Personally, before researching weapons, I look around and find the guy I'm most likely to get into a war with first and build a weapon and defense he's weak against. After that, I add a secondary weapon or defense if he adapts. As far as fleet composition goes, I know that some people have some min-max combos of roles but personally, I like to have a balance in my fleet to avoid cheese. Hull size is a personal preference but when you get enough manufacturing points, you'll be building large hulls in no time.

Welcome to Galciv 3 btw!

Are you sure about the dual defenses? I could have sworn they DID build them. Can anyone else confirm what he's saying because if that's true how in the blue hell isn't this addressed in a patch yet?

The AI use "Best Defense" for equiping defenses, now that usualy means 1 type as 90% of the time they are ahead in one branch of the tech tree. BUT, it can so happen that they are equal in tech and on the odd, and its very very rare you may see an AI ship with more than one defense and even if you do you will notice that it is not equaled out very well, you would see 200 shields and 16 armor for example.

Hmmm, another technique for stronger ships is to only build ships with strategic resources (Elerium, antimatter, etc) for their weapons. A ship with 2 antimatter missles for 32 missile attack can be very potent early in the game. A fleet of such ships can be deadly. You need only research the basic weapon techs in order to have access to these.

If you choose this path, you will need to mine, and mine and mine some more. Plus, you will need to research any advanced mining techniques in order to increase the number of resources (more resources = more fleets).  If you research at least the basic defenses, you can design ships to resist the enemy's preferred attacks- with sufficient fleet strength, you can build fleets that will survive battles with minimal loses.

Late in the game, your ships will start to lag in potency, so you need to finish the game early, before turn 200 at least.

People talk about "tall" versus "wide" empires- where you decide to have fewer awesome planets versus many average ones. Using strategic resource equipped ships is the "tall" strategy for your fleets.  As you will have fewer, more powerful fleets, you will need to research enough movement tech so that they can cover more ground to counter the numerous, but less powerful enemies.

Worth a try.

Starting out I try to research hulls up to medium and provide them with a single weapon system I research beyond the base level. (one or two additional levels if possible). Which ever one I choose -- and it changes game to game -- is my primary weapon type and make up the Big guns of the fleet. I research advances in the other two as opportunity permits and use them as secondaries. I rarely have all three types on the same ship until I get huge. A Battleship needs a lot of variety.

In fleet construction I go for combined arms, weighted heavily toward my primary weapon type. Medium destroyer classes or the large Cruiser class all mount a main system and a secondary. Small ships have specialized missions and usually have a single system. By using a little of everything, I have the all range categories covered, wear down all their defenses, and usually have something they haven't covered with defenses. While I do select my secondary system load outs based on the weapons and defenses my opponent chooses, the primary system is not; that one usually gets picked before I meet anything armed except pirates. Instead of designing ships to go against a specific enemy, I organize fleets using ships that give advantageous match-ups.

All defenses are researched evenly as much as possible until I find out one isn't needed. Then I don't research that one until I get ahead in other techs. Right now I'm in a very peaceful galaxy where the second and third rated civs are using the same weapons. This is mostly Energy, but both have the occasional slug thrower on large ships. (I'm the only one with huge right now.) All my ships (except tiny) have shields and at least token levels of armor -- as do both opponents. My main weapon this game was missels, and neither of them have much in defense against them.

There's a wiki page on ship roles.  You can't just use assault, that will get you murdered.  To really have a powerful fleet, you need to utilize those roles to hide high power, low defense ships behind high defense ones, optimizing your damage output without reducing your durability.

I'm not argueing support roles i just don't put enough thought into it. If you don't have medium ships yet. You wouldn't want a fleet full of suport ships. Assault is better than that. Once you have medium or better ships like i said I'm sure someone else would be better for advice. What my point is a lot of colonies and good infastructure is as good if not better advice for combat. Someone needs to talk about infastructure.

Ok thanks everyone for the info.  It also sounds like everyone is making custom ships, I was using the default ones until I understood the game better, but I'll start using it.  I'll try the tutorial again this time I'll also skip the support ships, and use the mining materials for prototype ships instead of saving them for planetary improvements.