about strategy for the Reds.
FY is worth every second you spend to install it.
the more I play this the more I become convinced that RUS is one of the best strategy games I have ever played... and I have played many since the mid 80's. The AI in this mod is at level with Sid Meier's best efforts.
Note for Russian players: I've seen some of you are considering greatly Fatal Years. Thanks first. Please don't forget I'm French, not Russian. I've tried to be as fair and as historical than possible between the different sides. Certainly there are errors or misconceptions. Don't waver to post your critics, I will read them and if the engine allows I will modify Fatal Years.
Last point: I've seen some of you are using pirated version of RUS. I'm not a moralist, and to say the least I've no real praise for SEPRUS patch policy and for the game design ideas put in the official campaign. BUT they deserve the price of their work and piracy is the best way to destroy any new game of this sort. So, if ever I get the feeling someone uses a pirated version of RUS, I will just ignore him. I will never support pirated games.
Fatal Years is available here:
http://moddercorner.com
A movie about install process can be viewed here:
http://youtube.com/watch?v=BtU0m_oZXcw&feature=related
This mod incorporates leaders portraits available on official forum and done by Nikel.
Have been added too Keke's files modifying weather files to raise probability of blizzard during winter.
This game has benefitted from the feedback of many, who have demonstrated being themselves REAL playtesters, very different to some guys writing endlessly on their pet ideas about the game without finding any bugs. There are some indeed acting like this, but fortunately not here ( in any ways, I wouldn't listen them, some recent releases having demonstrated how much damaging they may reveal, even for a great engine when the scenario work is messed by their proposals and lack of any king of real competence...)
Enjoy, post remarks and AAR