I have gone for the defense approach. I find that the ai usually picks one type of weapon attack, beam or mass so I get the armor and stack the heck out of it. The sub zero armor for example is only 4 or 5 space and gives 10 d. They cannot hit my huge ships which each have over 100 defence and then the 30 offense will make them quite deadly. My huge destroyers in my last game had 140 defence each. I would use 1 to take out huge stacks of the enemy. Big defence ships is my style but I know most people like the powerful little to mid size ones. The main advantage is after I fight all my ships are still there. When I used the smaller ones I would lose some ships and have to replace them.

I routinly play challenging and above in large galaxies. What I do is put on at least 4 engines, usually 4 on most of my ships, unless its a fighter. then i load the rest with weapons until its max, and if at all posible, i put on armor/life support, depending on how spread out i am and need range. Thus, this allows me to be NASTY with the enemy, using guerilla tactics almost all the time, ie, hit and run, hit and run, hit and run, until he has no more ships, then go on a rampage destroying the ships on planets and attacking as i progress. i find this works VERY effectivly, and it does not matter wether your using high, low, or so-so techs, the enemy loses almost every single battle.

Armor is NOT needed in most cases, as if your being attacked, the AI is stupid enough to send fighters vs 3-4 battleships, or 3-4 battleships vs 20 highly advanced fighters. (In the few cases where I'm attacked, anyways, as most of the time, I run from a planetary fleet, using my extreme engines to hit the enemy, and run away again before it even gets the idea to attack the fleet.)

I also refuse to fight without a fleet. IMO, most of you people that are using armor are wasting time. Try using weapons as armor sometime, you'll find you win a lot of battles. As long as you keep in mind to keep the speed at an extreme, keep the firepower at an extreme, and attack first.

ps: for defending planets, I usually alter from that tactic slightly, puting on a little armor so the ships can survive being attacked so that the higher damage ships can rush in from a nearby standby position and terminate the enemy.

With the current AI being so dumb, guerilla tactics work. To a massive extent. Even if I'm overwhelmed, for every ship I lose, the enemy loses at LEAST 5, even if same tech. If I have a tech advantage, for every ship I lose, they lose 20. Dare all you people who scream armor is necessary to play a game without armor, at all. You'd be amazed

Going without armor is, imo, a waste of an excellent line of tech. Even the tiniest bit of armor, I've found, can go a looooong way. There's no need to get 100 armor or whatever on a ship- just 2 or 3 grants you a huge advantage without much cost in space.

The best ship I ever built (and only ever built one of it) was called the Behemoth

Huge hull
2 hyperwarp mark 3
2 sensors mark 4
2 advanced life support
1 Black Hole Eruptor
a LOT of ultimate invulnerability

Not just any old ship, this thing was my last ship on the map after an extremely bloody war. It removed the entire Torian army from this plane of existence. Cost a lot, but it couldn't be killed at level 0. By level 28 (pre the 1.1 level nerf bonus, which was a good idea in retrospect) it could stand any ship I've ever seen/made in a one on one battle

I don't use life support except at the beginning for some colony ships. But I play on medium maps, which strangely doesn't seem popular??

I also don't research defensive techs. Superior speed, sensor and overwhelming first strike is my basic strategy.

I also value logistic techs a lot, so I can bunch up enough ships for sufficient attack in the first shot.

On huge and gigantic maps, defence is vital.

And as for cargo ships: no way do I want to waste that much money on kamikazi frigates, if in the same time for cheaper I can get out ships that do less damage but survive the counter attack

I don't normally use life support, even on gigantic maps. I was going to post about that, but then decided it was my play style. I prefer a forward base of operations for a war, so I generally send a task force ahead of the main fleet to establish a star base or take a small fringe colony so that my range is extended. That also gives me somewhere close by to hide while I repair any ships that might need it, and a good rally point position for incomming reinforcements.

I agree with the idea of 2 engines. Works great for me. I occantionally will build a few with 4 or 5 engines and a pea shooter to take out transports quickly should the need arise.

I'm pretty new at this, but when you research a new tech (ion drive f.i) do you design a new ship and obsolete the old one or do you build the outdated hyperdrive and upgrade the ship when it's done?

I don't know what to do and if I upgrade the design all the time I will end up with a hundred ships! And that's just for the humans!!

At almost every new research level I redesign my ships with the new tech. I then obsolete the older design but leave the existing fleet alone (maybe to get upgraded later). After a few games of doing this with a civ, you have all the ship designs you can use and you can keep the buildable list small by continuing to obsolete anything that you will no longer build.