All this data is potentially out of date, and should be taken with a truckload of salt
Dreadnoughts are among the largest ships in the EVE universe. So large in fact that they cannot fit through the normal stargates used by smaller ships. Instead they rely on their own on-board jump drive to rip open the fabric of space and instantly traverse the huge distances between star systems. Doing so requires two things:
- The dreadnought needs racial specific fuel - derived from ice mining - present in it's fuel bay.
- The dreadnought pilot requires a fleet member to activate a cynosural field in the target system to give his jump engine something to lock onto in order to jump.
A dreadnought is fitted with the same regular modules as all other ships. Weapons, shield boosters or armor repairers. Albeit of the extra large variety. Dreadnoughts can also only fit between 3-4 weapons making them slightly less powerful than a battleship. This is under normal circumstances. What makes the dreadnought unique is it's ability to fit and use a siege module.
When activated this module will render the dreadnought completely immovable for 10 minutes. Additionally, it cannot receive remote assistance in any way. At the same time the dreadnought receives a massive bonus to it's firepower and the effectiveness of it's tanking modules making it a stationary engine of complete destruction.
Dreadnoughts, especially "in siege" is not very effective against smaller targets due to severe tracking limitations. The primary role of the dreadnought, therefore, is to put extreme amounts of damage onto static targets with millions of hitpoints such as outposts and POS. Often a fleet of dreadnoughts can reinforce or kill a POS in a single siege cycle (10 minutes) that it would take hours for a fleet of battleships to kill.
Hot drops and capital fleet fights
One way of defending your POS and outposts in deep 0.0 is the "hot drop" strategy.
The defending party will set up a fleet of dreadnoughts a few jumps from the assaulted system. When the enemy dreadnoughts go "into siege" a small fast ship will warp in close to them and open the cynosural field at which point the defenders will jump their own dreadnoughts into the fray. The attackers who are immobile for 10 minutes have no choice but to fight.
As there is no way to remote repair or otherwise aid a dreadnought in siege, these "hot drops" can sometimes turn into a total slaughter. In a few moments tens of billions of isk-worth of dreadnoughts can be annihilated. The "hot drop" or capital fleet fight is undoubtedly the end game of PVP in EVE.