The Destroyer (also called a "dessy") used to be one of the most overlooked and neglected ships in Eve. Thanks to recent changes to the existing Destroyer hulls in Inferno, plus the introduction of four new Destroyer hulls in Retribution, Destroyers are now very versatile and effective!
There are few things in Eve funnier than a Battleship that encounters a fleet of 15 Destroyers and smack talks them, laughing in local at their small ships. The pilot doing this is making a critical mistake and failing to use the basic skill of mathematics. First of all if you have 15 ships against you, each bearing 6 to 8 weapons, then that is 105 to 120 weapons directed against you. Lets say each gun can manage 20hp at a volley and has a fire rate of 3 seconds (which is VERY conservative for a destroyer with good skills) then we have a damage per second ratio of 800. With 30hp hits and 2.5 sec rate of fire (a decent approximation for reasonable skills) we are looking at 1440 damage per second. 1440 dps all aimed at a solitary battleship, means that battleship isn't going to last long at all.
A Destroyer is essentially three frigates in one platform. They have the guns of two frigates but their tracking bonuses give them almost another frigate worth of striking power. That fleet of 15 destroyers is, in essence, a fleet of 40 to 50 frigates. The only drawback being that a single ship loss takes out 2 to 3 frigates rather than just one.
Because each Destroyer represents a significant amount of DPS, ship losses are more significant to a Destroyer fleet than a Frigate fleet. As Destroyers are somewhat slower and less agile than Frigates. Where a frigate fleet can warp out of cloak extremely fast, a destroyer accelerates more slowly. Evasive maneuvering and spaceship command skills are particularly useful to flying Destroyers.
Because of this, controlling the range of a fight is very important to Destroyer survival. In PVP-BASIC, it was important that your situational awareness focus on where your ship was in relationship to the target. In Wolfpacks, the situational awareness shifts its focus to not only where your ship is in relationship to the target, but also where your fleet is in relationship to the target. In PVP-BASIC, we showed you how to "bounce" your ship in and out of the fight - in PVP-WOLFPACKS, you will be exposed to us "bouncing" the fleet in and out of the fight (technically, we call this a "fly-by," by the way).
Strengths and Weaknesses
The key to effectively flying Destroyers is the same as the key to flying any other ship: understand its weaknesses and its strengths, and fly it with them in mind.
First of all lets consider the weaknesses and get them out of the way:
Somewhat low shield and armor hp. Destroyers used to have barely-minimal tanks, but thanks to recent changes to the hulls, they now have shield and armor hitpoints that are appropriate to their size, especially in relationship to Frigates and Cruisers. While they still can be considered "glass cannons," a Destroyer fit with a DCU can survive 2 or 3 bombs relatively easily. With a small armor or shield tank, the Destroyer now can hold its own in a variety of circumstances.
Larger and slower than a Frigate. Without assistance from modules, the destroyer is slower than a frigate and less agile, and is easier to hit than a Frigate. It is, however, more agile than most Cruisers.
On the other hand, Destroyers have many strengths:
Lots of high slots and turrets. All of the original Destroyers pack the maximum 8 high slots, and the new Destroyers released in Retribution all have at least 6 high slots. The huge number of guns can give Destroyers a massive volley damage (aka alpha strike).
Phenomenal Role Bonus. All Destroyers have a 50% role bonus to their weapon type range and/or velocity, depending upon the hull's base weapon. This allows the Destroyer to hit at much greater ranges than Frigates, while using the same size turrets/launchers as Frigates.
Hull Bonuses. Each Destroyer has a weapons-related bonus, generally 10% per level trained of the Destroyer skill, further enhancing the effectiveness of its turrets/launchers.
One of the obvious things that emerges out of this is that Destroyers are not necessarily intended to sit in a blow for blow slug fest with another ship, except vs frigates or possibly other destroyers. Many T1 Frigates or covert ops ships would get chewed to metal by a Destroyer. However, most tank-heavy assault ships would kill the destroyer without too much effort. You can kill an interceptor one on one with a Destroyer (though you are likely to only force a stalemate as the interceptor can get away), and assuming you can mitigate its incoming damage, you can also kill a number of common T1 Cruiser fits.
What should be clear by this point is that the Destroyer works most effectively when it is ganged with others, either in a small gang or a large massed fleet.
There are numerous different ways to fit a Destroyer depending on what you want to do with it. However, there are some constants with fitting a Destroyer and flying one. First of all make sure you bring enough ammo to reload your guns once or twice - Destroyers chew through ammo unbelievably fast.
As with Frigates, Destroyers can be fit for short, mid or long range fighting, and also as with Frigates, you REALLY WANT TO FIT A DAMAGE CONTROL UNIT.
Destroyers tend to be a bit tight on the powergrid, especially when fitting T2 turrets/launcher, which can limit some of your tanking options. Training Electronics and Engineering to level V will ease your fitting headaches immensely. For the most fitting flexibility, get Weapons Upgrades V and Advanced Weapons Upgrades to any level as soon as possible.
If you are gate camping, it is usually best to fit your guns for an optimal of at least 16km. This way, if you are sitting on a gate at zero, you will be able to hit most targets coming through the gate (unless it is a huge regional gate).
Destroyers can easily be fit with a small shield or armor tank, although this tends to be more common for solo and very small gang fights and less common in larger Destroyer gangs and fleets.
When fitting for a wolfpack, remember that your hydra has fewer heads and the heads are a bit slower. With that in mind you can apply science to fit the fleet and make it work. Also, remember that this is a destroyer, not a small cruiser. It doesnt fly or fight like a cruiser. It is a frigate with a hell of a lot of teeth.
See also: Destroyer Tactics