Overshield

Overshields are a Covenant technology that strengthens the Energy Shields of the user.

Function
The Overshield technology is used by the Covenant to enhance their Elite warriors' shields by a factor of three. In Halo 3, these Overshields only boost a player's shields to 200%. However it can also be used by any Spartan in MJOLNIR armor who might come upon it. When picked up, it takes approximately three seconds to completely charge, but during the charging period the player will be invincible. Once active the players normal shield does not take damage until the over shield is completely depleted (although any damage overlapping from something destroying the Overshield, for example a grenade's explosion, will also do damage to the players normal shield). If the Overshield is picked up when the players shield is below 100%, the player receives a full charge and the effects of the over shield stay. In the single player campaign the Overshield is reduced only when the player takes damager. In multiplayer it also gradually depletes over time.

Appearance
A glowing red (gold in Halo 2) orb of energy encased in a glass cube. In Halo 3 the orb appears to be held together by several small magnets. After walking over an Overshield, Master Chief's HUD shield display changes color from blue to red then green. Each color indicates one 'layer' of shields.

While wearing an Overshield in Halo 2 and Halo 3, the MJOLNIR armor is surrounded by a glowing force field which is easily seen even when wearing the Active Camouflage. This does not happen in Halo: Combat Evolved.

Advantages
Overshields effectively triple the strength of the MJOLNIR and Elite armor's shields. The shields can now protect the user from heavy weapons such as Rocket Launchers, Fuel Rod Cannons, Sniper Rifles and even a Plasma Grenade (not stuck). Also, as the shields are charging, you are immune to conventional means of damage, but you will still be killed by assassinations, falling, or the guardians.

Disadvantages
Due to the bright glow of the Overshields, the wearer is more easily visible. Also, the Overshields can be taken out completely by an overcharged Plasma Pistol shot. When the overshield takes damage, it takes more time for the shield to actually recharge. The shield also gradually loses energy, except if you are in campaign mode, a Juggernaut, VIP, or a Grifball carrier with them. Note: This glow does not appear in the Halo: Combat Evolved game.

Trivia

 * While picking up an Overshield, neither your energy shield or Overshield can be depleted until your Overshield fully charges.
 * In Halo: Ghosts of Onyx the force of Elites that assaults the Spartan team in the portal chamber are described as being equipped with Overshields, yet they seem to be just as easily killed as Elites with standard shields.
 * If you pick up an Overshield and walk over another before the first Overshield is fully charged, you will use up both Overshields but only receive the effect of one.