Swarm (3.5e Subtype)

Swarm Subtype
Summary::A cooler swarm subtype that fixes some of the problems of the original.

A swarm is a collection of Tiny or smaller creatures (in other words, creatures that can share the same space as one another) that are individually totally insignificant but lethal when massed into a one collective group. A swarm acts and thinks as a single creature, possessing a single initiative modifier, a single speed, and a single Armor Class in addition to making saving throws as a single entity. In other ways, however, it acts as multiple separate creatures.

Traits
A swarm creature possesses the following traits (unless otherwise noted in a creature’s entry).


 * A swarm is not sized in the way that other creatures are; the size indicated in its stat block indicates the size of an individual member of the swarm, not the massed total. As such, swarms can only be made up of creatures of Tiny size or smaller, but always normally takes up at least a 10x10 ft. square (flying creatures take up a cube). Swarms size is dictated by Challenge Rating, simply adding more and more numbers to their ranks (see the table below for size of swarms by CR). No matter what its size, a swarm can share the same space with a creature of any size and move through spaces small enough to fit its component creatures.
 * Regardless of its size, a swarm has no reach. It never rolls attack rolls, and as such cannot make attacks of opportunity. A swarm’s only method of attack is to literally move into the same space as its foes, for which it never provokes attacks of opportunity.
 * A swarm can never be staggered or reduced to a dying state, and its hit point total is no longer wholly representative of its strength. Instead, each 5x5 section of the swarm has a number of hit points equal to the swarm’s maximum divided by the number of sections in the swarm (each square in a 10x10 swarm, for example, would possess one quarter of swarm’s maximum hit points); upon taking that amount of damage, the 5-foot section splinters off from the whole. When a section leaves, the maximum hit point total and the amount allocated to each other section of the swarm remain unchanged. A swarm that is vulnerable to weapon damage can also take non-lethal damage, but if separated by non-lethal damage it is capable of reforming again.
 * A swarm has no discernible anatomy of any kind. As a result, it immune to critical hits and cannot be flanked or surprised. A swarm made of Tiny creatures takes only damage damage from any attack or effect that requires an attack roll, while a swarm of Diminutive or smaller creatures takes only a quarter normal damage from those sources. Swarms are also subject to effects that create strong winds, since they are treated by such effects as being the size of their constituent creatures.


 * Swarm : A swarm deals 1d6 points of untyped damage per Hit Die it possesses to any creature that enters it space for any reason. The swarm deals 1d6 points of damage per HD to all within its space.
 * Communal Intellect: Even if the swarm’s type usually dictates that they are mindless, if it possesses this ability its congregated brainpower can sometimes grant them an Intelligence equal to their Challenge Rating divided by two, making them more on par with others of their kind.

Swarm Options
Swarms have multiple tactical options that they can make use of in battle in order to gain an edge on their opponents (see the description of each option below). A swarm that does not possess an Intelligence score may only make use of the “Adjust” option. An intelligent swarm can also use the “Condense” and “Expand” options. Using any of these options is a move action. Any movement incited by these options provoke attacks of opportunity normally.
 * Adjust: The swarm can freely adjust its dimensions as long as the total number of squares it occupies does not change.
 * Condense: The swarm shrinks its size down to the next lowest available size (so a 40x40 swarm would become 30x30); a 10x10 swarm becomes a 5x5 square. While in this state, the swarm deals double damage with its swarm ability, and both movement and visibility are limited to 5 feet (as a solid fog spell).
 * Expand: If the swarm expands, its swarm damage is reduced by half for the duration of the change, but its space is doubled.

Swarn Subtype Creatures
The following creatures have the Swarm subtype: