A few people as of late have stated they don't know exactly what to do in the end game, I figured that I may as well start a topic on my strategies for the late game, which unlike most of my strategy topics will actually be on the strategy, and not tactics of the situation.
So let us begin with an all too common scenario...
Note: All strategies are based on the assumption all other players are at least competent, of at least minimal intelligence, and are playing more or less to win.
Note: These strategies are to get you to a position to win, not to tell you when you're in a position to win and how to win from there.
Three Powers
As we all know when there are three powers left they generally tend to go after first the largest, and second the biggest threat.
Largest - When you're the largest in a game with three powers left you are going to be teamed, it's not a matter of if it's a matter of when. The longer the wait the worse your odds are if your income is less then the combined income of the other players. When the war starts, find a player who's attacking an area you need the least and is closest to largest, fight them less but still fight, fight the other player harder, when the first is largest point out that they are and that the two of you need to team that player.
Non Largest - When you become the largest you will most likely be teamed, so when the war starts fight the largest, but don't expend too much of your gold, you need the other players to focus on each other more than on you. When you feel you have enough of an advantage and can get land from the largest for the least amount of gold it's time to strike. Good Luck.
Four Powers
Four Power games generally turn into two 1v1 wars, and generally then turn into a Three Power game or a Two Power game.
Large Power - If you're a large power you'll generally attack a smaller power, in this case the other large power generally attacks the other smaller player, and no matter how many strategies get you from point A to point B point B will always be that you must kill your target first. If you do not and you need to fight the other large player immediately to win you will have to truce the small nation and go into the Three Power game it's just become, only you'll have strained relations with the small power, to say the least.
Small Power - A large power will most likely attack you, you must survive this war, if you do this successfully you're in a tough spot, the large nation near you will most likely still want to kill you, and you'll be in the toughest position of all, keeping the balance between the large powers while slowly growing. That is all the more difficult because one mistake and the others will kill you.
PS. If you have any other scenarios you need help with post them in this topic and I'll try to help.