The universe is an endless expanse of adventuring potential. On its billions of worlds, physics create every possible permutation of geology, while life’s endless creativity gives rise to organisms both eerily familiar and defying imagination. Regardless of their design, all of these creatures struggle to survive and thrive in their native habitats, from icy seas and lush fungus jungles to the savage pyroclastic flows of tidally heated moons or the rusting hulks of ancient alien megastructures.
The following section contains rules to help you as GM adjudicate the game universe, including rules for the vastness of space, for various types of planets and the different terrains that may be found on them, and for environmental effects and hazards that may come into play in a variety of settings. Rules for settlements and structures both natural and artificial are presented at the end of the chapter.


The immeasurable gulf of space is home to everything on the Material Plane, housing more stars and planets than could ever be recorded. During their careers, the player characters will undoubtedly need to venture into space. Traveling from one planet to another, exiting the atmosphere of a planetoid, or visiting an orbiting space station are all examples of common travel that require at least a brief time in space. Many hazards of space can be mitigated by wearing armor (see page 196) or a standard space suit (see page 231), but sometimes unlucky spacefaring adventurers get caught without them!

Cosmic Rays

“Cosmic rays” is a catchall term for various interstellar radiation effects. They use the same rules as radiation (see page 403). Most habitable planets maintain atmospheres capable of repelling these emissions. Such protected planets allow, at most, a low amount of radiation in infrequent bursts. Planets devoid of a protective atmosphere are constantly assailed by radiation of medium to severe intensity.


The void of space is effectively empty of matter, and this vacuum is perhaps the greatest danger of outer space. A creature introduced to a vacuum immediately begins to suffocate (see Suffocation and Drowning on page 404) and takes 1d6 bludgeoning damage per round (no saving throw). Because a vacuum has no effective temperature, the void of outer space presents no dangers from cold temperatures. A creature retains its body heat for several hours in a vacuum. Sound doesn’t travel in a vacuum.
Decompression occurs when a creature suddenly transitions from a pressurized environment to a vacuum, such as by being flung out of an airlock or being inside a sealed structure that becomes heavily damaged. Such a creature takes 3d6 bludgeoning damage (no saving throw) in addition to any suffocation damage.
Most creatures travel the vacuum of space in a starship. For more information about starships, see page 292.

Astronomical Objects

Most living beings begin their lives on floating astronomical objects. These planets, planetoids, and stars are the hub of much adventure and vary in complexity of design and makeup. A brief summary of the different types of astronomical objects is presented below, along with various rules associated with each.

Classification of Astronomical Objects

There exist several different types of astronomical objects. Summarized below are the most prominent types encountered during interstellar exploration.


An asteroid is a fractured chunk of matter, notable for being too small to be considered a proper planetoid. Asteroids commonly lack any sort of ecosystem and are often bereft of an atmosphere and breathable air. Many see asteroids as exploitable resources, given that they are often rich in minerals of varying rarity.

Gas Giant

As their name suggests, gas giants are worlds composed entirely of gas—frequently elements such as hydrogen and helium. They lack any natural solid surfaces to walk on and so have no proper ground. Creatures unable to fly or without flight-capable equipment or magic tumble toward the dense core of the world at the falling speed of a standard-gravity planet. Such a fall often takes days, given the immense size of these worlds. Near the center of a gas giant, a creature is subject to extreme gravity (see page 402). The heart of a gas giant acts in many ways like a star (see Star below), including destroying creatures that don’t have full immunity to fire.

Irregular World

Some planets exist outside of the typical description of a (mostly) spherical mass of gases or silicate rocks and metals. These irregular worlds come in a variety of shapes, many of which are still considered theoretical. Some worlds might be artificially designed in the shape of a torus. Other worlds, like a planet in the form of a cube or a world that is entirely flat, exist as the result of cosmic abnormalities or the direct intervention of the divine.


Satellites are objects, such as moons, orbiting any other form of planetoid. “Satellite” is a classification that can be applied to other astronomical objects as well, as many asteroids and terrestrial worlds are also satellites. Unlike other types of astronomical objects, a satellite isn’t necessarily a natural object. Alien markers and space stations are but a few types of artificial constructs that hang in the gravitational field of planets. Some planets have only a single moon, while others (such as gas giants) boast dozens of objects caught in their gravitational fields.


A star—sometimes multiple stars—typically rests at the heart of a planetary system. Stars are massive balls of incandescent plasma that blast their orbiting planetoids with heat. While there are various categorizations of stars, from blue dwarf stars to yellow hypergiants, all stars produce enough heat to pose similar hazards to most adventurers. The surface of a star is so hot that only full immunity to fire allows a creature to survive there. Any creatures or items not immune to fire are instantly and utterly consumed down to the molecular level—only spells such as miracle or wish can bring back such victims.

Terrestrial World

Most people use the word “planet” to refer to a terrestrial world. The ones closest to the star of a solar system are the worlds most likely to be naturally habitable. They’re home to varying ecosystems, from barren, rocky landscapes to vibrant jungles of lush plant life and rushing waterways. Such worlds are sometimes categorized by their predominant features, leading to titles such as desert world, ice world, jungle world, and lava world.


Strange Atmospheres

Though it happens rarely, some astronomical objects have atmospheres that seem to defy the laws of reality—usually due to magical interference or technology run amok. Sometimes these atmospheres are infused with a certain type of energy. Such atmospheres function like corrosive atmospheres, except they deal damage of the appropriate energy type (electricity, fire, sonic, etc.).

An atmosphere is a layer of gases held in place by the pull of a planetoid’s gravity. The gravity and temperature of a planetoid impact its ability to retain an atmosphere. Most planets and planetoids support some manner of atmosphere. In addition to hospitable atmospheres, there are various other types of atmosphere that serve as hazards to most life.


As the name suggests, a corrosive atmosphere eats away at matter. The type and speed of the erosion varies, but the most common use of this term describes atmospheres capable of dissolving most matter. A typical corrosive atmosphere deals anywhere from 1 acid damage per minute up to 10d6 acid damage per round to creatures and objects within. Certain metals and treated materials may be immune to the specific atmosphere of a planet, and often the corrosion can be mitigated with dutiful preparation.

No Atmosphere

A creature on a planet without an atmosphere (or with an atmosphere so thin that it is effectively airless) is exposed to a vacuum (see page 394).


A normal atmosphere is one that can support the majority of breathing life-forms. Most such atmospheres are composed of some combination of oxygen, nitrogen, and other nontoxic gases.


A nonacclimated creature operating in a thick atmosphere treats it as somewhat harmful, due to the extra chemical compounds in the air and the increased atmospheric pressure. Every hour, such a creature must succeed at a Fortitude save (DC = 15 + 1 per previous check) or become sickened. This condition ends when the creature returns to a normal atmosphere. Conversely, the increased weight of the air grants a +4 circumstance bonus to Acrobatics checks to fly or Piloting checks to keep an aircraft in flight.
Severely thick atmospheres are far more dangerous. Every minute, a creature in such an atmosphere must succeed at a Fortitude save (DC = 15 + 1 per previous check) or begin to suffocate (see Suffocation and Drowning on page 404) as its lungs cease coping with the density of the oxygen inhaled and lose the strength to keep pumping air into its bloodstream.


Thinner atmospheres tend to cause a nonacclimated creature to have difficulty breathing and become extremely tired. A typical thin atmosphere requires such a creature to succeed at a Fortitude save each hour (DC = 15 +1 per previous check) or become fatigued. The fatigue ends when the creature returns to a normal atmosphere.
Severely thin atmospheres can cause long-term oxygen deprivation to those affected in addition to the effects of a standard thin atmosphere. The first time a creature in a severely thin atmosphere fails its Fortitude save, it must succeed at a DC 25 Fortitude save or take 1 damage to all ability scores. A creature acclimated to high altitude (see Hill and Mountain Terrain on page 397) gains a +4 insight bonus to its saving throw to resist this effect.


Toxic atmospheres are composed of poisonous compounds and vary radically in their consistencies. Some toxic atmospheres are capable of sustaining oxygen-breathing life-forms, while others immediately suffocate those within them. Regardless of whether or not they allow creatures to breathe, toxic atmospheres are threats to most living creatures, as they act as an inhaled poison (see page 417). Though the specific type of poison varies, many toxic atmospheres act as existing poisons but with radically different onset times and save DCs. Low-level toxic atmospheres can have onset times measured in hours or days, while heavily toxic atmospheres have onset times measured in rounds.


The following section includes information on a variety of biomes found on planets. Some planets could be entirely made up of a single biome, such as desert or forest worlds, while other planets contain a mix of the following terrain types.

Aerial Terrain

On worlds where the atmosphere expands high above the physical boundaries of the surface, there exists a region of open air. Similarly, gas giants are made up of nothing more than a vast atmosphere, held in place by a starlike core. The most common rules sections to reference when using aerial terrain are Falling (see page 400), Gravity (see page 401), Suffocation and Drowning (see page 404), and Weather (see page 398). The rules for flying with the Acrobatics skill are also critical for many creatures operating in an aerial environment.


Most clouds are little more than condensed gas that obfuscates vision. Treat a cloud in an aerial environment using the same rules as fog cloud, except it’s a nonmagical effect. Other types of cloud exist, such as corrosive or toxic clouds, which operate in the same manner as those types of atmospheres (see above).

Stealth and Detection in Aerial Terrain

How far a character can see in the air depends on the presence or absence of clouds. Creatures can usually see 5d8x100 feet if the sky is completely clear, with minimal clouds (or other aerial objects) blocking their views. Clouds generally provide enough concealment to hide within (though the hiding creature might have difficulty seeing out from its hiding place).

Aquatic Terrain

Aquatic terrain can be one of the least hospitable to PCs because most can’t breathe underwater. The ocean floor holds many marvels, including undersea analogues of any of the other terrain elements described in this chapter, but if characters find themselves in the water because they were bull-rushed off the back of a transport ship, the kelp beds or volcanic vents hundreds of feet below them don’t matter. The most common rules sections to reference when using aquatic terrain are Suffocation and Drowning (see page 404) and Underwater Combat (see page 405). The rules for swimming with the Athletics skill (see page 137) are also critical for many creatures operating in an aquatic environment.

Deep Water

Lakes and oceans simply require a swim speed or successful Athletics checks to move through (typically, DC 10 in calm water, DC 15 in rough water, DC 20 in stormy water, and DC 30 in maelstrom water). Characters need a way to breathe if they’re underwater; lacking that, they risk drowning. When underwater, characters can move in any direction, including up and down.

Extreme Depths

At certain depths, the pressure of the surrounding water becomes so great that characters might be affected as if they were in a thick or severely thick atmosphere (see page 396), even if they can breathe underwater.

Stealth and Detection Underwater

How far a character can see underwater depends on the water’s clarity. As a guideline, creatures can see 4d8×100 feet if the water is clear and 1d8×10 feet in murky water. Running water is always murky, unless it’s in a particularly large, slow-moving river. It is hard to find cover or concealment to hide underwater (except along the sea floor).

Desert Terrain

Desert terrain exists in cold, temperate, and warm climates, but all deserts share one common trait: very little precipitation. The three categories of desert terrain are tundra (cold desert), rocky deserts (often temperate), and sandy deserts (often warm). The most common rules sections to reference for adventures in these areas are Cold Dangers (see page 400), Heat Dangers (see page 402), Starvation and Thirst (see page 404), and Weather (see page 398).

Stealth and Detection in the Desert

In general, the maximum distance in desert terrain at which a creature can succeed at a Perception check to detect the presence of others is 6d6x20 feet; beyond this distance, elevation changes and heat distortion in warm deserts makes sight-based Perception checks impossible. The presence of dunes in sandy deserts limits spotting distance to 6d6x10 feet. The scarcity of undergrowth or other elements that offer concealment or cover makes using Stealth more difficult.

Forest Terrain

A forest can be composed of more than trees. On some worlds, vast fungal growths tower into the sky, while on others metallic veins rise from the ground and connect in spidery canopies. Common rules sections to reference for forests are Catching on Fire (see page 403), Falling Objects (see page 401), Smoke Effects (see page 404), and Vision and Light (see page 261).


Most forests are filled with trees, or something akin to trees, which provide partial cover to those standing in the same square as a tree. An average tree has an AC of 4, a hardness of 5, and 150 HP (see page 409 for rules on smashing an object). A successful DC 15 Athletics check is enough to climb most trees.


Fungal blooms, vines, roots, and short bushes cover much of the ground in a forest. Undergrowth counts as difficult terrain (see page 257), provides concealment (20% miss chance), and increases the DCs of Acrobatics and Stealth checks by 2. Squares with undergrowth are often clustered together. Undergrowth and trees aren’t mutually exclusive; it’s common for a 5-foot square to have both a tree and undergrowth.

Stealth and Detection in a Forest

In a sparse forest, the maximum distance at which a creature can succeed at a Perception check to detect the presence of others is 3d6×10 feet. In a medium forest, this distance is 2d8×10 feet, and in a dense forest it is 2d6×10 feet.
Because any square with undergrowth provides concealment, it’s usually easy for a creature to use the Stealth skill to hide. Logs and massive trees provide cover, which also makes hiding possible.
The background noise of a forest makes Perception checks that rely on sound more difficult, increasing the DC of the check by 2 (not 1) per 10 feet.

Hill and Mountain Terrain

Hill terrain describes rises in the immediate area, often multiple hills spread over miles. This type of terrain can occur in any other biome. Mountains are steeply rising rock, metal, or even the organic crust of the planet. The most common rules sections to reference when using hill and mountain terrain are Cold Dangers (see page 400), Falling (see page 400), and Weather (see page 398).


Usually formed by natural geological processes, chasms are common dangers in mountainous areas. Chasms aren’t hidden, so characters won’t (usually) fall into them by accident. A typical chasm is 2d4×10 feet deep, at least 20 feet long, and anywhere from 5 to 20 feet wide. It usually requires a successful DC 15 Athletics check to climb the wall of a chasm. In mountain terrain, chasms are typically 2d8×10 feet deep.

Rock Wall

A vertical plane of stone, a rock wall requires one or more successful DC 25 Athletics checks to ascend. A typical rock wall is from 2d4×10 feet tall to 2d8×10 feet tall.

High Altitude

At particularly high altitudes, the thinning atmosphere poses a challenge for many creatures, with the same effects as a thin atmosphere (see page 396). A creature residing at a high altitude for 1 month becomes acclimated and no longer takes these penalties, but it loses this benefit if it spends more than 2 months away from high-altitude terrain and must reacclimatize upon returning.

Stealth and Detection in Hills and Mountains

As a guideline, the maximum distance in mountain terrain at which a creature can succeed at a Perception check to detect the presence of others is 4d10×10 feet. In hill terrain, the maximum distance is 2d10×10 feet. It’s easier to hear distant sounds in the mountains. The DCs of Perception checks that rely on sound increase by 1 per 20 feet between listener and source, not 1 per 10 feet.

Marsh Terrain

Two categories of marsh exist: relatively dry moors and watery swamps. Both are often bordered by lakes (see page 396), which are effectively a third category of terrain found in marshes. The most common rules sections to reference for marshes and swamps are Suffocation and Drowning (see page 404), Underwater Combat (see page 405), and Weather (see below).


If a square is part of a shallow bog, it has deep mud or standing water of about 1 foot in depth. It counts as difficult terrain, and the DCs of Acrobatics checks attempted in such a square increase by 2.
A square that is part of a deep bog has roughly 4 feet of standing water. It counts as difficult terrain, and Medium or larger creatures must spend 4 squares of movement to move into a square with a deep bog, or characters can swim if they wish. Small or smaller creatures must swim to move through a deep bog. Tumbling is impossible in a deep bog.
The water in a deep bog provides cover for Medium or larger creatures. Smaller creatures gain improved cover. Medium or larger creatures can crouch as a move action to gain this improved cover. A creature with this improved cover takes a –10 penalty to attacks against creatures that aren’t underwater. Deep bog squares are usually clustered together and surrounded by an irregular ring of shallow bog squares.

Stealth and Detection in a Marsh

In a moor, the maximum distance at which a creature can succeed at a Perception check to detect the presence of others is 6d6×10 feet. In a swamp, this distance is 2d8×10 feet. Vegetation and deep bogs provide plentiful concealment (20% miss chance), so it is possible to use Stealth to hide in a marsh.

Urban Terrain

Urban terrain can be found in most settlements where the people have greatly exerted their influence over the surrounding environment, constructing buildings where they can live and work in comfort and laying well-defined roads, usually paved. This type of terrain can occur in just about any biome, and it often supersedes the environmental effects of that biome. Urban terrain can include space stations, and it is often replete with technology. The most common rules sections to reference when using urban terrain are Settlements (see page 405), Structures (see page 406), and Vehicles (see page 228), as well as Breaking Objects (see page 409) and sometimes Radiation (see page 403).

Stealth and Detection in Urban Terrain

In a settlement with wide, open streets, the maximum distance at which a creature can succeed at a Perception check to detect the presence of others is 2d6×10 feet. In a settlement where the buildings are more crowded, standing close together, this distance is 1d6×10 feet. The presence of crowds might reduce this distance.
Thanks to twisting side streets and vehicles that can provide cover, it’s usually easy for a creature to use Stealth to hide in a settlement. In addition, settlements are often noisy, making Perception checks that rely on sound more difficult; this increases the DC of any such checks by 2 per 10 feet.


Weather can play an important role in an adventure. The following section describes weather common on most habitable worlds. Additional rules for cold and heat dangers can be found in Environmental Rules starting on page 400.

Rain and Snow

Bad weather frequently slows or halts travel and makes it virtually impossible to navigate from one spot to another. Torrential downpours and blizzards obscure vision as effectively as dense fog. Most precipitation is rain, but in cold conditions it can manifest as snow, sleet, or hail. If the temperature drops from above freezing to 32° F or below, it might produce ice.


Rain reduces visibility ranges by half, resulting in a –4 penalty to Perception checks. It has the same effect on flames and Perception checks as severe wind (see below).


Falling snow has the same effects on visibility and skill checks as rain. Snow-covered squares count as difficult terrain. A day of snowfall leaves 1d6 inches of snow on the ground.

Heavy Snow

Heavy snow has the same effects as normal snowfall but also restricts visibility as fog does (see Fog below). A day of heavy snow leaves 1d4 feet of snow on the ground. Snow at this depth counts as difficult terrain, and it costs 4 squares of movement to enter a square covered with heavy snow. Heavy snow accompanied by strong or severe winds might result in snowdrifts 1d4×5 feet deep, especially in and around objects big enough to deflect the wind—a reinforced wall or a large force field, for instance. There’s a 10% chance that a heavy snowfall is accompanied by lightning (see Thunderstorm on page 399).

Other Precipitation

There are other forms of precipitation, such as freezing rain, hail, and sleet. These generally function as rain when falling, but at the GM’s discretion, they may also have effects on movement similar to snow once they accumulate on the ground.


The combined effects of precipitation (or dust) and wind that accompany storms reduce visibility ranges by three-quarters, imposing a –8 penalty to Perception checks. Storms make aiming with ranged weapons difficult, imposing a –2 penalty to attack rolls, and archaic ranged weapons can’t be fired at all. Storms automatically extinguish unprotected flames. Storms commonly appear in three types: dust, snow, or thunder.

Dust Storm

These desert storms differ from other storms in that they have no precipitation. Instead, a dust storm blows fine grains of sand that obscure vision, smother unprotected flames, and can even choke protected flames (50% chance). Most dust storms are accompanied by severe winds and leave behind a deposit of 1d6 inches of sand. There is a 10% chance for a dust storm to be accompanied by windstorm-magnitude winds (see Table 11–6: Wind Effects on page 400); this greater dust storm deals 1d3 nonlethal damage each round to anyone caught out in the open without shelter and also poses a choking hazard (see Suffocation and Drowning on page 404). A greater dust storm leaves 2d3–1 feet of fine sand in its wake.


In addition to the wind and precipitation common to other types of storms, a snowstorm leaves 1d6 inches of snow on the ground afterward.


In addition to wind and precipitation, a thunderstorm is accompanied by lightning that can pose a hazard to characters who don’t have proper shelter (especially those in metal armor). As a rule of thumb, assume one bolt per minute for a 1-hour period at the center of the storm (GM rolls to hit). Each bolt deals between 4d8 and 10d8 electricity damage. One in 10 thunderstorms is accompanied by a tornado.

Powerful Storms

Very high winds and torrential precipitation reduce visibility to zero, making Perception checks and all ranged weapon attacks impossible. Powerful storms are divided into the following types.


Whether in the form of a low-lying cloud or a mist rising from the ground, fog obscures all sight beyond 5 feet, including darkvision. Creatures 5 feet away have concealment (20% miss chance).


Wind can create a stinging spray of dust, sand, or water, fan a large fire, rock an atmospheric transport midflight, and blow gases or vapors away. If powerful enough, it can even interfere with some ranged attacks and knock characters down. Below are the most common wind forces seen on habitable worlds.

Light Wind

A gentle breeze, having little or no game effect.

Moderate Wind

A steady wind often extinguishing small, unprotected flames.

Strong Wind

Gusts that automatically put out any unprotected flames. Such gusts impose a –2 penalty to nonenergy ranged weapon attack rolls.

Severe Wind

Nonenergy ranged weapon attack rolls take a –4 penalty.


Powerful enough to bring down branches, if not whole trees. Nonenergy ranged weapon attack rolls take a –4 penalty, while attacks with archaic ranged weapons are impossible. Perception checks that rely on sound take a –8 penalty due to the howling of the wind. Small characters might be knocked down.

Hurricane-Force Wind

Nonenergy ranged weapon attack rolls take a –8 penalty, and archaic ranged weapon attacks are impossible. Perception checks based on sound are impossible: all characters can hear is the roaring of the wind. Hurricane-force winds often fell trees. Most characters are knocked down due to the force of these winds.


All flames are extinguished. All nonenergy ranged weapon attacks are impossible, as are sound-based Perception checks. A creature in close proximity to a tornado that fails a DC 15 Strength check is sucked toward the tornado. All creatures that come into contact with the actual funnel cloud are picked up and whirled around for 1d10 rounds, taking 6d6 bludgeoning damage per round, before being violently expelled in a random direction (falling damage, described below, might apply). While a tornado’s rotational speed can be as great as 300 mph, the funnel itself moves forward at an average of 30 mph (roughly 250 feet per round). A tornado uproots trees, destroys buildings, and causes similar forms of major destruction.

Table 11-6: Wind Effects

Light0–10 mph
Moderate11–20 mph
Strong21–30 mph–2
Severe31–50 mph–4
Windstorm51–74 mph–4
Hurricane75–174 mph–8
Tornado175–300 mphImpossible

* This applies only to nonenergy ranged weapons. Larger weapons, such as starship weapons, ignore this penalty.

Environmental Rules

The following is a compilation of rules appropriate for use in a variety of environments.

Cold Dangers

Cold and exposure deal nonlethal damage to the victim. A character can’t recover from the damage dealt by a cold environment until she gets out of the cold and warms up again.
An unprotected character in cold weather (below 40° F) must succeed at a Fortitude save each hour (DC = 15 + 1 per previous check) or take 1d6 nonlethal cold damage. A character can attempt Survival skill checks to gain a bonus to this saving throw and might be able to apply this bonus to other characters as well (see page 148).
In conditions of severe cold (below 0° F), an unprotected character must succeed at a Fortitude save every 10 minutes (DC = 15 + 1 per previous check) or take 1d6 nonlethal cold damage. A character can attempt Survival skill checks to gain a bonus to this saving throw and might be able to apply this bonus to other characters as well.
Extreme cold (below –20° F) deals 1d6 lethal cold damage per minute (no saving throw). In addition, a character must succeed at a Fortitude save (DC = 15 + 1 per previous check) each minute or take 1d4 nonlethal cold damage. Colder environments can deal more damage at the GM’s discretion.
A character who takes any damage from cold or exposure is beset by frostbite or hypothermia (same as fatigued). These penalties end when the character recovers the nonlethal damage she took from the cold and exposure.


Icy surfaces count as difficult terrain, and the DCs for Acrobatics checks attempted on ice increase by 5. Characters in prolonged contact with ice might run the risk of taking damage from severe cold.


A character that falls takes 1d6 damage per 10 feet fallen, to a maximum of 20d6. A character that takes damage from a fall lands prone.
If a character deliberately jumps instead of merely slipping or falling, the damage is the same but the first 1d6 is nonlethal damage. On a successful DC 15 Acrobatics check, the character avoids taking damage from the first 10 feet fallen and converts the damage from the second 10 feet to nonlethal damage. For example, a character who slips from a ledge 30 feet up takes 3d6 damage. If the same character deliberately jumps, he takes 1d6 nonlethal damage and 2d6 lethal damage. And if the character leaps down with a successful DC 15 Acrobatics check, he takes only 1d6 nonlethal damage and 1d6 lethal damage from the plunge.
The damage from the first 10 feet of a fall onto a yielding surface (such as soft ground or mud) is converted into nonlethal damage. This conversion is cumulative with damage reduced through deliberate jumps and successful Acrobatics checks.
A character can’t cast a spell or activate an item while free-falling unless the fall is greater than 500 feet or the spell or item can be used as a reaction. Casting teleport or a similar spell while falling doesn’t end the character’s momentum; it just changes her location, meaning that she still takes falling damage, even if she arrives atop a solid surface.

Falling and Gravity

The rules for falling presented here assume standard gravity. For planets with high or low gravity, double or halve the damage amounts, respectively. Falling in extreme gravity deals as least triple the listed damage, and potentially even more.

Falling into Water

Falls into water are handled somewhat differently. If the water is at least 10 feet deep, a falling character takes no damage for the first 20 feet fallen and 1d3 nonlethal damage per 10-foot increment for the next 20 feet fallen. Beyond that, falling damage is lethal damage as normal (1d6 per additional 10-foot increment).
A character who deliberately dives into water takes no damage with a successful DC 15 Athletics check or DC 15 Acrobatics check, as long as the water is at least 10 feet deep for every 30 feet fallen. The DC of the check increases by 5 for every 50 feet of the dive.

Falling Objects

Just as characters take damage when they fall more than 10 feet, so too do they take damage when they are hit by falling objects.
An object that falls upon a character deals damage based on its size and the distance it fell. Table 11–7: Damage from Falling Objects determines the amount of damage dealt by an object based on its size. Note that this assumes the object is made of dense, heavy material, such as metal or stone. Objects made of lighter materials might deal as little as half the listed damage, subject to the GM’s discretion. For example, a Huge boulder that hits a character deals 6d6 bludgeoning damage, whereas a Huge wooden wagon might deal 3d6 bludgeoning damage. In addition, if an object falls less than 30 feet, it deals half the listed damage. If an object falls more than 150 feet, it deals double the listed damage. Note that a falling object takes the same amount of damage as it deals.
Dropping an object on a creature requires a ranged attack against its KAC. Such attacks generally have a range increment of 20 feet. If an object falls on a character (instead of being thrown), that character can attempt a DC 15 Reflex save to take half damage if he is aware of the object. Falling objects that are part of a trap use the trap rules (see page 410) instead of these general guidelines.

Table 11-7: Damage from Falling Objects

Tiny or smaller1d6


Gravitational differences between planets have the potential to cripple characters or make them superheroes—and sometimes both at the same time. Most planets habitable by humanoids have a gravity level defined as standard, which makes them similar enough that trying to arbitrate the difference isn’t necessary. Others, however, require special consideration. For planets with gravities that aren’t quite standard but don’t fall into the exact categories below, the GM might decide to assume the effects are proportional. For example, a planet with half standard gravity allows player characters to jump twice as high, whereas one with 1-1/2 standard gravity cuts jump heights by a third. In all cases, these effects last until the PCs adjust to the gravity (a process that typically takes about a month of living under such conditions). See Flying on page 259 for information about flying on planets with high or low gravity.

Extreme Gravity

A planet where the gravity is at least five times as strong as standard gravity is extremely dangerous to most creatures. In addition to the limitations of high gravity (see below), a creature in this environment takes an amount of nonlethal bludgeoning damage per round (at least 1d6, but potentially more, depending on the intensity of the gravity). Once a character takes sufficient nonlethal damage to be reduced to 0 Hit Points, any further damage from extreme gravity is lethal bludgeoning damage.

High Gravity

On high-gravity worlds, characters are burdened by their increased weight, and their physical abilities are affected accordingly. On a high-gravity world, where the gravity is at least twice as strong as standard gravity, a character (and her gear) weighs twice as much as on a standard-gravity world, but she has the same amount of strength. Such characters move at half speed, can jump only half as high or as far, and can lift only half as much. Thrown weapons (though not those of natives) have their ranges cut in half as they fall to the ground more rapidly. Modifications to running, jumping, and lifting can be negated by certain magic or technology, but projectiles remain affected. Characters who remain in a high-gravity environment for long periods (more than a day) often become fatigued and remain so until they leave the planet or become accustomed to the gravity.

Low Gravity

Low-gravity worlds are liberating to most species acclimated to standard-gravity worlds. Such characters’ muscles are far more effective than normal. On a low-gravity world, where the gravity is no greater than a third of standard gravity, PCs can jump three times as high and as far and lift three times as much. (Movement speed, however, stays the same, as moving in great bounds is awkward and difficult to control.) Thrown weapons have their range categories tripled.


Standard-gravity worlds have gravity approximately the same as that of lost Golarion, which is identical to Earth’s gravity.

Zero Gravity

Movement in zero gravity (also referred to as zero-g) is not the same as flight. Controlled movement is difficult without some form of propulsion, and creatures without something to push off from often find themselves floating aimlessly. A creature in a zero-gravity environment can’t take move actions to move its speed, crawl, or take a guarded step. If a creature is adjacent to or in the same square as an object (including a wall, floor, or ceiling) or another creature one size category smaller than itself or larger, it can take a move action to push off that object or creature, moving at half its land speed in a direction of its choosing (as appropriate); if that object or creature is movable, it begins moving in the opposite direction at that same speed.

Heat Dangers

Heat deals nonlethal damage to the victim. A character can’t recover from the damage dealt by a hot environment until she gets out of the heat and cools off.
A character in very hot conditions (above 90° F) must attempt a Fortitude saving throw each hour (DC = 15 + 1 per previous check) or take 1d4 nonlethal fire damage. Characters wearing heavy clothing or armor of any sort take a –4 penalty to their saving throws. A character can attempt a Survival check to receive a bonus to this saving throw, and might be able to apply this bonus to other characters as well (see page 148).
In severe heat (above 110° F), a character must attempt a Fortitude saving throw once every 10 minutes (DC = 15 + 1 per previous check) or take 1d4 nonlethal fire damage. Characters wearing heavy clothing or armor of any sort take a –4 penalty to their saves. A character can attempt a Survival check to receive a bonus to this saving throw and might be able to apply this bonus to other characters as well (see page 148).
Extreme heat (air temperature over 140° F, boiling water, fire, and lava) deals lethal fire damage. Breathing air in extreme heat deals 1d6 fire damage per minute (no saving throw). In addition, a character must attempt a Fortitude saving throw every 5 minutes (DC = 15 + 1 per previous check) or take 1d4 nonlethal fire damage. Hotter environments can deal more damage at the GM’s discretion.
A character who takes any damage from heat exposure suffers from heatstroke (same as the fatigued condition; see page 276). These penalties end when the character recovers from the nonlethal damage she took from the heat.
Boiling water deals anywhere from 1d6 to 10d6 fire damage per round of exposure, depending on water temperature and level of immersion.

Catching on Fire

Characters exposed to burning oil, bonfires, and noninstantaneous magical fires might find their clothes, hair, or equipment on fire. Spells or technological items with an instantaneous effect don’t normally set a character on fire, since the heat and flame from these come and go in a flash.
A character at risk of catching fire must succeed at a Reflex saving throw (usually DC 15) or gain the burning condition (see page 273). Those whose clothes or equipment catch fire must attempt a separate Reflex saving throw (at the same DC) for each item. On a failed saving throw, flammable items take the same amount of damage as the character.

Lava Effects

Lava or magma deals a minimum of 2d6 fire damage per round of exposure, while cases of total immersion (such as when a character falls into the crater of an active volcano) deal upward of 20d6 fire damage per round. The exact damage is left to the GM’s discretion, based on situational terrain elements.
Damage from lava continues for 1d3 rounds after exposure ceases, but this additional damage is only half of that dealt during actual contact (that is, 1d6 or 10d6 per round). Immunity or resistance to fire serves as an immunity or resistance to lava or magma. A creature immune or resistant to fire might still drown if completely immersed in lava (see Suffocation and Drowning on page 404).


Radiation is a very real threat to adventurers, whether it’s the radiation emitted from stars or the radiation generated by various technological wonders of the universe. Radiation is a poison effect (see page 414) that weakens an affected creature’s Constitution and can also inflict an affected creature with a disease called radiation sickness. Radiation dangers are organized into four categories: low, medium, high, and severe. The effects of these categories of radiation are described on Table 11–8: Radiation Levels.

Area of Effect

Radiation is an emanation poison, meaning that a victim only needs to enter an area suffused with radiation to be affected by it. Radiation suffuses a spherical area of effect that can extend into solid objects. The closer one gets to the center of an area of radiation, the stronger the radiation effect becomes. Radiation entries list the maximum level of radiation in an area, as well as the radius out to which this radiation level applies. The radiation continues to suffuse each increment out to an equal length beyond that radius, its strength degraded by one level per increment. For example, a spherical area of high radiation with a radius of 20 feet creates a zone of medium radiation spanning 20 feet to 40 feet from the center in all directions, and a similar zone of low radiation spanning 40 to 60 feet from the center.

Curing Radiation Effects

A creature that leaves an area suffused with radiation is essentially cured of the poison effect. Ending the source of radiation or successfully casting remove radioactivity has the same effect. As usual for poison effects, an affected creature requires rest to recover from radiation poisoning. Remove affliction doesn’t cure a creature of the effects of radiation poisoning, but remove radioactivity does.
If a creature has been exposed to enough radiation, it might contract radiation sickness, which acts like a noncontagious disease. Symptoms of radiation sickness include nausea, vomiting, and loss of hair. Radiation sickness can be treated like any disease, although it can’t be cured with remove affliction. Remove radioactivity can cure radiation sickness.


Type poison, emanation (see above); Save Fortitude (see chart)
Track Constitution; Frequency 1/round
Effect At each state of impaired and beyond, the victim must succeed at a DC 18 Fortitude saving throw or contract the radiation sickness disease (see below).
Cure none


Type disease; Save Fortitude (same DC as the level of radiation that caused the radiation sickness)
Track physical; Frequency 1/day
Effect Radiation sickness isn’t contagious.
Cure 3 consecutive saves

Table 11-8: Radiation Levels


Sleep Deprivation

A character who needs to sleep must get at least 6 hours of sleep every night. If she doesn’t, she must attempt a Fortitude save (DC = 15 + 1 per previous check) after each night she doesn’t sleep enough. The first failed check causes her to become fatigued and take a –1 penalty to saving throws against effects that cause the asleep condition (see page 273). A second failed check causes her to become exhausted, and the penalty to saving throws against effects that cause the asleep condition increases to –2.

Smoke Effects

A character who inhales heavy smoke must attempt a Fortitude save each round she’s within the smoke (DC = 15 + 1 per previous check) or spend that round choking and coughing. A character who chokes for 2 consecutive rounds takes 1d6 nonlethal damage. Smoke obscures vision, giving concealment (20% miss chance) to characters within it.

Starvation and Thirst

Characters might find themselves without food or water and with no means to obtain them. In normal climates, Medium characters need at least a gallon of fluids per day to avoid thirst and about a pound of decent food per day to avoid starvation; Small characters need half as much. In very hot climates, characters need two or three times as much water to avoid thirst.
A character can go without water for 1 day plus a number of hours equal to his Constitution score. After this time, the character must succeed at a Constitution check each hour (DC = 10 + 1 per previous check) or take 1d6 nonlethal damage.
A character can go without eating food for 3 days. After this time, the character must succeed at a Constitution check (DC = 10 + 1 per previous check) each day or take 1d6 nonlethal damage.
A character who has taken any damage from lack of food or water is fatigued. Damage from thirst or starvation cannot be recovered until the character gets food or water, as needed—not even magic that restores Hit Points heals this damage.

Suffocation and Drowning

A character who has no air to breathe can hold her breath for a number of rounds equal to twice her Constitution score. If a character takes a standard or full action, the remaining duration that the character can hold her breath is reduced by 1 round. After these rounds have elapsed, the character must attempt a Constitution check (DC = 10 + 1 per previous check) each round in order to continue holding her breath.
When the character fails one of these Constitution checks, she begins to suffocate. In the first round, she is reduced to 0 Hit Points and is unconscious and stable. In the following round, she is no longer stable and begins dying (see page 275). In the third round, she suffocates and dies.
An unconscious character must begin attempting Constitution checks immediately upon losing air supply (or upon becoming unconscious, if the character was conscious when her air was cut off). Once she fails one of these checks, she immediately drops to 0 Hit Points and is dying (see page 275). On the following round, she suffocates and dies.

Slow Suffocation

A Medium creature can breathe easily for 6 hours in a sealed cubic chamber measuring 10 feet on a side. After that time, the creature takes 1d6 nonlethal damage every 15 minutes.
Each additional Medium creature or significant fire source (a torch, for example) proportionally reduces the time the air will last (two Medium creatures will run out of air in 3 hours, and so on). Small characters consume half as much air as Medium characters. A creature stuck in a starship or space station whose life support systems have completely failed will run out of breathable air in a similar fashion; while these structures are often larger than a 10-foot cube, they are also often occupied by several creatures. On average, a crew of four in a Medium starship without a source of fresh air can breathe easily for 20 hours.

Underwater Combat

Land-based creatures usually have considerable difficulty when fighting in water, as it affects a creature’s attack rolls, damage, and movement (see page 137 for more on swimming). The following adjustments apply whenever a character is swimming, walking in chest-deep water, or walking along the bottom of a body of water.

Attacks from Land

Characters swimming or floating in water that is at least chest deep and characters who are fully immersed have cover against attacks made from the surface.

Attacks Underwater

Most attacks made underwater take a –2 penalty and deal half damage. Attacks that deal fire damage do only one-quarter damage. Attacks that deal electricity damage take a –4 penalty rather than a –2 penalty. Melee attacks that deal piercing damage deal full damage. Thrown weapons are ineffective underwater, even when launched from land.

Spellcasting Underwater

A creature that is attempting Constitution checks to hold its breath can’t concentrate enough to cast spells. Some spells might work differently underwater, subject to the GM’s discretion.


Any place where sentient life gathers, lives, and works on a regular basis is referred to as a settlement, and they are just as varied as the types of life-forms that occupy them. Presented on the following pages is a streamlined way to refer to settlements in the Starfinder RPG—stat blocks that quickly list the vital data for a settlement.
For particularly large inhabited places, multiple settlement stat blocks can be used to represent distinct districts or neighborhoods. GMs should feel free to add new qualities to create the settlements they desire.

Settlement Stat Blocks

A settlement stat block usually begins with a brief description, often noting where it is located. A settlement stat block is organized as follows.

Examples of Settlement Governments

The following are just a few of the ways a settlement might be governed.

Examples of Settlement Qualities

The following are just a few of the possible qualities a settlement might have.

Sample Settlements

Two sample settlements that exist within the Pact Worlds are presented below.


Once a bustling space station orbiting Aballon, 01 was built by the native anacites right after the Gap, in order to facilitate trade with life-forms from other worlds. These days, most of Aballon’s major trading ports have districts catering to organic life-forms, as well as localized atmosphere generators, yet 01 might still have remained a vital trading hub had it not been infected with a peculiar virus. The virus, dubbed the Bureaucratic Subroutine, seems tailored to make the machines incredibly inefficient and desirous of elaborate layers of hierarchy and ritual. While traffic to 01 quickly tapered off as a result of a complete quarantine for mechanical organisms, Aballon’s government continues to let the station exist due to the strange discoveries coming out of its labs, and some brave traders from other worlds still come to purchase its advanced tech.


LN space station
Population 26,013 (33% android, 32% human, 35% other)
Government oligarchy
Qualities bureaucratic, technologically advanced
Maximum Item Level 16th


Located at the edge of the southern ice cap of Akiton, this small town was founded to collect water from the melting ice and sell it to the planet’s desert dwellers. Estuar has no law enforcement to speak of, so it also attracts a wide variety of underhanded dealings.


CN trading post
Population 2,340 (48% human, 19% ysoki, 33% other)
Government secret syndicate
Qualities notorious, technologically average
Maximum Item Level 4th

Settlement Technology

Most urban areas are centers of commerce and entertainment bustling with activity. The amenities of city living are usually made possible by technology, whether it’s cutting-edge devices or barely functioning older models. Technology is used in just about everything, from high-end security systems to simple signs and vending machines. Most technology found in settlements can be broken down into the following four categories.


Civil technology includes anything installed by a government to be part of an area’s infrastructure. Streetlights, public transportation, mail-delivery drones, automated street sweepers, and more make up this category of technology. As a great number of people usually rely on the services this kind of technology provides, it is often better protected. The DC to disable or hack into an average piece of civil technology with the Computers or Engineering skill is 23.


Commercial technology is often mass-produced and is used by private citizens and most businesses. This category includes personal communication devices, game consoles, most security cameras and electronic door controls, and much more. The DC to disable or hack into an average piece of commercial technology with the Computers or Engineering skill is 18.


Whether owned by the military or a massive corporation, restricted technology is some of the most advanced and hardest to hack. This category includes private servers, weapon prototypes, high-end security systems and alarms, and much more. The DC to disable or hack into an average piece of restricted technology with the Computers or Engineering skill is 30.


The pervasiveness of technology goes hand in hand with the ability to tweak and alter that technology. Engineers build custom refits for vehicles, and hackers jailbreak personal communication devices to do things the original creators never intended. Custom technology can be any piece of technology described above but with numerous modifications that make hacking or disabling it much trickier. The DC to disable or hack into an average piece of custom technology with the Computers or Survival skill varies, but it might be as high as 40.


The following rules cover the basic features that can be found in structures.


Doors in structures are much more than mere entrances and exits. They can even be encounters all by themselves. Doors come in several types. Consult Table 11–10: Doors for information on common types of doors.

Table 11-10: Doors

Wooden1-1/2 in.5151618
Plastic2 in.8302224
Stone4 in.15602828
Steel2 in.20602828
Airlock door4 in.351604040


Most fabricated structures have some form of lighting built into the ceilings or walls. This lighting provides enough illumination for the inhabitants to see and is often controlled via a simple switch, touch pad, or vocal device. Lighting can usually be turned on and off on a room-to-room basis, though sometimes a structure’s lighting can be deactivated via a central breaker switch (usually located in some kind of control room or service area). A typical manufactured lighting fixture has a break DC of 18, a hardness of 3, and 10 Hit Points (see page 409 for rules on smashing objects).
with darkvision often lack manufactured lighting. Characters without darkvision must provide their own source of lighting to be able to navigate these locations.


Structure walls vary drastically in makeup, ranging from natural, unworked solid stone to reinforced starship bulkheads (though stranger walls exist). While they are typically incredibly difficult to break down or through, they’re generally easy to climb. Table 11–9: Walls contains information on the most common types of walls found in structures.

Concrete3 ft.451554025
Plastic5 in.2587528
Starship bulkhead5 ft.55352,40025
Starship interior3 ft.45301,44020
Steel3 in.30209025
Unworked stone5 ft.651590015
Wooden6 in.2056021

* Per 10-foot-by-10-foot section.


While materials such as glass and wood are commonly found in terrestrial settlements, some substances are bit more unusual. A list of the hardness and Hit Points of often-used substances can be found in Table 11–11: Material Hardness and Hit Points.

Table 11-11: Material Hardness and Hit Points

Cloth, paper, or rope02
Leather or hide35
Transparent aluminum1015
Stone or concrete1515
Iron or steel2030
Adamantine alloy3040
Polycarbon plate4560
Pure adamantine5080

Breaking Objects

When attempting to break an object, you have two choices: smashing it with a weapon or destroying it with sheer strength.

Smashing an Object

Using a weapon to smash a foe’s weapon or an object accessible on the foe’s body is accomplished with the sunder combat maneuver (see page 246). Smashing an unattended object is similar, except this attack roll is opposed by the object’s Armor Class.

Destroying Objects Using Strength

When a character tries to destroy a certain object by using sudden force rather than by dealing damage, he attempts a Strength check (rather than making attack and damage rolls, as with the sunder combat maneuver) to determine whether he succeeds. Since hardness does not affect an object’s break DC, this value depends more on the construction of the item in question than on the material the object is made of. Consult Table 11–13: DCs to Break Objects for a list of common break DCs.
If an object has lost half or more of its Hit Points, the object gains the broken condition (see page 273) and the DC to break it is reduced by 2.
Larger and smaller creatures get bonuses and penalties to Strength checks to break objects as follows: Fine –16, Diminutive –12, Tiny –8, Small –4, Large +4, Huge +8, Gargantuan +12, Colossal +16.

Table 11-12: Size and Armor Class of Objects


Table 11-13: DCs to Break Objects

Break down wooden door16
Burst rope bonds20
Burst steel restraints25
Break down steel door28
Bend nanocarbon bars35