Archives of Nethys

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All Rules in Creating Monsters

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Polymorphing

Source Alien Archive 2 pg. 141
Possibly one of the mightiest forms of transmutation magic, polymorphing allows you to change your shape (or the shape of a foe or ally) to that of another creature. You might polymorph into a different creature because you want to gain a measure of its power, or use a new shape to disguise yourself or just to place a foe at a disadvantage. All the galaxy’s creatures can serve as templates and starting points for a polymorphing spellcaster, but they aren’t the limit. Only your imagination and preparation limit the extent of your shapechanging powers.

The practice of polymorphing magic is common among those who revere Oras, as well as among the xenodruids who follow the Green Faith and the Xenowardens. Technomancers interested in biotech and life sciences also venture into the realm of shapechanging. Dreamers among Desna’s magicinclined followers likewise use polymorphing in order to create new shapes previously seen only in the mind’s eye for themselves and others.

Polymorph Rules

Source Alien Archive 2 pg. 141
Polymorph is a descriptor that applies to transmutation spells and effects that allow you to change the physical shape of yourself or another creature. A spell or effect with the polymorph descriptor has the following general parameters, unless the spell or effect specifies otherwise. As a rule, a polymorph spell or effect doesn’t change any attribute about its target unless it says it does.

A polymorph form has the shape and appearance of one base creature within limitations. A form grants other capabilities with limitations set by the version of polymorph spell you cast. A polymorph spell can rarely give the target all the capabilities of another creature. It can impart only traits of a physical nature, including changes in movement types, natural weapons, resistances, senses, and some other features. When the target takes the form of a specific individual, its capabilities are likely to be similar, but the magic can’t always grant the full extent of a creature’s power.

Forms

Source Alien Archive 2 pg. 141
When you change your own or another creature’s form using a spell with the polymorph descriptor, the target’s original form (referred to as its true form) is used to determine anything that is not explicitly changed by the spell.

When you learn a spell with the polymorph descriptor, you design a number of specific forms (as determined by the spell) known as polymorph forms. Each of these could be based on an extant creature, or they might be a product purely of your imagination. You can thereafter cast the spell to change yourself or another creature into one of your predetermined forms. These forms might be specific to you, each having a unique look that remains the same from one casting to the next (potentially even mimicking a specific individual), or they might be generic (so you use that form when you change into a creature, but the target’s appearance is different each time within the norms for that creature). You cannot, however, transform a target to have multiple forms at one time (so you couldn’t, for example, transform a single creature into a creature with the swarm subtype).

Multiple Effects

Source Alien Archive 2 pg. 142
Only one spell or effect with the polymorph descriptor can affect a creature at a time. If you’re the willing target of a polymorph effect while you’re polymorphed, the new effect changes your form and ends the older effect. While you are polymorphed, if you fail the saving throw against a polymorph effect for which you are an unwilling target, the new effect changes your form and ends the older effect. The same rules apply to a shapechanger currently in a shape provided by the change shape ability. A shapechanger can end a polymorph effect on itself by using its change shape ability to transform into another form allowed by that ability.

Appearance

Source Alien Archive 2 pg. 142
When a polymorph form is that of another creature, the target appears to be that creature. You decide at the time of designing a polymorph form if its appearance is generic (allowing the target to look like any general example of that type of creature, but never a specific creature) or specific (causing the target to always look like one specific individual that does not change between castings).

As a disguise, this change in appearance is perfect, granting the target a +10 bonus to Disguise checks (either to appear to be a typical version of a generic form or a specific individual when using a unique form). In addition, the DC of the target’s Disguise checks isn’t modified due to altering major features or disguising itself as a different race or creature type. The DC increase for disguising itself as a different size applies only if an observer knows its size is incongruous with the form. The GM can alter or eliminate the bonus to Disguise checks based on the target’s behavior, such as talking in animal form or other conduct outside the norm for a shape.

Equipment

Source Alien Archive 2 pg. 142
If the polymorph form granted by a spell is of the same creature type as the target’s true form, the armor, weapons, and other equipment the target had at the time of casting remain visible and accessible and are changed by the magic to be usable in the new form. If any item is out of the target’s possession for more than 1 round, it reverts to its normal form.

If the polymorph form is of a different creature type than the target’s true form, the spell causes the target’s armor (including any armor upgrades and the abilities of powered armor) to continue to function and be able to be activated by the target regardless of the character’s form. However, the armor isn’t visible in polymorph form, and it can’t be targeted or accessed (such as to change batteries) by either the target or other creatures. All other equipment is unavailable in a polymorph form of a different type and cannot be used, activated, targeted, or modified by either the target or other creatures.

Natural Attacks

Source Alien Archive 2 pg. 142
When you design a polymorph form, you can give it a natural attack. A creature in this form has an attack bonus for the natural attack equal to 1-1/2 times its character level or Challenge Rating (CR), to a maximum of three times the level of spell that grants the form. No ability modifiers, class features, feats, items, racial abilities, or spells modify this attack bonus (though it is affected normally by penalties). The natural attack deals damage equal to the standard melee damage for an expert NPC of a CR equal to the creature’s level or CR, to a maximum character level or CR equal to three times the level of spell that grants the form. No equipment modifies this damage except for Strength bonuses from personal upgrades (though it is affected normally by penalties).

Special Abilities

Source Alien Archive 2 pg. 142
Each version of a polymorph spell has a maximum CR. When you design a polymorph form, the target can gain the same maximum number of special abilities as an expert NPC of a CR equal to the spell’s maximum CR. Alternatively, if you base your form on a specific creature (which must be of a CR no higher than the spell’s maximum CR), you can select only abilities that the base form has, but you can select one ability more than the normal maximum.

All of these are in addition to any abilities gained from the polymorph form’s type or subtype (which are limited—see Type and Subtype), and they must be selected from the following list: amphibious, breath weapon, breathing, compression, defensive abilities, limited telepathy, racial traits, senses, and trample.

Breath Weapon: A breath weapon deals damage of one energy type of your choice, deals 1d4 damage of that type per character level or CR of the polymorphed target (to a maximum equal to the polymorph effect’s maximum CR), must be a line or cone (following the guidelines for the breath weapon universal creature rule), can be used only once every 4 rounds, and does one less d4 of damage each time it is used. When the damage reaches 0d4, the breath weapon no longer functions. A target can attempt a Reflex save (DC = 10 + half the polymorphed creature’s character level or CR or 10 + half the maximum CR of the polymorph effect, whichever is lower) to reduce the damage by half.

Breathing: When selecting breathing as a special ability, you can select one environment in which you are aware that living creatures can natively exist, and grant your polymorph form the ability to breathe in that specific environment. This can be underwater, in a specific toxic environment, or even in the void of space if you have first-hand knowledge of living creatures that successfully operate in a vacuum without needing to breathe. The target retains the ability to breathe as it normally does in addition to this benefit. Breathing can be an unimportant feature if the target retains its armor’s environmental protections (see Equipment).

Defensive Abilities: The limits of which defensive abilities you can select are outlined in each polymorph spell. You can select only one of the defensive options listed for the level at which you cast the spell, and it counts toward the maximum number of special abilities the form can grant.

Movement: Each polymorph spell or ability details what changes to movement, if any, your polymorph form can grant. Your polymorph form can grant one form of movement without it counting against its maximum number of special abilities, but any additional forms of movement must be selected as special abilities.

Racial Traits: When selecting a racial trait for a polymorph form, you can select any one player character racial trait of a race that grants such rules and that does not refer to or require any equipment, armor, armor upgrade, or drone upgrade to function. For example, you could select the exceptional vision trait of an android (gaining both low-light vision and darkvision), but not the upgrade slot ability (since it refers to armor upgrades). Additionally, the target can never gain racial ability adjustments, racial Hit Points, feats, or skill ranks from a polymorph spell’s effects. Each level of the polymorph spell has specific restrictions regarding spell-like abilities.

Senses: The limits of what senses you can select are outlined in each polymorph spell. Each of the sense options a given polymorph spell can grant the target counts as a single special ability that counts toward the maximum number of special abilities a polymorph form can grant.

Other Abilities: If you’re designing a polymorph form based on a specific creature, the GM may allow you to select one of that creature’s special abilities or traits so long as the creature has a CR no higher than the spell’s maximum CR. If a polymorph spell grants a trait that uses a base creature’s CR for a calculation, instead use the spell’s maximum CR or the polymorphed creature’s character level or CR, whichever is lower.

Some abilities should not be permitted by a GM. The target can’t gain an aura from a polymorph form. An ability can’t be gained if it requires more time to use than the polymorph spell’s duration. The target can’t gain any ability that makes it part of a communal mind or body, such as the barathu combine ability or the swarm mind ability that swarms have. In addition, the target can’t gain any special ability that allows it to summon or otherwise spawn other creatures. Because of how polymorph effects interact (per the Multiple Effects section), a polymorph spell can’t grant the target the change shape special ability, since the polymorph spell that granted the ability would end when the target used it. If an ability is supernatural or could harm the target in its use, the GM should be very cautious before allowing access to it in a polymorph form.

The weird magic of polymorph spells might grant the target the ability to cause other effects that should last longer than its transformation. If an effect the target creates while in a polymorph form has an ongoing duration when the target returns to normal form, the effect ends unless the GM decides otherwise. However, changes the target made that are not ongoing effects, such as the death of enemies the target fought, are permanent.

Size

Source Alien Archive 2 pg. 143
Some polymorph spells allow you to design a polymorph form of a specific size. If you change the target’s size, it gains the space and reach of the new size. Decide if the new form is tall or long and then use the space and reach rules from Table 8-1: Creature Size. If you try to polymorph the target into a size that the physical space it’s in can’t accommodate, the spell begins to take hold but then fails. You should also select a weight within the range indicated for that size on that table.

A target of a polymorph spell gains a minor bonus based on the size its new form provides, regardless of the target’s original size. Table 1 below shows these bonuses, which are enhancement bonuses to ability checks and skill checks based on the indicated ability score.

Table 1: Bonuses by Size

SizeBonus
DiminutiveDex +3
TinyDex +2
SmallDex +1
MediumStr +1
LargeStr +2
HugeStr +3

Type and Subtype

Source Alien Archive 2 pg. 144
Polymorph spells allow their target to appear to be a creature of a different type and subtype and grant the target some benefits related to the base creature’s capabilities. Despite these changes, the target’s type and subtype remain the same.

More powerful spells grant the target extra benefits based on the chosen type or subtype, as noted in the spell description. Those benefits follow. Taking the appearance of a type or subtype not listed below doesn’t grant the target any related abilities.

Construct

Changing a target that isn’t a construct into a constructed form grants it a +2 enhancement bonus to saving throws against disease, mind-affecting effects, necromancy effects, paralysis, poison, sleep, and stunning.

Elemental

Changing a target that doesn’t have the elemental subtype into an elemental form grants it a +2 enhancement bonus to saving throws against paralysis, poison, sleep, and stunning. The target is unflankable while in elemental form. A fire elemental form is immune to fire, vulnerable to cold, and cannot grant cold resistance.

Plant

Changing a target that isn’t a plant into a plant form grants it a +2 enhancement bonus to saving throws against mindaffecting effects, paralysis, poison, sleep, and stunning.

Undead

Changing a target that isn’t undead into an undead form grants it a +2 enhancement bonus to saving throws against mind-affecting effects, necromancy effects, paralysis, poison, sleep, and stunning.

Vermin

Changing a target that isn’t a vermin into a vermin form grants it a +4 enhancement bonus to saving throws against mind-affecting effects.

Initiative

Source Alien Archive 2 pg. 144
The target keeps its modifier to initiative. A polymorph form never changes this modifier.

Speed

Source Alien Archive 2 pg. 144
A polymorph spell can alter the target’s speed and movement types, as noted in the spell description. If the spell doesn’t, the target retains its normal speed and movement types.

Speech

Source Alien Archive 2 pg. 144
The target retains its speech capabilities while polymorphed unless you decide against that. The languages it speaks and understands don’t change with its shape.

Ability Scores

Source Alien Archive 2 pg. 144
While a polymorph form might grant the target enhancement bonuses to skill and ability checks based on its Strength and Dexterity, as detailed in Size, it never alters the target’s ability scores or ability modifiers.

Hit Points and Stamina Points

Source Alien Archive 2 pg. 144
The target retains its normal Hit Points and Stamina Points in your new form. A new form can’t grant it Hit Points or Stamina Points. Further, a form can provide no means for the target to regain Hit Points or Stamina Points or cause others to do so.

Resolve Points

Source Alien Archive 2 pg. 144
The target retains its normal Resolve Points. A new form can neither grant the target Resolve Points nor allow it special methods of regaining or granting others Resolve Points.

Features

Source Alien Archive 2 pg. 144
The target’s features from classes, themes, and so on still work in its new form. However, its form could limit the usage of features it has. Rely on common sense and GM guidance in such situations. Additionally, the target can’t gain class features, theme features, class grafts, and similar mechanical elements from a polymorph form. For instance, you can’t polymorph a target into an Aeon Guard to grant a target the benefits of that creature’s class graft, but you can transform a target to look like an Azlanti human.

Skills

Source Alien Archive 2 pg. 144
When in a polymorph form, the target retains its skills and its ranks in them. A form might grant the target modifiers to its skills or new ways to use them, but a form can’t grant the target new skills or skill ranks.

Spells

Source Alien Archive 2 pg. 144
The target can still cast spells while polymorphed. However, as with equipment, it might not be able to access or employ special materials to cast some spells. The GM may decide that while the target is polymorphed, its form prevents it from properly manipulating the materials required to cast a spell, such as the materials worth 1,000 credits per CR of an undead created with animate undead. In any case, a new form can’t grant the target the ability to cast spells. It can grant spell-like abilities, but only if those from a racial trait, and only one racial trait can be assigned to any given polymorphed form.