The special equipment Automated Repair "heals" a each ship that is equipped with it up to 15% of its maximum "hit points" per turn. The special equipment "Advanced Damage Control" does the same thing for 30% of its maximum hit points. If the user of these specials can reduce the damage their ships take per turn below those thresholds, they can essentially make their ships invincible. This can be achieved with high levels of maneuverability and shielding and can make Assault class ships with their massive hit point totals very hard to destroy. These technologies are researched under the Construction field.
The Repulsor Beam technology, a low level tech from the Force Fields research tree, pushes enemy ships away from the equipped ship, keeping them at a minimum distance of 2 at all times. This makes range 1 weapons completely useless against the equipped ship.
There are 3 ship special equipment items that have a chance to shoot down missiles that would otherwise hit the ship. The Anti-Missile Rockets technology is researched through the Weapons field and has a 40% chance to destroy each missile minus the "tech level" of the missile. The Zyro shield technology, from the Force Fields research field, has a 75% chance to destroy each missile minus 1% per tech level of the missile. The Lightning Shield technology has a 100% chance to destroy each missile minus 1% per tech level of the missile.
The Stasis Field technology essentially takes a target out of play for a full turn when it is fired, essentially "turning off" one target per turn. This can be very powerful if certain enemy ships are vastly more powerful than others.
The Black Hole Generator, a very high level Force Field research technology, flat out destroys huge numbers of ships and missile bases. Each time it is fired, 100% of the enemy ships or bases are destroyed minus 2% for each shielding level they have. With Class XV Shields (the highest) installed, 70% of all ships of a given type will still be instantly destroyed every time the Black Hole Generator is fired. With Class XX Planetary Shields and Class XV Shields installed, 30% of all bases will still be destroyed every time this weapon is fired.
Two special weapons, the Energy Pulsar and the Ionic Pulsar, do damage to all ships in a stack at the same time. These are researched in the Propulsion research field. The Energy Pulsar does 5 damage + 1 per 2 equipped ships to each ship in the enemy stack and the Ionic Pulsar does 10 + 1 per equipped ship to each ship in the enemy stack. These can be extremely effective against tiny ships which have very low armor and moderately effective against medium ships. With only half a dozen or a dozen equipped ships they can potentially defeat 32,000 tiny ships in one shot (the max of any 1 type that can be built).
The Sub-Space Teleporter technology allows an equipped ship to always move first in combat and to instantly teleport to any square on the battle grid for its movement. The Sub-Space Interdictor technology, when researched, is automatically equipped by all of the planets the researcher controls and it blocks this technology from working completely when the combat happens over an equipped planet. The equipped ships effectively operate as if the space is completely wasted while they are subjected to it.
The Ion Stream Projector and Neutron Stream Projector are researched through the Weapons field and work in a way similar to the Pulsar weapons. The Ion Stream Projector deals 20% of the targeted ship's current hit points in damage + 1% per firing ship, up to a maximum of 50%. The Neutron Stream Projector deals 40% plus 1% per firing ship, with a maximum of 75%. The minimum damage of these weapons is 1. These weapons have a range of 2 spaces. These can "wear down" entire stacks of enemy ships very quickly, leaving them to be destroyed in droves by your other weapons, but these weapons are very bad at killing enemy ships completely on their own. Whereas the pulsars are very good against small ships and worthless against large ones, these are much better against large ships and mostly worthless against small ships.
Most weapons can only destroy 1 ship per 1 weapon and any excess damage past what is required to kill a ship is wasted completely. A weapon with 100 damage would only kill 1 ship regardless if its max hit points were 1 or 100. Two weapons ignore this rule. The Graviton Beam deals 1 - 15 damage and the Tachyon Beam deals 1 - 25 damage, both weapons damage carries over from one ship to another if there is any left over damage. These weapons can be very good at killing tiny ships in large quantities.
Multiple shot weapons act similarly. These fire either 3 or 4 shots per weapon per turn, usually for lowish damage, and can kill huge numbers of smaller ships very quickly. Excess damage per hit will be wasted, but they make up for that with number of shots fired per turn. Three or four shots per weapon is potentially 3 or 4 kills per weapon, especially against tiny ships.
Scatter Pack Missiles (V, VII, and X) each split into that many separate missiles after launch before they hit the target. A missile base or ship equipped with these can potentially launch tremendous numbers of missiles per turn against small ships. These missiles tend to be low damage so heavy shields make them entirely useless, but against tiny and medium ships which often don't have the space for excellent armor they can do potentially much more damage than single missiles of the same approximate tech level.
The Stellar Converter, a normal weapon researched through the Weapons field, says "hits all 4 shields". Ignore this text. This functionality was removed before the game went live. This weapon functions similar to other multiple shots per turn weapons by doing 4 separate attacks.