Gate Camp
Gate camping is the act of focused area denial; specifically, using ships on one or both sides of a stargate to either prey on unsuspecting pilots jumping through the gate or to ransom the pilot. High-security gate camps are often difficult to achieve unless the two sides are at war, as warp disruptor bubbles cannot be onlined there and the camp must rely on tacklers. Pirates and 0.0 alliances are the two main users of gate camping as a tactic.
Tactics
Escaping
One of the best ways to avoid being caught in a gate camp after jumping into one is to have a fast ship equipped with an afterburner or micro warp drive. These allow your ship to move more quickly and especially in frigates will permit you to escape any warp disruption bubbles; however this does not prevent you being warp scrambled or jammed with a conventional device. Ships equipped with a covert ops cloaking device are difficult to catch if the device is activated quickly enough after losing the initial jump cloak, and ships combining these two elements are nearly impossible to catch with a skilled pilot at the helm.
Equipping warp core stabilizers will help neutralize the effect of a warp disruptor, but it will not counter an interdiction sphere or warp disruption bubble.
If there is no bubble or tackle at the gate, warping off is probably the most effective counter. However, this is a rare situation. For most ships the most effective tactic is to avoid aggressing any pilots, wait for the cloak on your ship to drop in time (thus confirming the end of your session change timer), move back to the gate and jump back through.
Avoiding
Fleets and high-value ships will typically use scouts in covert ops or interceptors to jump through ahead of them to confirm the safety of the route.
Map statistics modes to show pilots in space or pilots destroyed in space can be good indicators of gate camps. High values for these statistics on a system with no real significance is a good indication that a gang may be waiting in that system.
Execution
Gate camps are typically performed by fleets or gangs. Sniper ships and damage dealers will sit at optimal range off the gate, while tacklers will usually be on the gate orbiting at 12km. By orbiting at this distance there is a chance that they will fly close enough to a cloaked ship that has just jumped through to actually decloak that ship. In larger camps this makes it difficult for new targets to stay hidden.
ECM is often used on gate camps to neutralise damage output of hostile ships; in particular electronic attack ships are ideal for this role, as they have a fast locking time.
The lock time on ships is crucial in gate camps, as the target must be engaged as soon as possible after they jump in; if they are not locked rapidly then they will not be destroyed rapidly enough to prevent them either warping off or reapproaching the gate.
Ship Types Required
Every gate camp needs a certain mix of ships to be successful. It is possible to camp a gate solo, however that ship would then have to fit modules for all of the roles that are described here.
Tackler
Tackling ships are probably the most important ship type to have at a gate camp, without them there is no point in camping as you will not be able to stop the target from warping off. The best types of ships for this role are those with high speed, and fast lock such as interceptors or their Tech 1 equivalent. The Keres is underutilized currently in this role but has bonuses to warp disrupt range that would make it ideal for this role.
Tackle Assist
This role is used most often at low sec gate camps where a larger ship such as a heavy interdictor is given a remote boost to scan resolution to provide a faster lock. in a null sec environment this role can be a light or heavy interdictor that can deploy an area effect warp disrupt to prevent escape. Specialty ships such as rapiers and other ships equiped with webs or energy neutralizers can further slow down the target to prevent escape.
Damage Dealers
Although this seems obvious, there have been many occasions where not enough damage can be done to actually destroy the target before it can escape or help arrives. Cruisers, Battle Cruisers and Battleships fit in this role, as can any ship that has a high damage output.
Ships equiped to prevent the target(s) from shooting back are especially important in the case where there are multiple targets to be destroyed. These ships will keep the tacklers alive and allow them to 'hold' the queue of targets in place while they are systematically destroyed. They can also prevent the targets from remotely assisting each other.
Scout
A scout or multiple scouts are important to deploy on the other side of the gate as well as other adjoining systems to warn of larger or better equipped fleets that may be on their way to 'break up' the gate camp.