AI War:Engines and Speed (including Tractor Beams and Gravity Effects)
|This page is up to date for game version 5.033 and should still be correct.|
A ship's base speed is found in white text on the third line of the description box as, for example, "Speed: 48".
While ships do not accelerate or decelerate instantaneously, the rates of acceleration and deceleration are so great that ships spend most of their time either stationary or moving at their current top speed. Acceleration is normally only noticed for very fast ships like Scouts and Transports.
If a ship's current top speed is different from its base speed then the current top speed will be displayed in yellow text in the first line of a ship's description box next to its name.
Ships' speed can be reduced in three ways:
Ships with the Ability: Engine Damage damage a target's engines with each shot.
The amount of engine damage done is a flat number that is subtracted from the target ship's Engine Health, which is also a flat number.
When a ship takes engine damage, its speed is modified in a linear progression.
So if a ship takes 25% engine damage, its base speed is now 75% of what it was.
At 50% engine damage, its base speed is cut in half.
Mobile ships always have a base speed of at least 1, even if their engine health is reduced to 0.
Ships with 'Engine Health: Inf' just ignore engine damage. Other effects of the shot, such as health damage, are not ignored.
Stationary structures are given 'Engine Health: Inf' even though they are stationary so the game does not waste processing power trying to compute engine damage for structures that cannot move.
Tractor beams, such as those emitted by the Tractor Beam Turret, grab a ship and hold it in place until the tractor beam emitter is destroyed.
A ship's speed is effectively 0 for as long as the tractor beam lasts.
Mobile tractor beam emitters, such at the Etherjet, hold ships in a fixed position relative to themselves as they move.
A tractoring ship is always considered in-range of any ship it is tractoring, although it might be untargetable for some other reason such as cloaking.
Unlike attacks, tractor beam emitters do not suffer penalties for being protected by a force field; in fact it is recommended that you place a forcefield over crucial tractor beam emitters so they stay alive longer.
Gravitational fields, such as those emitted by Gravitational Turrets, impose a fixed limit on the speed of enemy ships within the field.
Gravitational effects are applied after speed boosts, so even a ship that should have a speed of 500 will have its speed reduced to 8 when caught in the gravitational field of a Gravitational Turret Mk I.
Gravity Drills are a special planet-wide equivalent, although they affect both friendly and hostile ships. The Grav Driller AI will use these to reduce all ship-speeds to 8 on affected systems, which can result in extremely slow gameplay, including exo-waves.
Ships not being slowed
The Immunity: Speed Boosts, Tractor Beams, and Gravity Effects all do exactly what they say and render a ship immune to those effects.
A ship with 'Engine Health: Inf' is effectively immune to engine damage.
One surprise that can allow multiple ships to bypass your tractor beams or gravity effects is the Fleet Mechanic.
Because these fleets often warp in several systems away from the human territory, the escorting fleet does not move as normal, rather they hold position on the major ship leading their fleet.
When an escort ship is holding position on their fleet leader, its speed is boosted or reduced as necessary to stay next to its fleet leader and the fleet leader shares its immunities with its escort fleet.
So a Missile Frigate that normally has a speed of 44 when part of an escort fleet for a Hybrid Hive would have its speed boosted to 100 to match the Hybrid Hive and would gain the Immunity: Tractor Beam that the Hybrid Hive has.