I have been playing on monarch, huge map, max AI's, all other settings random. I find I am usually facing only one primary AI foe by the time the industrial age starts.
I recently started using a new tactic; forcing my primary AI foe to change goverments. On Monarch (not sure about other levels) the AI will go for democracy if it's not at war. This can work to your advantage.
Treat primary foe as a rogue state (there's a good thread for this strategy in this section) early in the game. Initiate a war or three with the primary foe. Get him into communisim and facism and keep him there until the mordern age starts. This usually requires you stay in communism also. Make peace at the begining of the modern age.
Be sure you have at least an embassy and hopefully a spy in the primary foe's capital. You'll need to keep a close eye on him.
When the primary foe makes peace he will switch to democracy. Stay in communism (or facism). He will lose several turns to anarchy. Build your army, improve your infra-structure and research
You move forward while he stands still for several turns.
As soon as he makes the conversion to democracy he will begin to retool his economy and army. Democracy will leave him unable to support the army your rogue state has required him to build up. My experince is the AI will sacrifice good units. My experince is offensive go on the disband list. I am not 100% certain of this, someone with more time playing can give more details on if the AI will disband and what units. My experince is just from spying and glancing at the military advisor screen. It *seems* to me the AI will disband it's most expensive offensive units. By this time those units are tanks
Give the AI a turn or two in democracy.
During the turn or two the AI is disbanding offensive units gather and position your invasion force. At the begining of your turn taunt the primary foe into declaring war. Make sure he declares war. Don't invade him. Make him start the war. Once he does pour your army into his territory. It's very important to cause as mush damage as possible in that first turn. Take as least a city or two. Destroy as many units as you can, even if they aren't strategic units. Also cut off as many luxes and resources as you can. The point is to force the AI to switch out of democracy. The combination of declaring war and losing a large number of units and luxes will cause a quick switch back to communism or facism.
If you do enough damage the AI will initiate the switch back in one turn. So you'll have several more turns to move past him in research plus his production will be shut down while you roll through his defenses. By the time he comes out of anarchy you should have the war in hand. Again he stands still while you move forward. This time not only is he standing still but you are beating on him like a bad dog at the same time.
This has worked well for me for spaceship victories. Enjoy
I recently started using a new tactic; forcing my primary AI foe to change goverments. On Monarch (not sure about other levels) the AI will go for democracy if it's not at war. This can work to your advantage.
Treat primary foe as a rogue state (there's a good thread for this strategy in this section) early in the game. Initiate a war or three with the primary foe. Get him into communisim and facism and keep him there until the mordern age starts. This usually requires you stay in communism also. Make peace at the begining of the modern age.
Be sure you have at least an embassy and hopefully a spy in the primary foe's capital. You'll need to keep a close eye on him.
When the primary foe makes peace he will switch to democracy. Stay in communism (or facism). He will lose several turns to anarchy. Build your army, improve your infra-structure and research

As soon as he makes the conversion to democracy he will begin to retool his economy and army. Democracy will leave him unable to support the army your rogue state has required him to build up. My experince is the AI will sacrifice good units. My experince is offensive go on the disband list. I am not 100% certain of this, someone with more time playing can give more details on if the AI will disband and what units. My experince is just from spying and glancing at the military advisor screen. It *seems* to me the AI will disband it's most expensive offensive units. By this time those units are tanks

During the turn or two the AI is disbanding offensive units gather and position your invasion force. At the begining of your turn taunt the primary foe into declaring war. Make sure he declares war. Don't invade him. Make him start the war. Once he does pour your army into his territory. It's very important to cause as mush damage as possible in that first turn. Take as least a city or two. Destroy as many units as you can, even if they aren't strategic units. Also cut off as many luxes and resources as you can. The point is to force the AI to switch out of democracy. The combination of declaring war and losing a large number of units and luxes will cause a quick switch back to communism or facism.
If you do enough damage the AI will initiate the switch back in one turn. So you'll have several more turns to move past him in research plus his production will be shut down while you roll through his defenses. By the time he comes out of anarchy you should have the war in hand. Again he stands still while you move forward. This time not only is he standing still but you are beating on him like a bad dog at the same time.
This has worked well for me for spaceship victories. Enjoy
