Every ship in Star Trek Online has the same four power sliders: weapons, shields, engines, and auxiliary. Most players set them once from a build guide and never think about them again. That works, but understanding what each point actually does lets you change the preset for a specific fight, and it explains why different builds want very different settings. This guide covers the arithmetic, using the rules as they stand in Season 37 (September 2026).
All ships share a base pool of 200 subsystem power split across the four systems. Raising one lowers another. You can set any system anywhere between 15 and 100 by hand, and most systems have a default cap of 125, which items, traits, and abilities can raise. Power above the cap does not add damage directly, but it is not wasted, as the weapons section below explains.
Console players get four presets on the D-pad: 100 weapons with 50 shields, 25 engines, and 25 auxiliary, and the three variants that put the 100 in shields, engines, or auxiliary instead. On PC you can set any split you like and lock a slider so it does not move when you adjust another.
Weapon power only affects your energy weapons. It has no effect on torpedo launchers or mines. The multiplier on energy weapon damage is:
Multiplier = (Weapon Power + 100) / 200
That means every point of weapon power is worth half a percent of damage, 100 power gives exactly 100%, and each point above or below moves it by 0.5%.
| Weapon power | Damage multiplier |
|---|---|
| 50 | 75% |
| 75 | 87.5% |
| 100 | 100% |
| 110 | 105% |
| 125 (default cap) | 112.5% |
Firing an energy weapon also temporarily deducts its power cost from your current weapon power for the length of its firing cycle, and refunds it at the end. The interesting part is overcapping. Any weapon power above your cap acts as a backup pool that refills what your weapons are using, at your power transfer rate. The wiki's own example: with 150 power and a cap of 125, you fire eight beams costing 80. Your power drops from 125 to 45, then climbs back toward 70 during the cycle as the 25 points of overcap refill it, and jumps to 125 when the cycle ends. Without the overcap it would stay at 45 the whole time.
The shield subsystem does not change how big your shields are. It changes how fast they regenerate and how much damage they absorb. Each point of shield power gives 2% of the regeneration rate shown on your shield array, so 50 power is 100% of it. Each point also makes your shields negate 0.2% of the damage they take, so 50 power is 10% hardness. Both scale linearly, which makes it easy to see what a slider change buys.
Engine power sets your speed. With 50 power you move at base speed, each point above adds 2%, and each point below removes 2%. Speed also raises your defense rating, which is one reason pilot ships run engines high. Two related mechanics are worth knowing. Flying in reverse for more than 10 seconds builds a Reverse Power Drain that removes 1 power per second from every subsystem, up to 25 points each. And Full Impulse routes almost everything to engines and drops weapons, shields, and auxiliary to 5, so entering combat at Full Impulse leaves you with badly weakened weapons until power is rerouted.
Auxiliary does more than it looks like. Each point gives 1 stealth and a 1% recharge reduction for hangar pets. Each point above 50 raises the potency of science abilities by 2%, and each point below 50 lowers it by 0.6%. Engineering abilities that use auxiliary, such as Auxiliary Power to the Structural Integrity Field, scale with it as well. That is why exotic builds try to push auxiliary well past 100, and why a common energy build sits at 70 rather than dumping everything into weapons.
You rarely play at bare slider values. Skills, warp cores, engines, deflectors, and traits add power on top of your slider, and some add to the cap. Performance skills give a flat amount to a subsystem. Efficiency skills give a larger bonus the lower a subsystem is set, which is why running a system low costs less than the raw slider numbers suggest. The Electro-Plasma System, or EPS, controls how fast power moves between subsystems, and an EPS Flow Regulator console or the Engineering captain's EPS Power Transfer ability speeds that up. Auxiliary Power to the Emergency Battery is a good example of using this: at rank III it adds 19 power to weapons, shields, and engines for 10 seconds while removing 45 from auxiliary.
Start from your build type. Energy builds want weapons at 100 with auxiliary as the second priority. Exotic builds want auxiliary as high as they can get it. Pilot ships, like the Fleet Nova build described in the exotic guide, lean on engines. Tanks published by the STO BETTER community run high weapons and high auxiliary with moderate shields. Then test the change: record a run with the /CombatLog command, change one slider group, record again, and compare in the Combat Log Reader. For the bridge officer abilities that move power around mid-fight, see Cooldown Reduction Mechanics, and for how weapon power fits an energy build, read The Anatomy of a Meta Energy Build.