Shield


 * For the health class, see Damage 2.0/Shield.

Shields are invisible barriers that absorb incoming damage and protects the player from taking Health damage against enemy attacks. Unlike health, shields regenerate after three seconds of not taking damage, making them a naturally replenishing defense. All Warframes except Nidus and Inaros possess shields, whose values can be seen in the upper right of the player's UI as a blue number, with each Warframe possessing different amounts of maximum shields. Corpus units also make extensive use of shielding, along with certain bosses. When a player's shields are depleted, the player's HUD will briefly flash with blue and red lines, and the player will be surrounded by a red aura. A pulsing blue outline will envelop the player once shields begin to recharge.

Certain attacks can still deal damage even through shielding however, like status effects that will make the player bleed and take health damage even if shields are present, and  damage will simply bypass the player's shielding altogether.

Shields also receive no damage mitigation from armor and are significantly less effective at absorbing damage as a result, especially for well-armored Warframes. On the other hand, their regeneration makes them more useful for frames with high potential maximum shields but below-average potential maximum health such as Mag.

Apart from their natural regeneration, shields can be replenished using certain Warframe powers like Shield Polarize, and some units like Shield Ospreys can boost the maximum shields of other units within the vicinity, as well as remove the regeneration delay from taking damage.

Effects
Shields follow the Damage 2.0 system – they are simply a special type of hit points that can take increased or reduced damage based off the type of incoming damage. What differentiates them from health, though, is their recharge mechanic. There are two types of shields.

Shield
Warframes, as well as most lower-level Corpus enemies, use shields of a type simply called Shield. Shield-type shields, generally known as "normal shields", take increased or decreased damage against certain damage types according to the nearby chart. damage completely ignores normal shields, dealing damage directly to the health points underneath.

Proto Shield
Proto Shields are used by certain tougher Corpus enemies and by any bosses that employ shielding. Proto shields take increased or decreased damage against certain damage types according to the nearby chart. damage completely ignores proto shields as well.

Increasing Maximum Shields
A Warframe's maximum shield value increases after every few ranks, until rank 30 is reached. Beyond this, shields can only be enhanced by installing either Redirection, Vigor, or both if larger shield amounts are desired. A similar mod exists for Sentinels to increase their maximum shields: Calculated Redirection. Kubrows can instead be equipped with Link Shields, which increases their shields by a value based off the Warframe's maximum shields.

Missions may randomly have the cyrogenic leakage hazard present, which reduces the maximum shield capacity of all Warframes by half. Warm Coat can be equipped in anticipation of this random possibility in order to reduce the loss of shields, but it is not recommended.

Natural Recharge
Shields naturally recharge, but there is a 3-second recharge delay imposed whenever struck. Any incoming attacks within this timespan will reset the time needed to 3 seconds. Damage from proc effects like or  do not reset the delay timer. The delay timer is only reduced by the Quick Charge mod and only increased by Vital Systems Bypass, both of which can only be used in PvP.

Shields recharge at 15 units per second, plus 5% of the Warframe's maximum shields:

Note that because the recharge rate involves maximum shields, the shield recharge rate can be sped up by increasing maximum shield capacity. This shield recharge rate can be further boosted by Fast Deflection and Fortitude, which stack together as a multiplier to the original recharge rate.


 * With Fast Deflection at maximum rank, Mod Multiplier is 0.9.
 * With Fortitude at maximum rank, Mod Multiplier is 0.8.
 * With both mods installed at maximum rank, Mod Multiplier is 1.7.

Active Restoration
In the event of persistent enemy fire, a Warframe's shields may be hit too frequently for the natural regeneration to activate. In such cases shields can be restored via several alternative methods as listed below:


 * Items
 * Team Shield Restore is a beacon placed on the ground which restores 140 shields at 35 shields per pulse, over 4 pulses separated by 5 seconds each.
 * Medium Team Shield Restore is a beacon placed on the ground which restores 400 shields at 100 shields per pulse, over 4 pulses separated by 5 seconds each.
 * Large Team Shield Restore is a beacon placed on the ground which restores 1200 shields at 300 shields per pulse, over 4 pulses separated by 5 seconds each.
 * Shield Restore is a retired item (unavailable to acquire new ones, but still in the inventories of those who owned but never used them) that restores 150 shields.
 * Abilities
 * Trinity can restore the shields (and health) of all allied players and their companions within 50 meters (shown on the HUD as Tenno Affinity) with her Blessing ability.
 * With the Vampire Leech ability augment, Trinity's Energy Vampire pulses will restore shielding to other Tenno, provided the Tenno have full energy.
 * Mag can restore a percentage of maximum shielding to nearby players and companions with the Shield Polarize ability. She herself can gain additional shielding if the ability is augmented with Shield Transference.
 * Volt's Discharge, when augmented with Capacitance, confers shield to all friendly Tenno. The amount of shield restored is dependent upon the damage dealt by his ability.
 * Only in PvP, Volt can equip Recharge Barrier to make Electric Shield restore 100 shields to allies which run through it.
 * Companions
 * A Warframe's Shields can be automatically replenished by a Sentinel equipped with the Guardian mod, which will instantly recharge shields to full capacity whenever the shields are completely depleted. There is a substantial cooldown period before it can restore depleted shields again.
 * The Protect mod, exclusive to the Raksa Kubrow, works very much like the aforementioned Guardian ability.

Overshield
Overshield are extra shield points on top of the normal maximum shielding, which are acquired through the use of active shield restoration items or abilities that would restore shields beyond the Warframe's maximum shield capacity. Unlike normal shields, overshields do not regenerate, and instead stack on top of normal shielding, allowing even those with low maximum shield values to gain substantial shield defenses. Overshields have a maximum value of 1,200 regardless of source, and will remain for as long as the Warframe's shields do not drop to its normal maximum capacity. The player's shield counter changes from blue to purple while possessing overshields. Overshields can be obtained from:


 * Team Shield Restore
 * Medium Team Shield Restore
 * Large Team Shield Restore
 * Mag's Shield Transference
 * Trinity's Vampire Leech
 * Volt's Capacitance
 * Vazarin power Mending Tides, with Strengthen Defenses passive
 * Rakta Dark Dagger's effect
 * Shield Charger effect
 * Molecular Conversion effect

Enemy Shield Amounts
Each type of enemy has a base amount of maximum shielding, and this value (like for health and armor) increases by the level of that enemy. The scaling of enemy shields uses this formula:




 * Current Level is the actual level of the encountered enemy.
 * Base Level is the lowest level that the enemy can first appear. Elite Crewmen, for example, only appear in a mission if enemies are level 15+.
 * Base Shields is the value of shields the enemy has when at base level. Elite Crewman have 200 shields at level 15.

For example, the shield of a level 50 Elite Crewman is:



Trivia
Looking at how the shields function, with a good resistance towards puncture and slash damage, and a very bad resistance against impact damage, there is really only one way that they can possibly function. They can't be a stereotypical "shield", like a large flat sheet, as that would be better against impact damage. Therefore, they must function by coalescing energy around an object. This would be very effective against puncturing weaponry, like a bullet, as there is very little to deflect and thereby it wouldn't need to expend as much energy. This also explains why the shields are very good against slashing damage. They are still just shoving against a small area, and therefore they have little trouble. However, when they encounter something with a larger surface area, they can't deflect it as well, as they will have to coalesce much more energy to shove it away. Thereby, it's not that the shield is really "worse" at deflecting Impacts, it just has to expend more energy, making it less cost effective to deflect.