General Design Doctrines

In the game, there are a few prevailing design doctrines that most ships can be classified into. Below are the basic doctrines from which most others are derived:

 Rapid-fire doctrine 

Best against: Fast doctrine

Bad against: Tank-Sniper Doctrine

This design doctrine favors sheer DPS above all, often sacrificing armor and speed in the process. They are typically seen with a large amount of guns as well as auto-loaders. The massive barrages these ships unleash are good against faster, less armored opponents. However, these ships are more susceptible to critical hits like flash fires and ammo detonations. This design doctrine is most commonly seen in fleet cruisers and battlecruisers, but can be applied to any ship size.

 Tank-Sniper doctrine 

Best against: Rapid-fire doctrine

Bad against: Fast doctrine

Tank-Sniper ships often sport average speed, very large guns, and nigh impenetrable protection with top notch fire control backing it up. Most commonly seen on large battleships or raider cruisers, ships of this doctrine are quite costly to produce but will trump nearly anything in their path by scoring critical hits at long range. Their only weakness is a larger Tank-Sniper or a large swarm of fast ships that take advantage of the Tank-sniper's long reload time to deliver lethal volleys of torpedoes.

 Fast doctrine 

Best against: Tank-Sniper doctrine

Bad against: Rapid-fire doctrine

Ships of the Fast doctrine tend to be cheaper in nature and use swarm tactics against large targets like Tank-Snipers. They use their numbers and very high speed to close in and deal devastating damage with torpedoes. Most ships of the smaller variety tend to lean heavily on this doctrine. However, a ship following the Rapid-fire doctrine will mow your swarm down due to its rate of fire. Attempts to implement this doctrine on a large hull have led to the creation of a class of ships termed "Memeships".

Now for some nation-based doctrines for large ships:

 USA: 

Most of your ships should follow the Tank-Sniper doctrine to compensate for their below-average resistance.

 Germany: 

Your ships should follow a Tank-Sniper doctrine, but you can also build Rapid-fire ships due to their increased resistance.

 Britain: 

Use a Rapid-fire or Fast doctrine due to your lack of super-battleships. No, the Super Battlecruiser does not count.

 Russia: 

Definitely use a Rapid-fire doctrine due to high resistance.

 Japan: 

Use any doctrine, they have a hull for all of them.

 France: 

Use a hybrid of Fast and Tank-Sniper doctrines, as you are often limited to 3 turrets.

 Generic countries: (Spain, Italy, Austria, China) 

These countries tend to be lacking in super battleships, so go with a hybrid of Fast and Rapid-fire doctrines.