Pretty much the only way to survive against more than one computer player is to obsessively run the errands the computers ask you to do.  Of course, it hands out errands without regard to whether you can actually do them ... so my experience is that playing against more than one computer generally ends up with a point where all the AIs want me to do something I can't do (e.g., because my fleet is committed trying to hold off the non-allied AIs), and then they all declare war at once and kill me.

I think the single-player mode in this game is something of an afterthought and not really meant to be played.

The AI don't have to do missions to ally. They can just do it right off the bat. Kind of is annoying.

Ok, falls along the lines of what I said.  Force Locked Teams and you won't have to worry about an unfair advantage.

Lock the teams.

Your trying to play the game the hardest way possible.

I either play with locked teams and everyone is at everyone, or I team up all the vasari in 1 team and all the advent in another. Then its me against 2 teams, who also hate each other.

It also helps if you play on maps with few phase lanes, so that you only ahve at most 3 choke points to worry about. Then as TEC, you put as many repair bays as you can in the entry path of the block point, so that your fleets can be regenerated during the battle. Also include robot ships for the same effect. As Vasari, you use nano weapons, which will make the incoming ships helpless long enough to kill them. Advent ahve something else that gives defenders an advantage.

Your block points need jump inhibitors covering the width of the incoming phase lane, and a balanced fleet to counter anything that comes. Plenty of strike craft on carriers is a help.

You need to figure out what fleet will hold at each block point. Then use whats left as a strike fleet. That should be at least a 1/3 of your ship limit, which makes a good fleet.

The secret to block points is to use everything the game provides to help everything else. If you miss out something important, your defence folds. When its all in place in the right amounts, then it can hold easily.

I made the unfortunate mistake of not locking teams on my first 8 player map with AI on hard. I ended up with one or two key planets always being attacked. As a result, I had my entire fleet there with 7 repair platforms. Unfortunately, while I was holding off the enemy AI, I wasn't taking any worlds, I was distracted from my economy, and I wasn't doing missions. All of that combined to result in my allies going rogue. From there it was all downhill. I ended up wiping out an enormous amount of ships, and even a few of my allies fleets, at a modestly high cost.

At that point, I knew I was in trouble, but I figured if it could wipe out pink, who was right next to me and had only a planet and asteroid field, I could cut down my exposed flanks and start building up my economy. It would take awhile, but I'd win. Pink, however, was having nothing to do with this idea. Pretty soon, I've all but taken his asteroid field, and his fleet starts showing up from where-ever the heck it had been. Even though I was in 8th place for fleet size and had foolishly tried to play with no capital ships (not my best move), I was still winning against him, and even drove off an assault or two for the first few minutes thanks to my insane number of repair platforms. Then things got ugly. His friends showed up.

I was still trying to lock down that asteroid field when suddenly I was being steamrolled. Of course, things being as they were, it wasn't just pink's allies (and, by extension, MY old allies) come to call. It was everyone else and their grandmother too. So, at that point, with 3 different planets under attack by forces that completely outnumbered them even without the capital ships, a fleet already in tattered ruins, and ailing repair platforms, it was pretty evident that I was, well, screwed. And not in the good way. I surrendered, and checked the stats. It turns out that I had done rather well, even with as many mistakes as I'd made. I had at least a 2-1, possibly 3-1, kill to death ratio, and had killed about 10 capital ships, close to twice as many as anyone else had destroyed.

Being stubborn, I'm now trying to beat this match from a save point about an hour or so in, where my allies are still allies, my enemies are still enemies, and my fleet and economy still suck. That said, as I discovered yesterday (my second time through, after a few weeks hiatus), it's not impossible to complete missions, you just have to pick and choose when. I'm trying to keep them all above 80%, which isn't as hard as it sounds. The map is pretty open ended, even though I can't recall what it's name is, which gives me tons of places to defend but also tons of places to slip through, hit them in the rear, then run away.

The hard part is getting enough ships freed up to complete missions without losing them and weakening my defenses irrepairably. I ended up getting steamrolled by a huge enemy fleet that I didn't have a fleet big enough to defeat (3 enemy AIs sent practically their entire fleets. Go figure). The bad part is, even with major elements of 3 entire enemy fleets busy, my allies still didnt take the initiative to either defend my massively outnumbered defenses or launch a big counterattack elsewhere. We'll see what happens when I try again today...

I've never had an ally that is at 100% turn on me, yes I have had an ally who I failed to do missions for after getting to 100% and his allegiance declined so much that he did turn on me. I've never experienced that before, not saying that is doesn't happen, just that it hasn't happened to me.

This isn't true though The AI does need to have at least one enemy, obviously, but they don't randomly break alliances especially from 100%. In fact, I've won plenty of games where I stayed allied to an AI and we won a mutual victory.

I gotta admit, I'm a bit dismayed that many are suggesting taking the easy way out and locking the teams. For me, that's just never been fun. Since the game's release I've been playing huge FFA maps with 9 Hard/Unfair AIs, and the dynamics of diplomacy make it different each time.

It's a lot easier not have to worry about it, to be sure, but it's perfectly possible not to get ganged up on. Securing even a cease fire gets 2 AIs off your back - the one you have a cease fire with, and the other that is now getting attacked instead of you by the one you've got a cease fire with. And the others can't really cross the entire map and territories of a bunch of others just to get to you, usually.

I noticed AIs generate missions in most cases centering around neighbouring AIs (or players).

So if you have an AI in your neighbourhood and you shoot it (and you will), its most likely a gain in favour to somebody else in the vicinity.

Open up the diplomacy tab and see wich faction standing is raised by you (preemtive?) defense effords.

As soon as favour reaches 30% offer a chease fire treaty. Shooting a AI is decreasing favour, so you really don't want to shoot the factions with 30%+ standing unless you prefer being without allies or have a very good reason to do so.

Trade contracts should only be signesd if you CAN actually trade (ports) because this will reflect negatively upon you if you agree and can't really parcipiate and WILL be revoked and penalized.

Of course enemy AIs will still form treaties with each other but now you can participate accordingly.

You do not have to raid AI worlds or bribe AIs (even if it can help "picking" an ally at the cost of your expansion effords), simply defending your borders does the trick too.

The problem is not diplomacy mechanics, rather its poor documentation and the desaster new players are thrown into without a slight idea how to deal with the situation.

I find 2 vs 1 games with locked teams the most dyanmic.

I make the sole AI enemy difficult and tailor my AI ally to suit my tastes and handicap. So far, I get to play defensive and offensive games without being overwhelmed by pirates or the AI..as I have the ally to absorb the constant drip-drip-drip of trouble.