Fallout: New Vegas mod lets you play after beating the game
FPGE - Functional Post Game Ending is a mod that allows you to play after the final mission of the game and unlike other mods, FPGE makes your decisions count. The Mojave Desert will never be the same again and depending on who you sided with there will be different outcomes:
After two weeks, Hoover Dam is taken over by the respective faction and the fighting stops, the Kings will get eradicated by the Legion, if alive, the Brotherhood of Steel will take over Helios One and patrol the roads, and the Great Khans will evacuate their camp, taking everything with them. This is only a small portion of what can take place however, and there are a massive amount of things that change based on how you play.
The dialogue was also changed in-game to reflect the different endings, as you can see for example below:
"We'll show everyone that these are our new territories!" - NCR citizen. This is no longer shown should the NCR lose, why would they prattle on about this after they lose?
"We won't go quietly, the Legion can count on that" - NCR trooper. No longer shown should the Legion fail miserably, they wouldn't exactly need to worry about that after they win would they?
These are but a fraction of the changes made to the game and the modder, Kazopert, assures us there's a lot more to discover in game.
Players will need a copy of Fallout: New Vegas to use this mod and the mod can't be used with other "Continue after the ending" mods. Also FPGE doesn't have any effect on the game before the ending slides have taken place.