Shield (3.5e Creature Ability)

Shield (Ex or Su)
Shield is a protection unique to certain creatures, most of which are constructs. Summary::A shield defends the creature it envelopes and has the ability to soak damage of most any kind.

A shield is visible as a semi-opaque film of energy surrounding the protected target. Shields may be spherical, oblate or prolate - with or without geometric patterns - or nearly skin-tight, and can vary in colour depending on their energy source. While certain invisible shields exist, they are rare, and momentarily become visible when an attack is deflected or absorbed.

Shields that are technological in nature, such as those belonging to constructs are most often extraordinary abilities, whereas the shields of magical creatures and those granted by magic spells and items such as shield talismans are considered supernatural, and can be suppressed in an antimagic field.

As long as a shield has hit points remaining, any damage done to the protected creature is dealt to the shield instead. A shield can absorb damage of virtually any kind, from physical damage types (bludgeoning, piercing, slashing) to energy damage types (acid, cold, electricity and fire), to force damage, to even most typeless forms of damage. Shields are even effective against touch attacks. A shield can never absorb more damage than that it has hit points remaining, and any damage over that amount is dealt to the protected creature.

Only certain damage dealing effects can pass through a shield without being absorbed, such as a sonic effect, a gaze attack or psionic effects that allow a Will save, such as ultrablast. Line of sight and line of effect are unaffected by a personal shield. Nonstandard and conditional forms of damage such as from the reduced effect of a destruction spell or the corrosive effect of a rusting grasp aren't reduced by a shield.

An active shield with 1 or more hit points grants immunity to critical hits to any creature or object it protects.

Certain creatures and objects possess shields that protect an area around them. As long as the shield has hit points remaining, it stops objects and energy outside it from passing through, like a wall of force, decreasing its hit points by the appropriate amount. Objects and energy coming from inside the perimeter shield can pass through unimpeded. Effects that can pass through shields can also pass through perimeter shields (like sonic energy).

If the damage caused to the perimeter shield by an area effect breaks through it, the area effect may continue beyond the perimeter shield if the area permits; otherwise its expansion is stopped at the edge of perimeter shield. In the case of an area effect caused by an explosive effect, like a fireball or an acid flask, the explosive projectile detonates upon impact with the shield. Regardless, the center of an explosive effect lies outside the perimeter shield.

Attacks originating from outside the perimeter shield cannot directly target a creature inside it until the shield is down. Such attacks are resolved with the shield itself as the target. A perimeter shield has a base AC of 10 plus its deflection bonus, which is equal to the HD of the creature that projects it.

Perimeter shields are projected as a spherical field around their source. A perimeter shield does not extend into floors or walls. The radius of the shield is listed in the object or creature's description. When two perimeter shields protect the same area, their effects overlap.

A perimeter shield blocks line of effect for any effect that the shield stops, provided it has at least 1 hit point, but does not interfere with line of sight.

A few special creatures and objects have very powerful shields that can absorb a certain amount of damage from an attack without weakening, making even shields with a low amount of hit points hard to break through. These shields have a set hardness, subtracting that number from any damage the shield takes, to a minimum of 0. This particular property can be added to any type of shield.

Breakdown
How a shield works, what it stops, how strong it is and how quickly it comes back is governed by the following basic attributes.


 * Type: Normal (as written above), or any of the special types written below (Kinetic, Psionic, Spell, Fire, etc.).
 * Strength: Determines the amount of hit points the shield has. A shield with strength 5 has 5 hit points for every HD the creature or object projecting it has.
 * Hardness: How much damage a shield absorbs before it starts taking damage. A shield with hardness 5 that takes 13 points of damage from an incoming attack loses 8 of its hit points. A regular (non-hard) shield simply has the default hardness value of 0.
 * Range: How far the shield is projected from its source. A shield with range 30 protects anything within 30 feet of the object or creature projecting it. A regular (non-perimeter) shield simply has the default range of 0. A shield with a range above 0 projects a ward of 10 + the number of HD of the creature or object projecting it, that intercepts attacks aimed for creatures within its range.
 * Recharge Rate: How quickly lost shield hit points come back. The general rates are 1 hp/HD per hour (Very Slow), per 10 minutes (Slow), per minute (Default), or per round (Fast).

Example 1: Shield&mdash;Normal, strength 10, hardness 5, range 20-ft., Fast recharge.

This shield is a hard perimeter shield projected in a 20-foot-radius sphere with 10 hit points per HD and a hardness of 5, regaining hit points every round.

Example 2: Shield&mdash;Normal, strength 5.

This shield has 5 hit points per HD, and is default otherwise; hardness and range 0, with a normal (HD/minute) recharge rate.

Special Shield Types
Some forms of shielding have special properties. Specialized types of shields only block specific effects or specific forms of damage. A shield can have only a single specialized type.

Kinetic shields are shields that only stop high-speed physical projectiles. The stopping power of a kinetic shield is dependent on the speed of the object hitting it, providing a degree of deflection correspondent to the momentum of the object. The result is a shield that stops fast moving objects like weaponsfire but has no effects on slow moving objects, allowing the creature to interact with its environment without deflecting it.

Objects stopped by a kinetic shield include high speed objects and projectiles. Weapons such as handguns and rifles, cannons and particle beams are stopped, but lasers, energy effects and other massless or incorporeal weapons are not. Melee attacks are not stopped by a kinetic barrier, nor are slow-moving ranged attacks such as arrows or thrown projectiles.

Kinetic shields are a usual staple of science-fiction and are always extraordinary in nature.

Spell shields do not stop damage in the way normal shields do. Instead, they absorb incoming spells. Whenever a creature or object protected by a spell shield is targeted by a harmful spell, the spell is reduced to its base components upon touching the shield, converting it to raw energy that deals 5 damage to the shield per converted spell level. Spells that create area effects are only absorbed for the creature or within the area that a spell shield protects. If a creature with a personal shield has spell resistance, the spell shield takes effect against a spell only if the creature fails to resist it. Spells that do not allow spell resistance are not absorbed by a spell shield.

Spells absorbed by a spell shield deal 1 extra point of damage per spell level if the spellcaster has the Spell Penetration feat, and 2 extra points of damage per spell level if the spellcaster has the Greater Spell Penetration feat.

Damage dealt to a spell shield over its remaining hit points are not dealt to the protected creature. Instead, if the shield is a permanent ability, the shield maintains its negative hit points and remains down until its hit points are restored to positive values by the shield's natural recovery.

Spell shields are always supernatural in nature.

Psi-shields function the same way as spell shields do, except in that they absorb incoming psionic powers instead of spells. Powers that do not allow power resistance are not absorbed by a psi-shield.

Other Shield Types
Specialized shields exist for many purposes. Creatures that only need protection against a single type of effect do not need universal shields, that are usually prohibitively expensive, difficult to maintain and especially powerful. Possible types of shields specialized to a single group of effect types are listed below, complete with a summary of what they protect against and any further benefits they grant. All examples can be either extraordinary or supernatural, unless noted otherwise.


 * Heat Shields: Grants constant endure elements against high temperature effects, absorbs fire and heat damage.
 * Electromagnetic Shield: Absorbs electricity damage and turns away projectiles and small objects made of metal.
 * Psychic Shield : Absorbs mind-affecting effects in the same way a spell shield does. Supernatural abilities that create mind-affecting effects count as spells with an effective level equal to half the attacking creature's HD for the purpose of interacting with a psychic shield, rounded down.

Special
A creature with any type of inherent shield ability may benefit from the Augment Shielding feat, granting it 2 extra hit points per HD.