Z-4190 bubble shield

The Bubble Shield is an anti-artillery and personal defense device developed by the UNSC's Office of Naval Intelligence branch.

Overview
The Bubble Shield projects a transparent, slightly white/gold tinted protective sphere around the user. The shield itself is similar to a geodesic dome, made of tessellating hexagons. The shield protects against bullets, explosions, lasers, plasma, flames, grenades, and other projectiles used primarily by the Covenant. Vehicles and players however, are still able to pass through it. After exactly 20 seconds has passed it will collapse. Whether of Covenant or Human origin is unknown as there is little information and much speculation for both theories. Many point out that the Covenant Loyalists, mainly the Brutes, have been known to secure Human weapons and equipment for their own ends, thus pointing to the Bubble Shield as being one of Human development.

An early form of the Bubble Shield was used in the original teaser trailer for Halo 3. It is shown being used by Master Chief to protect him from an incoming Wraith mortar. In the video the Bubble Shield looked like a type of grenade leading to rumors that it would be one of the new grenade types.

Deployment
UNSC Marines are never seen deploying it during Campaign, while Brutes deploy it often. This leads it to be held as a Covenant Weapon and unlikely to be Human technology. At least one or two Brutes in a Covenant pack always have a Bubble Shield on hand. Brutes generally activate their Bubble Shields immediately when taking fire or feeling threatened. But on the other side of the side of this debate, marines are never seen using equipment. The Brutes could have obtained the Shield from dead marines (althought the marines are never seen using the shield).

Unlike the Heroic DLC "shield doors" vehicles are able to pass through the Bubble Shield. Once, inside, if the vehicle, or anything else then damages the shield generator itself on the enclosure of the bubble, the shield will then collapse on fired detonation. Upon reaching its energy limit Bubble Shields will make a high pitched sound prior to overloading and breaking.

Multiplayer Strategies
A great tip is to make sure your entire body is in the Bubble Shield and stick the very tip of your gun out that way you can return fire but you can't be hurt. The Bubble Shield is an incredibly useful piece of equipment in any Multiplayer game or match. These are a few yet vital tactics that you should know if you want to use the Bubble Shield to its full potential. If you have been in a close range fight with another player and your shields are down, it is often a good idea to use a Bubble Shield to give your shields time to recharge before you go frag your next victim. Also if you have a Shotgun or Energy Sword or a Gravity Hammer as your secondary weapon and a player with a regular weapon (Assault Rifle or Battle Rifle) is running to you, drop the shield so that they will be forced to come through the shield to finish you. Right before the player gets to the shield, pull out your Sword/Shotgun and blast them when they step through. If you do not have a close range weapon, use this same strategy except with a Frag or Spike Grenade. Time the grenade so that it will explode right as they step through while you step out the other side of the shield to avoid damage. Another good strategy is to throw a spike grenade into the bubble, the blast/spikes will be contained in the shield. The spikes will also fly and hit any player within the bubble causing massive amounts of damage even if it doesn't kill them outright but be ready with a weapon to finish off those that do survive the blast to quickly rack up the kills. This trick has been nicknamed by many "Halo" players the Shrapnel tactic.

Another method that is very useful is the Man Cannon Bubble Shield combo. In Valhalla and Narrows, campers often take position so that they can easily open fire at player landing from the Man Cannon. A player can use the Bubble Shield by sending it first, by throwing it onto the Man Cannon, thereby securing a safe landing zone on the other end of the Man Cannon protected from enemy fire and grenades. Also smart players can activate the Bubble Shield as they enter the Man Cannon, effectively giving them cover as they fly through the air. A good tactic against skilled snipers.

Also, you can start a fight inside, and before you die, toss a grenade (any type, preferably plasma grenades), and your weakened foe will die with you. A good way to kill someone in a Bubble Shield is with the Sniper Rifle. Make sure you are in a safe position so you don't get assassinated and aim at the player's head. This is quite easy because people usually don't move when they are in a shield. Keep it on the player's head and as soon as the shield disappears shoot them. While it may seem very simple, most players do not see this coming, and never expect it. Another fun way of getting through an opponent's Bubble Shield is to get a vehicle and drive into the player hiding in the shield. This works particularly well with a Warthog or Ghost and is very fun to watch as the victims believe that they are perfectly safe. Another strategy is to rush into the shield and step back right when you're in front of it, if it works the other player gets out of the shield, giving you an open shot. Also, it is possible to poke the barrel of a sniper rifle out of the shield while staying safely inside it yourself.

One strategy is, activating a Bubble Shield in a doorway so if you and your team were under fire they could use this shield to get away from the enemy. When an enemy is coming at you while you are in a Bubble Shield, throwing a grenade and moving out of the Bubble Shield depletes the enemy's shields so you can kill them with a single melee hit or headshot. Also, in close-quarters maps the Bubble Shield can cover an entire room for protection.

Another strategy is catch an opponent using heavy weapons by surprise by throwing a Bubble Shield in front of them as they fire. This calls for precise timing and close quarters. To pull off, a player must be within a reasonable close distance to the enemy and must deploy their Bubble Shield almost exactly as the enemy Rocket Launcher is fired. The activating Bubble Shield will cause the shot to explode in their face, often causing a suicide or giving the Bubble Shield deployer the kill.

One more strategy is to use the Bubble Shield as a trap. Lay the Bubble Shield near a hiding spot and wait for an enemy to use it. If they take the bait, kill them with a Shotgun or a different close range weapon. Another strategy that works but is hard to do and places the player at great risk of losing their own life is walking up to a Bubble Shield with either a Sniper or Battle Rifle then stopping right in front of the shield. If you are close enough then you can poke the end of the weapon through the shield and kill the player inside before they realize that you can. This works better with a Battle Rifle but is more dangerous as you have to be very precise but people expect it less to the extent you can often walk right up to the shield and as long as you don't enter they wont make a move until it's too late.

On some levels there is a glitch where Bubble Shields can be destroyed as they fall to the ground. Normally this is not possible as the shield protects the generator until it is fully deployed. However on some Multiplayer maps for example Valhalla (Level) it is possible to destroy the shield before it lands if aimed precisely and timed perfectly. This is a risky glitch as it is often seen more as a hack and also fails to work more times than it succeeds.

Campaign Strategies
When fighting large numbers of Brutes, the Bubble Shield is useful as it protects you from all sides. However, certain berserk Brutes can go inside the sphere and beat you down. It is particularly useful against Drones, partly because they usually surround you, and partly because they will almost never attempt to go inside the sphere. Do be aware, however, that after 19 seconds, the shield will deactivate, leaving you wide open to an attack. Another situation in which the Bubble Shield is useful is protecting you from a Scarab detonation. It will stop the explosion from harming you completely, unless the explosion starts on the inside of the Bubble Shield. So it is advised that you at least exit the Scarab before using the Bubble Shield. Beware that the Scarab's debris will fall through the Bubble Shield, however, and could kill you. Another strategy is to use a Bubble Shield as a stepping stone, breaking up combat and allowing the player to use the Bubble Shield to fall back on. This is especially useful at the end of The Storm, where there are large, linear sections.

A good tactic when enemy troops deploy a Bubble Shield is to "take over" their Bubble Shield. Charging into a Bubble Shield often catches Covenant troops off guard, and enemies wielding heavy weapons such as Fuel Rod Cannons or Brute Shots will not fire at such close range. Bubble Shielded enemies can easily be overpowered by melee or close ranged weapons as their teammates look on helplessly from outside.

Cons of the Bubble Shield

 * Enemies can walk in freely and kill you.
 * The shield does not stop enemy vehicles from entering.
 * You cannot return fire from inside the bubble's proximity.
 * The Bubble Shield only lasts a short 19 seconds. In combat, however, this is more than enough time to regroup and recover.
 * If either you or an enemy throws a grenade inside the Bubble Shield, it stays inside and will most likely kill almost everyone in the shield at the present time. Also, the grenade may detonate the Bubble Shield, increasing the damage, making it all the more dangerous to stay inside of it.
 * Flood Forms will usually and typically just run inside the Bubble Shield and attack you unlike other enemies who usually wait for it to disappear.
 * The generator is very delicate, so if you shoot at it from the inside, it will easily explode and destroy the bubble shield.
 * An easy way to destroy a Bubble Shield along with those in it is to use an explosive. This is done by quickly entering the shield, throwing a grenade inside (it'll most likely stick to you if thrown on the shield's wall) and quick exit before it detonates. Spike grenades work the best. The reason for this is the grenade's spikes, which bounce off the walls, doing more damage to a greater area, killing most inside the shield.
 * Most players will start a "staring contest," where they refuse to come in, and the person in the shield refuses to come out. Try to avoid this as the bubble shield will only last so long. In Team Games, players will often call for backup, getting another player to flank or jump in from a height, making it difficult to defend in the shield.
 * If an opponent has a Portable Gravity Lift equipment, they can throw it near the shield generator and force it to fly up, leaving anyone previously inside the shield defenseless... and annoyed. Anyone unaware of what had just happened is fairly easy to defeat, especially if it was thrown to gain a chance to recharge their shields.

Trivia

 * The original Bubble Shield was smaller than the finished Bubble shield, as seen in the Starry Night video. It stuck into the ground rather then just lay on top of the ground, it also was originally in grenade form and seemed more like a personal device.
 * In an early Beta Version of Halo 3 the Bubble Shield was able to roll like the Power Drain, did not glow gold, had orange lights, and was able to protect you against the turrets guarding the outer perimeter of the multiplayer map such as Snowbound. (This, however, changed when the game was released for gameplay reasons).
 * The Bubble Shield logo, along with the Trip Mine logo, is a Halo 3 multiplayer emblem.
 * There is debate as to whether it is an ONI weapon or a Covenant Brute weapon, since only Brutes are seen deploying them in campaign and it looks to be made out of Brute materials.
 * This shield resembles the description of the Onyx Sentinel shields in the Eric Nylund novel Ghosts of Onyx.
 * If you look closely at the Bubble Shield, you can see that there are actually two layers of shielding that make it up.
 * The Range of the Bubble Shield is close to three meters and can cover an entire Warthog.
 * A common strategy is to use short range weaponry in conjunction with the Bubble Shield. If they chase you inside, you will gain the upper hand easily by engaging them with weapons such as Shotguns, Gravity Hammer and Energy Swords.
 * When inside the Bubble Shield, a distinctive hum can be heard coming from the generator.
 * The Bubble Shield will make a static sound when shot by a rapid-fire or automatic weapons.
 * There is a glitch that if a Bubble Shield is placed on the lower deck of an Elephant on Sandtrap, the Spartan laser can then penetrate the shield.
 * You cannot actually disable a Bubble Shield by throwing a Power Drain at the generator, but you can leave the opponents inside vulnerable with drained health.
 * The Bubble Shield is movable by the use of gravity lifts.
 * With no damage modifiers, a melee with most weapons will destroy the shield generator.
 * The exterior design of the Bubble Shield looks very similar to that of the Regenerator.
 * In the machinima Red vs Blue, the Bubble Shield was agent South Dakota's armor ability.
 * If you throw a Power Drain into a Bubble Shield, the effects will be contained, but the glow will reach out.
 * The Bubble Shield actually works for 2 seconds before the animation.
 * McFarlane Toys has made a Bubble Shield in the 2009 Wave 1.
 * If you look closely at a bubble shield, you will see that it is pulsating slowly.
 * When activated at the right time the Bubble Shield can reflect large projectiles such as a Rocket Launcher missile.
 * in the popular video "Master Chief Sucks at Halo 3" the master chief thought the bubble shield was an impenetrable shield, and the user was hacking.

Images
 Image:Bubble Shield in Action.jpg|The Bubble Shield. Image:Bubbleshieldhud.svg|The Bubble Shield HUD icon. Image:Avatars_Halo_Halo3_Shield.jpg|The Bubble Shield activating in the Halo 3 trailer. Image:1179249572.jpg|The Bubble shield is capable of blocking practically all forms of attack throughout its duration, including Spartan Laser attacks. Image:Brute activates a bubble shield.jpg|A Brute activates a Bubble Shield. Image:Bubble shield Halo 3.jpg|A thrown bubble shield, about to activate itself. Note the way it "glows". 