Ability Efficiency

Ability Efficiency linearly affects the energy cost of Warframe abilities. All Warframes have a base Ability Efficiency of 100%; Ability Efficiency over 100% indicates a reduction of ability cost while Ability Efficiency below 100% indicates an increase in ability cost. Ability Efficiency cannot go below 25%. The Arsenal will not display an Ability Efficiency above 175% because abilities cannot consume less than 25% of their base costs, but the Ability Efficiency stat itself is not capped.
==Mechanics==
When accounting for Ability Efficiency, ability energy costs can be calculated:
\text{Final Ability Cost}=\text{Ability Cost} * Max((200%-\text{Ability Efficiency}), 25%)
Channeled abilities drain energy at a specified rate. Ability Efficiency affects the energy drained at each tick as expected, but because Ability Duration affects the amount of time between these ticks, the formula for effective Ability Efficiency for channeled abilities is as follows:
\text{Final Energy Drain}=\text{Energy Drain} * Max((\frac{200%-\text{Ability Efficiency}}{\text{Ability Duration}}), 25%)
In the case of Ability Duration under 100%, Ability Efficiency above 175% is also taken into account, even though not depicted in the Upgrade-Menu. The final drain still cannot go below 25% of its base value. (See the graph on the right for examples.)
The in-game energy bar display is rounded down to the nearest whole number, but the costs of the abilities are not. This results in the discrepancies in the apparent cost of abilities with Ability Efficiency mods. For example, an ability with 25 energy base cost will cost 17.5 energy with maxed (+30%). If this ability is used multiple times in a row, it will appear to cost 18 energy, then 17 energy, then 18 energy, then 17 energy and so on.
===Energy Drain for Toggled Abilities===
Some abilities are toggled on and last until the user turns them off or runs out of energy, such as 's or 's . Energy drain for these toggled abilities depends on both Ability Efficiency as well as Ability Duration. See the related section for a full explanation.
===Other Behavior===
Some Warframe abilities do not cost energy to cast, thus ability efficiency has a unique effect on these abilities:
==Modifiers==
, , , the Arcane Enhancement , and the positive Ability Efficiency Arcane Helmets stack additively. Stacking with Trinity Meridian Helmet or Ash Scorpion Helmet does not appear to follow this formula; this suggests stacking is different when you have a helmet that reduces Ability Efficiency.
===Mods===
, , , and reduce ability costs linearly based on the percentage shown on the mod card. , instead, increases ability costs.
StreamlineMod.png|link=Streamline|
FleetingExpertiseMod.png|link=Fleeting Expertise|
Boreal'sHatredMod.png|link=Boreal's Hatred|
BlindRageMod.png|link=Blind Rage|
SystemRerouteMod.png|link=System Reroute|
NecramechStreamlineMod.png|
HeightenedReflexesMod.png|
NetraInvocationMod.png|
SeismicBondMod.png|
TheRelentlessLostMod.png|
===Arcanes===
 is currently the only Arcane Enhancement that affects Ability Efficiency.
PaxBolt.png|link=Pax Bolt|Pax Bolt ( upon Headshot Kill)
===Arcane Helmets===
Arcane Helmets also reduce (or increase) ability costs linearly based on the percentage shown on the helmet. This was removed following the 13.2.3 Patch. The following helmets used to affect Ability Efficiency:
LokiEssenceHelmet.png|link=Loki Essence Helmet#Arcane Variant|Essence Loki Helmet 
NyxVespaHelmet.png|link=Nyx Vespa Helmet#Arcane Variant|Vespa Nyx Helmet 
BansheeChorusHelmet.png|link=Banshee Chorus Helmet#Arcane Variant|Chorus Banshee Helmet 
AshScorpionHelmet.png|link=Ash Scorpion Helmet#Arcane Variant|Scorpion Ash Helmet 
TrinityMeridianHelmet.png|link=Trinity Meridian Helmet#Arcane Variant|Meridian Trinity Helmet 
==See also==
* Maximization
* Ability Efficiency Research
es:Eficiencia de habilidad
Category:Mechanics