zulu9812
The Newbie Nightmare
Let me share some observations with you. We've all been there: it's Emperor level, you're having trouble keeping up, a larger civ demands something from you, you tell 'em where to go, and BAM! you're at war and you've bitten off more than you can chew. One tactic I've come up with, a spin on the fighting retreat, is the sacrificial retreat.
Rule #1 - Initially, only fight in your own territory
This is a tactic dating back to the Roman Empire. The Legions would lure the enemy into Roman borders before engaging. Doing this had 3 advantages: the Romans knew the lay of the land better than their opponent, their opponent was a long way from home which can be demoralising, the Roman supply line was short, whilst the enemy's was long. But how can this be adapted to CivIII? Simple. Roads only work for the home civ. So you can outflank your opponent and even deny them the opportunity to engage. Their 1-move unit will move towards your stack of units and when they get close enough, your 3-move (or even 6-move) units can melt away. In this way, you can draw the enemy away from your cities. It should be noted that the AI will always go for your cities unless an easy target presents itself. They will not move away from their city-bound route in order to engage your 12-strong stack. Unescorted settlers and workers are good for this. Additonally, enemy units in your territory suffer from a limited radius of visibilty, whereas you don't. You can engage in hit & run attacks, literally melting back into the darkness.
For this part of the tactic, culture is your friend and it is best if there are more than 4 tiles between cities. Whilst AI units will always know exactly where your cities (even if officially they're not supposed to) the extra distance buys you time. Not only that, but pillaging won't do as much harm if not every tile is being worked. And make no mistake, the AI loves to pillage. Whilst pillaging buys you yet more time, it takes you 12 turns to replace a mine that only took one turn to destroy. Attacking in your own territory allows you to make quick strike, so do that. Lastly, your troops can fortify and heal: the enemy can fortify, but they can't heal. Not only that, but you have a shorter fall-back route to a place where your units can heal to full strength in one turn (i.e. a city with barracks).
Rule #2 - Shorten your battle-line
At the higher difficulty levels, the AI gets multiple bonues which will enable it to support more troops than you. Couple with the fact that we've already established that the enemy is stronger, and you will almost definitely be outnumbered. So you need to concentrate your forces. If you concentrate them in only certain cities, the AI will go after the lightly-defended ones, since they know your troop dispositions (another AI cheat). So you need to deploy in force to protect all cities, and still maintain a standing responce force. But how do you do that if you're already outnumbered, I here you cry? Simple, abandon some of your cities.
This is nowhere near as disasterous as it might sound. Firstly, you only abandon the cities (using the 'Abandon city' button on the city screen) that you were going to lightly defend, which were going to be captured anyway. Secondly, by doing so you deny your enemy territorial expansion, which is really what they're after in the first place. Thirdly, you deny the enemy a forward base of operations. If the enemy capture one of your cities, it means their troops only have to fall back a short distance to heal, which removes one of your advantages discussed above. Fourthly, you deny the enemy the added production power they would gain - this is vital, particularly in the Ancient and Middle ages, where units cost less.
Finally, if you have a bit of time before the enemy marches on your cities, rush-buy some workers. That way, abandoning cities isn't so much of a loss, and you can also have those workers rejoin the cities you're keeping. This will increase both their production power, and defense bonus if you can push them past size 6 and 12 with this.
Rule #3 - Gain allies!
Not just so they will attack your enemy, diverting their troops away from you, but also so the enemy won't form alliances against you! There is only so much outnumbering you can take...
Rule #4 - Show the enemy you can hurt them
The AI will come to the peace table eventually, but in order to broker a good deal you need to show the enemy that you can hurt them. Inevitably, this will mean a foray into enemy territory What type of unit to use depends on what era you are in. If it's the modern or industrial age the enemy territory will undoubtedly be covered in railroads and your force will be attacked before it even gets within striking distance of a city. In this case, fast units are essential. Even better are Marines, which can move from the sea to take a city in one turn, as opposed to tanks which will take at least two. In this case marines are more survivable than tanks, despite lower stats, because they spend less time out in the open. In it's the Ancient age, you don't really need to worry about being outmanouvered (the AI won't really use the tactics I've outlined) and you should go for swordsmen rather than horsemen. If it's the middle age, Knights or Cavalry every time.
I hope that helps some people out. I'm well aware that these tactics are by no means definitive, so feel free to chip in.
Finally, remember these (paraphrased) words of Winston Churchill:
"Let them have it. Avoid a fight if you can. But once battle is joined, by God let them have it"
Rule #1 - Initially, only fight in your own territory
This is a tactic dating back to the Roman Empire. The Legions would lure the enemy into Roman borders before engaging. Doing this had 3 advantages: the Romans knew the lay of the land better than their opponent, their opponent was a long way from home which can be demoralising, the Roman supply line was short, whilst the enemy's was long. But how can this be adapted to CivIII? Simple. Roads only work for the home civ. So you can outflank your opponent and even deny them the opportunity to engage. Their 1-move unit will move towards your stack of units and when they get close enough, your 3-move (or even 6-move) units can melt away. In this way, you can draw the enemy away from your cities. It should be noted that the AI will always go for your cities unless an easy target presents itself. They will not move away from their city-bound route in order to engage your 12-strong stack. Unescorted settlers and workers are good for this. Additonally, enemy units in your territory suffer from a limited radius of visibilty, whereas you don't. You can engage in hit & run attacks, literally melting back into the darkness.
For this part of the tactic, culture is your friend and it is best if there are more than 4 tiles between cities. Whilst AI units will always know exactly where your cities (even if officially they're not supposed to) the extra distance buys you time. Not only that, but pillaging won't do as much harm if not every tile is being worked. And make no mistake, the AI loves to pillage. Whilst pillaging buys you yet more time, it takes you 12 turns to replace a mine that only took one turn to destroy. Attacking in your own territory allows you to make quick strike, so do that. Lastly, your troops can fortify and heal: the enemy can fortify, but they can't heal. Not only that, but you have a shorter fall-back route to a place where your units can heal to full strength in one turn (i.e. a city with barracks).
Rule #2 - Shorten your battle-line
At the higher difficulty levels, the AI gets multiple bonues which will enable it to support more troops than you. Couple with the fact that we've already established that the enemy is stronger, and you will almost definitely be outnumbered. So you need to concentrate your forces. If you concentrate them in only certain cities, the AI will go after the lightly-defended ones, since they know your troop dispositions (another AI cheat). So you need to deploy in force to protect all cities, and still maintain a standing responce force. But how do you do that if you're already outnumbered, I here you cry? Simple, abandon some of your cities.
This is nowhere near as disasterous as it might sound. Firstly, you only abandon the cities (using the 'Abandon city' button on the city screen) that you were going to lightly defend, which were going to be captured anyway. Secondly, by doing so you deny your enemy territorial expansion, which is really what they're after in the first place. Thirdly, you deny the enemy a forward base of operations. If the enemy capture one of your cities, it means their troops only have to fall back a short distance to heal, which removes one of your advantages discussed above. Fourthly, you deny the enemy the added production power they would gain - this is vital, particularly in the Ancient and Middle ages, where units cost less.
Finally, if you have a bit of time before the enemy marches on your cities, rush-buy some workers. That way, abandoning cities isn't so much of a loss, and you can also have those workers rejoin the cities you're keeping. This will increase both their production power, and defense bonus if you can push them past size 6 and 12 with this.
Rule #3 - Gain allies!
Not just so they will attack your enemy, diverting their troops away from you, but also so the enemy won't form alliances against you! There is only so much outnumbering you can take...
Rule #4 - Show the enemy you can hurt them
The AI will come to the peace table eventually, but in order to broker a good deal you need to show the enemy that you can hurt them. Inevitably, this will mean a foray into enemy territory What type of unit to use depends on what era you are in. If it's the modern or industrial age the enemy territory will undoubtedly be covered in railroads and your force will be attacked before it even gets within striking distance of a city. In this case, fast units are essential. Even better are Marines, which can move from the sea to take a city in one turn, as opposed to tanks which will take at least two. In this case marines are more survivable than tanks, despite lower stats, because they spend less time out in the open. In it's the Ancient age, you don't really need to worry about being outmanouvered (the AI won't really use the tactics I've outlined) and you should go for swordsmen rather than horsemen. If it's the middle age, Knights or Cavalry every time.
I hope that helps some people out. I'm well aware that these tactics are by no means definitive, so feel free to chip in.
Finally, remember these (paraphrased) words of Winston Churchill:
"Let them have it. Avoid a fight if you can. But once battle is joined, by God let them have it"
from me or a huge amount of money or a vauable tech, I will never bow to them. 
