Okay, so I can make a bubble. What good is a bubble?
Force Shield was a relatively simple defensive Force maneuver also known as Protection Bubble. With this power, the user could create a nearly impenetrable semitransparent sphere around their body that could deflect or absorb attacks from blasters or lightsabers, and could block physical blows. In most cases, it could also prevent harmful Force powers from reaching its user. Usually, its use was regulated to only the latter action, but those skilled in its use or those whose ability in the Force was regulated mostly to it used the bubble of protection for a wide range of activities, due to its versatility.
Shields were fairly easy to use and usually did not require much concentration. Their size ranged anywhere from infinitesimal to gargantuan, though the latter took much more focus. Shields could be moved, fluctuated, or even regulated to let only certain things in and other things out. Despite this, the Force shield was not commonly used among the Jedi, as it was nearly replaced with the form-fitting Force Protection in most circles, and all other uses for it could be done with other Force powers. Those proficient in creating shields or limited to it were known as shieldmakers. Two known users were Cin Drallig and Zenethir Rodiron.
Force shields were always sphere-shaped, and could be nearly transparent to completely opaque, depending on the user's preference. The shield usually was of some color, though the color varied with the user's alignment or mood. The usual colors were green and blue. Shields ranged in size, but were usually meant to only cover the user and thus were fairly uniform in common use. When hit with energy, the part of the shield that was hit would turn white for a second before flickering back to its original color. This white flare always appeared, whether the user wished the shield transparent or not. When hit with a lightsaber, the white would appear as with a blaster bolt, but if the lightsaber remained pressed against the shield, it would spark and cause the user to expend more concentration to keep it up. The sparks would be accompanied by the sound of a regular lightsaber clashing with another. If a solid object, such as a slug or a grenade were to hit it, it would bounce off noiselessly.
Energy, clouds, and even poisonous fumes would roll over the shield, and heat or cold would be forced around it, keeping the temperature within the shield steady; with time, the shield's temperature would equal the body temperature of whatever the shield was protecting, making it stuffy to keep going for long periods of time. The shield could even keep air not already inside the shield out, if the user wished, but this was merely a preference.
With regular shieldmakers, the shields could block foreign Force powers from entering to harm what it was protecting, but, if the shieldmaker were adept enough, would allow certain Force powers in. It would do this by transferring the Force power to the shield itself, instead of the host. Put simply, Force Lightning would only hit the shield, Force Choke would only 'choke' the shield, and Force Heal would 'heal' the shield, causing no harm or change.
A shield could be shattered or caused to flicker out if an enemy had the power to do so, usually just by using a quick burst of Force Crush on the shield, causing it to implode. It completely dissipated after shattering, though the action would usually, though not always, cause pain to the user.
The shield itself was so versatile that even its power source could vary. It could come from the user's own power in the Force, absorb energy from whatever hit it to empower it, and even be powered by the user's own life force. However, the latter was incredibly risky, as it seriously endangered the life of the user should the shield be forcefully shattered. Even if the shield were only harmed it would cause pain to the shieldmaker, a pain that varied with the attack used.
Application and usage
The most common use for Force Shield was defense, though when used for self-protection, an alternative would be Force Protection. The shield could be used to protect the user, someone else, or practically anything the user would want to defend. In this capacity, the user had the choice of making the shield absorb any energy shot at or struck against it, or to have the shield reflect the energy, though this usually caused any blaster bolts to ricochet in an unpredictable direction. The defensive angle of the shield was fairly wide, from protecting an object from harm, or even to protecting entire fleets, though this was very consuming and the level of affinity and concentration of the user had to be extremely high. An experienced enough shieldmaker could make several shields to protect several things at once.
A less-thought of use of the defensive aspect of the Force Shield was its use to keep things from coming out of something or for continuing, from staying an avalanche to making a shield at the end of a blaster, causing the weapon to explode when fired. This was also used against lightsaber wielders, as a shield placed at the end of a lightsaber would cause a huge conflict of energy when the lightsaber was ignited, keeping the lightsaber from extending.
An adept shieldmaker could also, to make the shield form fitting, create hundreds of tiny shields that surrounded the thing it was to protect, but this was more difficult and was, in most cases, unnecessary. One could also make a shield that protected a moving thing by moving the shield at around the same pace as the occupant, but this was more difficult. As well, a kind of shield could be made so that only whatever the user desired could pass through. This went beyond Force powers to only allowing certain people or things to reach into and/or enter the shield.
Though not often thought of as an offensive Force technique, the Force Shield had several offensive uses. The first use was to cage the opponent/s in a shield to prevent their escape and their attack. A darker version of this was to decrease the size of the shield, either quickly or slowly, to crush whatever was inside. A variant of this was to encircle the victim's neck with several shields then move them in closer to choke them. Another use was to place a shield in the opponent's way, to cause the victim to smash into the shield or trip over it or to otherwise hinder their advance.
Shields could also be made to 'throw' at the target, causing an effect similar to using forceful telekinesis on rocks or boulders. If the target was fully capable of shattering the shields, the shield could but used to contain something so that, should the shield flicker out, the inertia would keep whatever was inside on a collision course towards the victim. The shields could also be used in this way to simulate or accentuate punches or kicks. A shield also could be used to encircle the target and lift it up into the air, then smashing it down against the ground, flickering out just in time to make the occupant feel the full force of the assault. Another dark use of the shield would be to create a shield inside the victim, then have it either quickly or slowly inflate, to cause the opponent to explode. This could also be used in the opponent's joints to cause them to dislocate.
A shield could also be used against blaster fire, or nearly any kind of ranged weapon strikes, if the shieldmaker did not have a lightsaber or wished to augment it. A shield could be created quickly to block the blaster bolt either by absorbing or deflecting it, and more experienced shieldmakers could reflect the bolt back at the attacker, though this required timing and expertise in moving the shield to the correct angle.
A more skilled and draining use of the shield was employed by the Shapeshifter Zenethir Rodiron, when aboard a ship of an early incarnation of the Rebel Alliance under attack. When told of Zenethir's knack for shields, the captain demanded that he be hooked up to the ship's mainframe in a way similar to the ship's realtime battle holoprojector. The Shapeshifter was instructed to watch the battle carefully and create stationary shields around enemy ships to cause them to run into them and explode, as well as place shields along the ends of the enemy's turbolaser batteries to cause them to explode when fired. This was extremely tiring and taxing, so that he could only do it for a few minutes before he was totally drained. As well, his photographic memory recalled every movement of every fighter during those few minutes, which overloaded his mind and caused temporary brain damage and memory loss.
The Force Shield could be used for many other activities that had nothing to do with battle. A shield could be used in place of telekinesis, for instance, though it wasn't as accurate. The shield could pick up an object and hold it within itself to be moved to wherever the user desired. It could also be used to flip switches, press buttons, and other menial tasks, such as propping open doors. As well, it could be used to create around oneself and use it to float, or doing the same thing to pass through lava or fire unharmed, or to move quickly through water by carrying the user within it, reducing the need to hold one's breath. If enough are created, shields could be used to make a bridge over such things as cliffs and rivers. They could also be used to start rockslides and create dams to block streams. It could also be placed within a wall, door, or device and quickly inflated, causing whatever it was in to explode, breaking equipment and making holes through walls. The uses of shields were virtually endless, limited only by the imagination of the user.
Despite the wide variety of uses for shields, there were several problems among its frequent practitioners. A somewhat common problem among Jedi proficient in only making shields was that they naturally could not create a shield around themselves, and were usually limited in using only Force Shield and perhaps one or two other minor Force powers. For some reason, some of them naturally also could not create a shield that blocked Force powers.
Behind the scenes
What could I do with a Force ball?
—Solus, while developing these techniques
The many uses for shields, mentioned above, were developed as a way for Zenethir Rodiron to use the Force while Solus was roleplaying him, but still limiting him to pretty much only that ability. These uses came about as a kind of substitute for normal Force powers. It is also a kind of 'What if?' extension of Protection Bubble.