Wilderness, Sanford Robinson Gifford (1823–1880)
Wilderness, Sanford Robinson Gifford (1823–1880)

Outside the safety of city walls, the wilderness is a dangerous place, and many adventurers have gotten lost in its trackless wilds or fallen victim to deadly weather. The following rules give you guidelines on running adventures in a wilderness setting.

Starvation and Thirst

Getting Lost







Falling Trees

Forest Fire









Climatic Zones


Each of the standard terrain types varies by climate. Climate differs from weather, though it affects the weather significantly. Climate describes the generally prevailing atmospheric conditions of a particular region on a planet and usually defines the seasonal temperature extremes. Note that weather and temperature can change dramatically between terrains even within a particular climatic zone – a warm summer evening in a temperate grassland may be a bone-chillingly cold night on a temperate mountain.

The following climatic zones are therefore presented as guidelines, from the poles to the equator:


Transport of Ice (Winter view of the former wine town on the Basil Island in St. Petersburg on the Black River), 1849. Óil on canvas. 68 x 96 cm. Irkutsk Regional Art Museum, Russia Date 1849 Lev Feliksovich Lagorio (1827-1905)
Transport of Ice (Winter view of the former wine town on the Basil Island in St. Petersburg on the Black River), 1849. Óil on canvas. 68 x 96 cm. Irkutsk Regional Art Museum, Russia Date 1849 Lev Feliksovich Lagorio (1827-1905)

The coldest climates surround the poles. These arctic regions are frequently frozen and covered with snow; they have with bitterly cold, dark winters and cool summers. The types of terrain found in arctic climates range from the taiga (the northern or southernmost forests, which extend to the farthest limit trees can grow) to tundra to trackless snowy steppes. The terrain types can be mountainous and glacier-bound, thickly forested, or flat and snow-covered. Despite the harsh conditions, a variety of hardy creatures live in the arctic.


From simple snow fields to ice sheets 2 miles thick that bury entire mountain ranges, the polar regions of a world are both deadly and beautiful in equal parts, its apparent emptiness a facade that hides a complex ecology.

There are three primary geographic divisions of the arctic climatic zone, based on their proximity to the pole: the Boreal Expanse, the Outer Rim, and the High Ice.

The Boreal Expanse: The area within 5 degrees of latitude (approximately 350 miles) of the pole itself.

The Outer Rim: The area within 5 degrees of latitude of the arctic circle.

The High Ice: The remaining areas covered by the polar ice cap.


Temperatures in polar regions usually err on the side of being extreme ‘almost never rising above the level of ‘cold,’ and even then usually only in coastal areas.

Canny travelers know to arm themselves with both mundane and magical forms of protection to safeguard against the worst climate effects of the polar regions. Cold-weather outfits, furs, and spells like endure elements are vital for voyagers hoping to make their way through the arctic while avoiding the cold’s ill effects. Travelers who are part of a caravan equipped with cold-weather gear have all the necessary supplies to make the journey, and can safely endure most challenges presented by cold conditions. Only when a character strays from the caravan does she need to make saving throws against the effects of cold or exposure.


Creatures that suffer nonlethal damage from the cold climate become frostbitten or hypothermic, and are fatigued until the nonlethal damage is removed. It is possible for a character to undergo both frostbite and hypothermia simultaneously by failing two or more saves against cold or exposure, at which point she is treated as though suffering multiple fatigue effects, becoming exhausted.


The base temperature in the polar regions is in the cold range, and only during summertime in the Outer Rim is there any substantial increase in temperature. Most temperature change is governed by sunlight (or its lack), wind, and altitude. The entire High Ice region sits atop a frozen massif over a mile tall, often hiding subglacial mountain ranges. Its elevation alone plunges the average temperature into the range of severe cold, and during the perpetual dark of the winter or during bouts of severe weather, it can become colder still. Assuming the baseline temperature is cold (below 40° F), the following effects may increase the severity of the cold weather to either severe cold (below 0° F) or extreme cold (below -20° F).

Temperature  Variation
Severity Modifier Condition
-1 step Heat  wave 1
+1 step Cold snap 1
+1 step Strong (or stronger) wind 1
+1 step Nightfall
+1 step Low peak or high pass altitude (5,000-15,000 feet) 2
+2 steps High peak altitude (15,000+ feet) 2
1 See Table: Random Weather and Table: Wind Effects.
2 See Altitude Zones.


The extreme latitude of polar regions causes a distortion in the normal pattern of sunrise and sunset experienced in more temperate climes. Near the pole itself, a single day may seem to last all year, with a slow and gradual ascent of the sun for months at a time, though it never rises very high in the sky. Eventually, the sun will slowly sink into the horizon as the paltry polar summer fades into a lingering twilight and lengthy winter night.

Near the pole, both day and night cease to have meaning, as many turns of the stars may pass without the sun ever making an appearance, or the sun may block out the stars for hundreds ‘if not thousands’of hours. The darkest time of year is around the winter solstice; likewise, the brightest time of year takes place around the summer solstice. Because a journey into the polar regions may span many months keep track of the passing of seasons to determine the gradual shift from perpetual day to perpetual night or vice versa. The lighting conditions described below are those that prevail in each polar region for a given portion of the year. Weather conditions (such as overcast) and the cycle of the moon may affect the total amount of light shed during any particular season.


Willard Metcalf (1858-1925): The Winter's Festival Date 1913
Willard Metcalf (1858-1925): The Winter’s Festival Date 1913

At the heart of the midnight sun season, the sun remains fully risen and sheds its light all day and night, appearing to move in a circular pattern in the sky rather than rising and setting. This is treated as bright light during both the day and night.


During this time, the sun sinks only to or just below the horizon even in the middle of the night. This is treated as bright light during the day (which is usually about 20 hours long) and normal light during the night.

This is the normal pattern of distinct days and nights, though the length of these periods is as variable as it is in any other part of the world, depending on the season, with bright light during the day and darkness during the night.


Hans Gude (1825-1903) Title: Winter Afternoon
Hans Gude (1825-1903) Title: Winter Afternoon

The sun ascends only to just at or below the horizon during the day, never truly rising; its refracted light faintly illuminates the sky, but brighter stars are visible. This is treated as dim light during the day (which is usually about 4 hours long) and darkness during the night. Polar Night: The sun is far below the horizon during both day and night, and sheds little or no light, even at the southern horizon. Even faint stars are clearly visible. This is treated as darkness during both the day and night.

Table 2: Seasonal Lighting Patterns
Golarion Month Earth Equivalent Outer Rim High Ice Boreal Expanse
Abadius January Polar Twilight Polar Twilight Polar Night
Calistril February Normal Normal Polar Twilight
Pharast March Normal Normal Normal
Gozran April Normal Normal Normal
Desnus May Midnight Sun Midnight Sun Midnight Sun
Sarenith June Midnight Sun Polar Day Polar Day
Erastus July Midnight Sun Midnight Sun Polar Day
Arodus August Normal Normal Midnight Sun
Rova September Normal Normal Normal
Lamashan October Normal Normal Normal
Neth November Polar Twilight Polar Twilight Polar Twilight
Kuthona December Polar Twilight Polar Night Polar Night


Polar regions are distinct in weather patterns because the unique environmental conditions produce a continental wind condition called a polar vortex. Because of this effect, weather fronts and air masses from outside the pole are deflected or diverted away rather than bringing moisture or warmer air into the region. The coastal regions along its western and eastern edges may see very heavy precipitation in the form of snow (and, rarely, rain during the summer), as may the tundra regions along its southern edges on occasion, but the vast sprawling ice cap is essentially a cold desert, receiving only scant precipitation that is always in the form of snow.


To determine weather effects in a polar region, use the Cold Climate column of Table: Random Weather for areas within 100 miles of a coastline or mountain range. A roll of 81-90 (precipitation) has a 30% chance of producing fog, 60% chance of snow, and 10% chance of sleet or hail. Farther inland than this, the climate is much drier. Use the same column, but replace the result of 91-99 (snowstorm) with 91-99 (windstorm).


Severe or stronger winds carry gusts of snow and ice particles, creating whiteout conditions that block vision beyond 5 feet, as per fog. Creatures in a whiteout move at half speed and take a -4 penalty on Dexterity checks and Dexterity-based skill checks as well as on vision-based Perception checks. Creatures native to cold environments or with the cold subtype take only half these check penalties, but still move at half speed. Creatures able to see normally in snowy conditions, such as frost drakes and white dragons, are unaffected by whiteout conditions.


Besides the perils of keeping warm and navigating, there are a handful of natural and supernatural hazards that are unique to this desolate land.


Caspar David Friedrich (1774-1840) Title Monk in the Snow
Caspar David Friedrich (1774-1840) Title Monk in the Snow

The ancient race that built the eerie city at the North Pole left behind strange arcane engines that still produce emanations of weird blue energy as well as a vile black sludge. This sludge oozes below the surface of the Boreal Expanse through subglacial channels, occasionally burbling to the surface in pools of dark slurry. Arctic winds sometimes bear flecks of the viscous substance and deposit it as a residue of black frost on cliff sides and glaciers.

Type poison, contact; Save Fortitude DC 15

Onset 1 minute; Frequency 1/minute for 6 minutes

Initial Effect 2d6 hp damage (half acid, half cold); Secondary Effect 1d2 Constitution damage; Cure 2 consecutive saves


Creatures that take lethal damage from cold weather exposure may contract this debilitating ailment.

Type disease, injury; Save Fortitude DC 16

Onset 1 day; Frequency 1/day

Effect 1d4 Dexterity damage, and any nonlethal damage incurred from being in a cold environment becomes lethal damage (though it can still cause hypothermia); Cure 2 consecutive saves


Exposure to the strange arcane energies of the Nameless Spires taints those that come within 10 feet with their alien emanations and begins converting their vital tissues into liquefied blue energy. If a creature dies from ergia, its body dissolves and it cannot be raised.

Type disease, contact; Save Fortitude DC 20

Onset 1 day; Frequency 1/day

Effect 1d4 Strength damage and 1d4 Constitution damage, target must make a second Fort save or 1 point of the damage is drain instead, and a creature that has suffered ability drain glows blue as if limned with faerie fire; Cure 2 consecutive saves


 Alfred Wierusz-Kowalski (1849-1915) Title: The Wolf
Alfred Wierusz-Kowalski (1849-1915) Title: The Wolf

Creatures exposed to the long night of the pole can become disoriented and even slip into a complete and fearful madness.

Type insanity; Save Will DC 13

Onset 2d6 days

Effect -4 penalty on Will saves and Wisdom-based skill checks; target is shaken while animals are within sight or hearing (see below.)


This form of insanity has its onset after a character is exposed to polar twilight or polar night for the stated number of days. A character afflicted with howl of the north begins to fear even the tamest beasts, fearing for her safety while simultaneously becoming more animalistic and primitive herself. Whenever a character afflicted with howl of the north sees a creature of the animal type or hears a bestial call (such as a wolf’s howling), she becomes shaken. Characters native to polar regions are immune to this affliction.


During any time when the weather creates bright light (such as during seasons affected by the polar day or during daytime of the midnight sun), characters are susceptible to mirages and must make a DC 15 Perception check at the beginning of each week in order to identify a mirage as such. If a character fails this check, he sees the mirage on the horizon as a body of water, tree line, or other geographic landmark, the specific details of which are subject to GM discretion. The character is not magically compelled to visit the location, but may convince his allies to head that way in hopes of reaching it or otherwise act accordingly if the mirage is tempting enough.


Explorers in polar expeditions are well advised to bring specialized equipment in addition to their normal supplies.

Item Cost Weight
Astrolabe 100 gp 6 lbs.
Cleats 5 gp 2 lbs.
Cold-weather outfit 8 gp 7 lbs.
Dog sled 20 gp 300 lbs.
Frostbite ointment 50 gp 1 lb.
Furs 12 gp 5 lbs.
Map maker’s kit 10 gp 2 lbs.
Pack animal, musk ox 24 gp
Shovel 2 gp 8 lbs.
Skates 10 gp 3 lbs.
Skis and poles 15 gp 6 lbs.
Snow goggles 12 gp
Snowshoes 5 gp 4 lbs.

Astrolabe: Anyone who has been taught how to use this mechanical device can use it at night when the stars are showing to determine the date and time. This process takes 1 minute. An astrolabe grants a +2 circumstance bonus on Knowledge (geography) and Survival checks to navigate in the wilderness (and on Profession [sailor] checks to navigate at sea).

Cleats: These footgear spikes improve the wearer’s ability to move across icy surfaces. Each square of icy terrain costs only 1.5 squares of movement rather than 2 (or 3 squares rather than 4, for sloped icy terrain).

Cold-Weather Outfit: This heavy, quilted outfit grants a +5 circumstance bonus on Fortitude saves against exposure to cold weather.

Dog Sled: This conveyance is typically pulled by 1 or more riding dogs; the sled and any cargo are counted against the total carrying capacity of all dogs in the team to determine encumbrance. If the party is using caravan rules, a dog sled has the following statistics: hp 10; Traveler Capacity 1, Cargo Capacity 2; Limit none; Consumption 1.

Frostbite Ointment: One hour after being applied, this alchemical salve cures any creature suffering from frostbite, though any nonlethal damage from cold or exposure remains until the victim recovers. A creature cannot benefit from frostbite ointment more than once in 24 hours.

Furs: These simple furs are worn over armor and other clothing and grant a +2 circumstance bonus on Fortitude saves against exposure to cold weather. This bonus does not stack with any bonuses gained from the Survival skill.

Map Maker’s Kit: This kit gives anyone drawing a map as they travel a +2 circumstance bonus on Survival skill checks to avoid becoming lost.

Breaking a Road oil on canvas, 93 x 175.6 cm National Gallery of Canada (no. 572), purchased in 1913. Date 1894 William Cruikshank (1848-1922)
Breaking a Road oil on canvas, 93 x 175.6 cm National Gallery of Canada (no. 572), purchased in 1913. Date 1894 William Cruikshank (1848-1922)

Pack animal, Musk Ox: These husky, shaggy beasts are sometimes domesticated as pack animals. Their statistics are identical to aurochs, but they are immune to cold weather effects (though not severe cold and extreme cold effects). Domesticated musk oxen have the docile special quality (see horse, and treat their gore attack as a secondary natural weapon. In the polar rim mountains of more eastern regions, yaks are used as pack animals and have identical statistics.

Shovel: This simple tool is useful for digging shelters or through drifts and other snow barriers.

Skates: These honed metal blades are worn on boots to enable swift passage over ice. The wearer may move (but not Climb) at her full speed on level icy surfaces. Her speed is halved when moving up an icy slope, but she may run or charge downhill on gentle or steep snowy slopes at quadruple speed. However, any skill check penalties for traversing rough ice while wearing skates are doubled, and the wearer takes a –4 penalty on combat maneuver checks to bull rush, drag, or trip, and to CMD against these maneuvers. Donning or removing skates takes 1 minute.

Skis and Poles: These polished wooden slats enable the wearer to glide across level snowy surfaces at his full speed. His speed is halved when moving up a snowy slope, but he may run or charge downhill on gentle or steep snowy slopes at quadruple speed. Any skill check penalties for traversing rough snowy terrain while wearing skis are doubled, and the wearer takes a –4 penalty on combat maneuver checks to bull rush, drag, or trip, and to CMD against these maneuvers. Characters cannot Climb while wearing skis. Donning or removing skis takes 1 minute.

Snow Goggles: These goggles, carved from bone with a narrow slit opening and held in place with leather straps, work as smoked goggles. In addition, they provide immunity to polar mirages.

Snowshoes: This wide footgear made of gut or leather webbing laced across wooden frames improves the wearer’s ability to move across snowy surfaces. Snowshoes reduce the penalty for walking through heavy snow by 50%; for example, if moving through snow normally costs you 2 squares of movement per square traveled, snowshoes reduce this cost to 1.5 squares per square traveled.


Scene in the Arctic, oil on canvas painting by William Bradford, c. 1880, De Young Museum Date circa 1880
Scene in the Arctic, oil on canvas painting by William Bradford, c. 1880, De Young Museum Date circa 1880

An iceberg is a gigantic block or mass of ice that has broken off from a glacier or ice shelf. This iceberg then floats in the world’s oceans and moves via wind and ocean currents. Icebergs are famous for their size and their ability to hide it under water. Typically, only one-tenth of an iceberg’s volume is visible above the water’s surface, while most of its mass is below. In general, the total size of the average iceberg is 1d10 × 25 feet above sea level, with another 9d10 × 25 feet below sea level. They are typically 1d12 × 50 feet across. Icebergs can be several miles across and several hundred feet tall, however. These super-sized icebergs often break up into smaller icebergs when they reach warm waters. Despite their size, icebergs move an average speed of 10 miles per day, which equates to a speed of around 5 feet per round.

Iceberg  Terrain
Feature Growler Standard Super
Super Cliff 10% 15% 20%
Crevasse 5% 5%
Slope, gradual 5% 10%
Slope, steep 50% 20% 15%
Pool 40% 55% 50%
Iceberg Terrain describes in general terms how likely it is that a given square has a terrain element in it. It is divided into growlers (less than 100 feet across), standard icebergs (more than 100 feet across, but less than 2000 feet across), and super icebergs (more than 2000 feet across). Icebergs have a special terrain element, the ice wall, which is marked on the border between squares rather than taking up a square itself.

Cliff: Cliffs are similar to Hills Terrain, but are typically 1d10 × 10 feet tall. Cliffs taller than 60 feet take up 20 feet of horizontal space.

Crevasse: A crevasse is an irregular crack in the ice caused by ocean currents, shifting winds, or large air pockets in the ice. An average crevasse is anywhere from 3d10 × 10 feet long and 1d4 × 25 feet deep (sometimes deep enough to reach the water below), and 5d6 feet wide. A character falling into a crevasse drops into the water or onto the ice at the bottom. In addition, the steep, slick sides of the crevasse offer little opportunity to Climb out of the crevasse unaided (Climb skill check, DC 30). Some crevasses are hidden by thin crusts of ice; a character approaching a hidden crevasse is entitled to a Perception skill check, DC 20, to notice the crevasse before stepping into it, although running or charging characters do not get to make this check.

Ice wall: A vertical plane of ice, an ice wall requires a DC 30 Climb check to ascend. A typical ice wall is 1d8 × 10 feet tall on standard icebergs, and 2d10 × 10 feet tall on super icebergs. Ice walls occur on the edges of squares, not in the squares themselves.

Pool: Melting icebergs often accumulate large pools of freshwater in their valleys, flat surfaces, and at the bottom of their crevasses. These pools are shallow, usually no more than five feet deep and 1d6×5 feet in diameter. It costs 2 squares of movement to enter a square with a pool and the DC of Acrobatics skill checks increases by 3. Pools are typically too shallow to swim in.

Slope, gradual and steep: These function as Hills Terrain, except that Acrobatic skill checks have +2 to their difficulty due to slippery ice.

Stealth and Detection on an Iceberg: The maximum distance in iceberg terrain at which a Perception check for detecting the nearby presence of others can succeed is 4d10 × 10 feet. Standing at a high point of the iceberg may provide a better vantage point, however.


The temperate zone consists of two major subgroups: oceanic and continental. The coastal oceanic zones enjoy a largely steady temperature, regulated by the weather patterns across the ocean, whereas the inland continental zones are warmer in the summer and colder in the winter. How much warmer and how much colder depends on the various landmasses and prevailing weather patterns. The temperate zone covers fertile farmland, high mountains, verdant forests, grasslands, swamps, and many more terrain types. Temperate lands are highly desirable and travelers must be on the lookout for more than just monsters—brigands prey on caravans, armies wage war, and the politics of kingdoms and duchies make their own troubles.


Warmer than the temperate zone, the subtropics also vary widely in terrain type, from hot deserts to vast savannas to dense, broadleaf forests. Rainfall patterns vary widely in these regions, from dry to humid, and while the subtropics rarely see snow or frost, they can suffer intense cold snaps. As the climate tends toward moderation, the weather in the subtropics depends on the terrain to a greater extent.


Martin Johnson Heade (1819-1904) Title: Passion Flowers and Hummingbirds Date c. 1870-83
Martin Johnson Heade (1819-1904) Title: Passion Flowers and Hummingbirds Date c. 1870-83

The tropics are the hottest part of a planet; lying along the equator, they come directly under the sun’s glare for the entirety of the year. Rather than winter or summer, the tropics have a dry season and a wet season, based on the movement of the rain belt from south to north and back again. Again, however, terrain makes a difference: lush, verdant jungles enjoy frequent rainfall, enormous mountains can sport snow at high altitudes, and the sands of massive deserts shift back and forth on the winds.

Aquatic Terrain

Howard Pyle (1853-1911) Title: The Mermaid Date 1910
Howard Pyle (1853-1911) Title: The Mermaid Date 1910

Aquatic terrain is the least hospitable to most PCs, because they can’t breathe there. Aquatic terrain doesn’t offer the variety that land terrain does. The ocean floor holds many marvels, including undersea analogues of any of the terrain elements described earlier in this section, but if characters find themselves in the water because they were bull rushed off the deck of a pirate ship, the tall kelp beds hundreds of feet below them don’t matter. Accordingly, these rules simply divide aquatic terrain into two categories: flowing water (such as streams and rivers) and non-flowing water (such as lakes and oceans).

Flowing Water:

William Keith (1838-1911) Title Hetch Hetchy Side Canyon, I Date circa 1908
William Keith (1838-1911) Title Hetch Hetchy Side Canyon, I Date circa 1908

Large, placid rivers move at only a few miles per hour, so they function as still water for most purposes. But some rivers and streams are swifter; anything floating in them moves downstream at a speed of 10 to 40 feet per round. The fastest rapids send swimmers bobbing downstream at 60 to 90 feet per round. Fast rivers are always at least rough water (Swim DC 15), and whitewater rapids are stormy water (Swim DC 20). If a character is in moving water, move her downstream the indicated distance at the end of her turn. A character trying to maintain her position relative to the riverbank can spend some or all of her turn swimming upstream.

Swept Away: Characters swept away by a river moving 60 feet per round or faster must make DC 20 Swim checks every round to avoid going under. If a character gets a check result of 5 or more over the minimum necessary, she arrests her motion by catching a rock, tree limb, or bottom snag—she is no longer being carried along by the flow of the water. Escaping the rapids by reaching the bank requires three DC 20 Swim checks in a row. Characters arrested by a rock, limb, or snag can’t escape under their own power unless they strike out into the water and attempt to swim their way clear. Other characters can rescue them as if they were trapped in quicksand (described in Marsh Terrain).

Non-Flowing Water:

 Ivan Aivazovsky (1817–1900) Blue pencil.svg wikidata:Q181568 s:hy:Հեղինակ:Հովհաննես Այվազովսկի q:hy:Հովհաննես Այվազովսկի Title English: Azure Grotto, Naples
Ivan Aivazovsky  (1817–1900)    
Title: Azure Grotto, Naples

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

Stealth and Detection Underwater: How far you can see underwater depends on the water’s clarity. As a guideline, creatures can see 4d8 × 10 feet if the water is clear, and 1d8 × 10 feet if it’s murky. Moving water is always murky, unless it’s in a particularly large, slow-moving river.

It’s hard to find cover or concealment to hide underwater (except along the sea floor).

invisibility: An invisible creature displaces water and leaves a visible, body-shaped “bubble” where the water was displaced. The creature still has concealment (20% miss chance), but not total concealment (50% miss chance).


Land-based creatures can have considerable difficulty when fighting in water. Water affects a creature’s attack rolls, damage, and movement. In some cases a creature’s opponents might get a bonus on attacks. The effects are summarized on Table: Combat Adjustments Underwater. They apply whenever a character is swimming, walking in chest-deep water, or walking along the bottom of a body of water.

Combat  Adjustments Underwater
Condition Attack/Damage Movement Off  Balance?1
  Slashing or Bludgeoning Piercing
Freedom of movement normal/normal normal/normal normal No
Has a swim speed -2/half normal normal No
Successful Swim check -2/half2 normal quarter or half3 No
Firm footing4 -2/half2 normal half No
None of the above -2/half2 -2/half normal Yes
1 Creatures flailing about in the water (usually because they failed their Swim checks) have a hard time fighting effectively. An off-balance creature loses its Dexterity bonus to Armor Class, and opponents gain a +2 bonus on attacks against it.
2 A creature without freedom of movement effects or a swim speed makes grapple checks underwater at a -2 penalty, but deals damage normally when grappling.
3 A successful Swim check lets a creature move one-quarter its speed as
a move action or one-half its speed as a full-round action.
4 Creatures have firm footing when walking along the bottom, braced against a ship’s hull, or the like. A creature can only walk along the bottom if it wears or carries enough gear to weigh itself down: at least 16 pounds for Medium creatures, twice that for each size category larger than Medium, and half that for each size category smaller than Medium.

Ranged Attacks Underwater: Thrown weapons are ineffective underwater, even when launched from land. Attacks with other ranged weapons take a –2 penalty on attack rolls for every 5 feet of water they pass through, in addition to the normal penalties for range.

Attacks from Land: Characters swimming, floating, or treading water on the surface, or wading in water at least chest deep, have improved cover (+8 bonus to AC, +4 bonus on Reflex saves) from opponents on land. Land-bound opponents who have freedom of movement effects ignore this cover when making melee attacks against targets in the water. A completely submerged creature has total cover against opponents on land unless those opponents have freedom of movement effects. Magical effects are unaffected except for those that require attack rolls (which are treated like any other effects) and fire effects.

Fire: Nonmagical fire (including alchemist’s fire) does not burn underwater. Spells or spell-like effects with the fire descriptor are ineffective underwater unless the caster makes a caster level check (DC 20 + spell level). If the check succeeds, the spell creates a bubble of steam instead of its usual fiery effect, but otherwise the spell works as described. A supernatural fire effect is ineffective underwater unless its description states otherwise. The surface of a body of water blocks line of effect for any fire spell. If the caster has made the caster level check to make the fire spell usable underwater, the surface still blocks the spell’s line of effect.

Spellcasting Underwater: Casting spells while submerged can be difficult for those who cannot breathe underwater. A creature that cannot breathe water must make a concentration check (DC 15 + spell level) to cast a spell underwater (this is in addition to the caster level check to successfully cast a fire spell underwater). Creatures that can breathe water are unaffected and can cast spells normally. Some spells might function differently underwater, subject to GM discretion.

Bog/Marsh/Swamp Terrain

Hunting in the Pontine Marshes, Oil on canvas, 1833 Horace Vernet (1789-1863)
Hunting in the Pontine Marshes, Oil on canvas, 1833 Horace Vernet (1789-1863)

Two categories of marsh exist: relatively dry moors and watery swamps.

Both are often bordered by lakes (described in Aquatic Terrain), which are effectively a third category of terrain found in marshes.

Marsh Category
Moor Swamp
Shallow bog 20% 40%
Deep bog 5% 20%
Light undergrowth 30% 20%
Heavy undergrowth 10% 20%

Bog: If a square is part of a shallow bog, it has deep mud or standing water of about 1 foot in depth. It costs 2 squares of movement to move into a square with a shallow bog, and the DC of Acrobatics checks in such a square increases by 2.

A square that is part of a deep bog has roughly 4 feet of standing water. It costs Medium or larger creatures 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 (+8 bonus to AC, +4 bonus on Reflex saves). Medium or larger creatures can crouch as a move action to gain this improved cover. Creatures with this improved cover take a –10 penalty on attacks against creatures that aren’t underwater.

Deep bog squares are usually clustered together and surrounded by an irregular ring of shallow bog squares.

Both shallow and deep bogs increase the DC of Stealth checks by 2.

Undergrowth: The bushes, rushes, and other tall grasses in marshes function as undergrowth does in a forest. A square that is part of a bog does not also have undergrowth.

Quicksand: Patches of quicksand present a deceptively solid appearance (appearing as undergrowth or open land) that might trap careless characters. A character approaching a patch of quicksand at a normal pace is entitled to a DC 8 Survival check to spot the danger before stepping in, but charging or running characters don’t have a chance to detect a hidden patch before blundering into it. A typical patch of quicksand is 20 feet in diameter; the momentum of a charging or running character carries him 1d2 × 5 feet into the quicksand.

Effects of Quicksand: Characters in quicksand must make a DC 10 Swim check every round to simply tread water in place, or a DC 15 Swim check to move 5 feet in whatever direction is desired. If a trapped character fails this check by 5 or more, he sinks below the surface and begins to drown whenever he can no longer hold his breath (see the Swim skill description in Using Skills).

Characters below the surface of quicksand may swim back to the surface with a successful Swim check (DC 15, +1 per consecutive round of being under the surface).

Rescue: Pulling out a character trapped in quicksand can be difficult. A rescuer needs a branch, spear haft, rope, or similar tool that enables him to reach the victim with one end of it. Then he must make a DC 15 Strength check to successfully pull the victim, and the victim must make a DC 10 Strength check to hold onto the branch, pole, or rope. If both checks succeed, the victim is pulled 5 feet closer to safety. If the victim fails to hold on, he must make a DC 15 Swim check immediately to stay above the surface.

Hedgerows: Common in moors, hedgerows are tangles of stones, soil, and thorny bushes. Narrow hedgerows function as low walls, and it takes 3 squares of movement to cross them. Wide hedgerows are more than 5 feet tall and take up entire squares. They provide total cover, just as a wall does. It takes 4 squares of movement to move through a square with a wide hedgerow; creatures that succeed on a DC 10 Climb check need only 2 squares of movement to move through the square.

Other Marsh Terrain Elements: Some marshes, particularly swamps, have trees just as forests do, usually clustered in small stands. Paths lead across many marshes, winding to avoid bog areas. As in forests, paths allow normal movement and don’t provide the concealment that undergrowth does.

Stealth and Detection in a Marsh: In a marsh, the maximum distance at which a Perception check for detecting the nearby presence of others can succeed is 6d6 × 10 feet. In a swamp, this distance is 2d8 × 10 feet.

Undergrowth and deep bogs provide plentiful concealment, so it’s easy to use Stealth in a marsh.

Desert Terrain

Eugen Bracht: Rast in der Wüste
Eugen Bracht: Rast in der Wüste

Desert terrain exists in warm, temperate, and cold climates, but all deserts share one common trait: little rain. The three categories of desert terrain are tundra (cold desert), rocky deserts (often temperate), and sandy deserts (often warm).

Tundra differs from the other desert categories in two important ways. Because snow and ice cover much of the landscape, it’s easy to find water. During the height of summer, the permafrost thaws to a depth of a foot or so, turning the landscape into a vast field of mud. The muddy tundra affects movement and skill use as the shallow bogs described in Marsh Terrain, although there’s little standing water.

The table below describes terrain elements found in each of the three desert categories. The terrain elements on this table are mutually exclusive; for instance, a square of tundra might contain either light undergrowth or an ice sheet, but not both.

Desert  Category
Tundra Rocky Sandy
Light undergrowth 15% 5% 5%
Ice sheet 25%
Light rubble 5% 30% 10%
Dense rubble 30% 5%
Sand dunes 50%

Light Undergrowth: Consisting of scrubby, hardy bushes and cacti, light undergrowth functions as described for other terrain types.

Ice Sheet: The ground is covered with slippery ice. It costs 2 squares of movement to enter a square covered by an ice sheet, and the DC of Acrobatics checks there increases by 5. A DC 10 Acrobatics check is required to run or charge across an ice sheet.

Light Rubble: Small rocks are strewn across the ground, making nimble movement more difficult. The DC of Acrobatics checks increases by 2.

Dense Rubble: This terrain feature consists of more and larger stones. It costs 2 squares of movement to enter a square with dense rubble. The DC of Acrobatics checks increases by 5, and the DC of Stealth checks increases by 2.

Sand Dunes: Created by the action of wind on sand, dunes function as hills that move. If the wind is strong and consistent, a sand dune can move several hundred feet in a week’s time. Sand dunes can cover hundreds of squares. They always have a gentle slope pointing in the direction of the prevailing wind and a steep slope on the leeward side.

Other Desert Terrain Features: Tundra is sometimes bordered by forests, and the occasional tree isn’t out of place in the cold wastes. Rocky deserts have towers and mesas consisting of flat ground surrounded on all sides by cliffs and steep slopes (as described in Mountain Terrain). Sandy deserts sometimes have quicksand; this functions as described in Marsh Terrain, although desert quicksand is a waterless mixture of fine sand and dust. All desert terrain is crisscrossed with dry streambeds (treat as trenches 5 to 15 feet wide) that fill with water on the rare occasions when rain falls.

Stealth and Detection in the Desert: In general, the maximum distance in desert terrain at which a Perception check for detecting the nearby presence of others can succeed is 6d6 × 20 feet; beyond this distance, elevation changes and heat distortion in warm deserts makes sight-based Perception impossible. The presence of dunes in sandy deserts limits spotting distance to 6d6 × 10 feet. The scarcity of undergrowth or other elements that offer concealment or cover makes using Stealth more difficult.

Common Desert Hazards


A sandstorm reduces visibility to 1d10 × 5 feet and provides a –4 penalty on Perception checks. A sandstorm deals 1d3 points of nonlethal damage per hour to any creatures caught in the open, and leaves a thin coating of sand in its wake. Driving sand creeps in through all but the most secure seals and seams, chafing skin and contaminating carried gear.

Forest Terrain

William Trost Richards (1833-1905) Title Woodland Landscape (Woodland Glade) Date 1860
William Trost Richards (1833-1905) Title Woodland Landscape (Woodland Glade) Date 1860

Forest terrain can be divided into three categories: sparse, medium, and dense.

An immense forest could have all three categories within its borders, with more sparse terrain at the outer edge of the forest and dense forest at its heart.

The table below describes in general terms how likely it is that a given square has a terrain element in it.

Category  of Forest
  Sparse Medium Dense
Typical trees 50% 70% 80%
Massive trees 10% 20%
Light undergrowth 50% 70% 50%
Heavy undergrowth 20% 50%


The most important terrain element in a forest is the trees, obviously. A creature standing in the same square as a tree gains partial cover, which grants a +2 bonus to Armor Class and a +1 bonus on Reflex saves. The presence of a tree doesn’t otherwise affect a creature’s fighting space, because it’s assumed that the creature is using the tree to its advantage when it can. The trunk of a typical tree has AC 4, hardness 5, and 150 hp. A DC 15 Climb check is sufficient to Climb a tree. Medium and dense forests have massive trees as well. These trees take up an entire square and provide cover to anyone behind them. They have AC 3, hardness 5, and 600 hp. Like their smaller counterparts, it takes a DC 15 Climb check to Climb them.

Undergrowth Vines, roots, and short bushes cover much of the ground in a forest. A space covered with light undergrowth costs 2 squares of movement to move into, and provides concealment. Undergrowth increases the DC of Acrobatics and Stealth checks by 2 because the leaves and branches get in the way. Heavy undergrowth costs 4 squares of movement to move into and provides concealment with a 30% miss chance (instead of the usual 20%). It increases the DC of Acrobatics checks by 5. Heavy undergrowth is easy to hide in, granting a +5 circumstance bonus on Stealth checks. Running and charging are impossible. 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.

Forest Canopy It’s common for elves and other forest dwellers to live on raised platforms far above the surface floor. These wooden platforms often have rope bridges between them. To get to the treehouses, characters ascend the trees’ branches (Climb DC 15), use rope ladders (Climb DC 0), or take pulley elevators (which can be made to rise a number of feet equal to a Strength check, made each round as a full-round action). Creatures on platforms or branches in a forest canopy are considered to have cover when fighting creatures on the ground, and in medium or dense forests they have concealment as well.

Other Forest Terrain Elements Fallen logs generally stand about 3 feet high and provide cover just as low walls do. They cost 5 feet of movement to cross. Forest streams average 5 to 10 feet wide and no more than 5 feet deep. Pathways wind through most forests, allowing normal movement and providing neither cover nor concealment. These paths are less common in dense forests, but even unexplored forests have occasional game trails.

Stealth and Detection in a Forest

In a sparse forest, the maximum distance at which a Perception check for detecting the nearby presence of others can succeed 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 in the forest. Logs and massive trees provide cover, which also makes hiding possible.

The background noise in the forest makes Perception checks that rely on sound more difficult, increasing the DC of the check by 2 per 10 feet, not 1.
Common Hazards Within Forest Terrain


Most campfire sparks ignite nothing, but if conditions are dry, winds are strong, or the forest floor is dried out and flammable, a forest fire can result. Lightning strikes often set trees ablaze and start forest fires in this way. Whatever the cause of the fire, travelers can get caught in the conflagration.

A forest fire can be spotted from as far away as 2d6 × 100 feet by a character who makes a Perception check, treating the fire as a Colossal creature (reducing the DC by 16). If all characters fail their Perception checks, the fire moves closer to them. They automatically see it when it closes to half the original distance. With proper elevation, the smoke from a forest fire can be spotted as far as 10 miles away.

Characters who are blinded or otherwise unable to make Perception checks can feel the heat of the fire (and thus automatically “spot” it) when it is 100 feet away.

The leading edge of a fire (the downwind side) can advance faster than a human can run (assume 120 feet per round for winds of moderate strength). Once a particular portion of the forest is ablaze, it remains so for 2d4 × 10 minutes before dying to a smoking wasteland. Characters overtaken by a forest fire might find the leading edge of the fire advancing away from them faster than they can keep up, trapping them deeper and deeper within its grasp.

Within the bounds of a forest fire, a character faces three dangers: heat damage, catching on fire, and smoke inhalation.

Heat Damage Getting caught within a forest fire is even worse than being exposed to extreme heat (see Heat Dangers). Breathing the air causes a character to take 1d6 points of fire damage per round (no save). In addition, a character must make a Fortitude save every 5 rounds (DC 15, +1 per previous check) or take 1d4 points of nonlethal damage. A character who holds his breath can avoid the lethal damage, but not the nonlethal damage. Those wearing heavy clothing or any sort of armor take a –4 penalty on their saving throws. Those wearing metal armor or who come into contact with very hot metal are affected as if by a heat metal spell.

Catching on Fire Characters engulfed in a forest fire are at risk of catching on fire when the leading edge of the fire overtakes them, and continue to be at risk once per minute thereafter.

Smoke Inhalation Forest fires naturally produce a great deal of smoke. A character who breathes heavy smoke must make a Fortitude save each round (DC 15, +1 per previous check) or spend that round choking and coughing. A character who chokes for 2 consecutive rounds takes 1d6 points of nonlethal damage. Smoke also provides concealment to characters within it.

Jungle Storms

Source: Jungle storm information from Pathfinder Chronicles: Heart of the Jungle
Artist Martin Johnson Heade (1819–1904) Blue pencil.svg wikidata:Q3123472 Martin Johnson Heade: Cattleya Orchid and Three Hummingbirds Object type painting Description English: Cattleya Orchid and Three Brazilian Hummingbirds Date 1871
Artist Martin Johnson Heade  (1819–1904)  : Cattleya Orchid and Three Brazilian Hummingbirds Date 1871

Equatorial storms can be both devastating and predictable. In many jungle areas, rainstorms come every afternoon and last anywhere from 20 minutes to 6 hours. In other areas, ferocious storms break suddenly and end quickly. These tend to deliver more precipitation than heavy wind, as the thick jungle growth protects those beneath it from the direct force of the storm. Still, in addition to the inconvenience of being wet and miserable, jungle storms bring with them the following dangerous possibilities.

Falling Trees Native flora, especially the tall trees which form the jungle’s canopy, have generally adapted to seasonal storms and rarely come down due to rainfall. At times, though, a particularly strong storm can erode the soil and pound a tree with enough force to cause it to topple, possibly setting off a chain reaction. Anyone in the path of a falling tree must make a DC 14 Reflex save to leap clear or take 3d6 points of damage. Fallen trees can block routes, but travelers can usually Climb over the trees, which measure anywhere from 5 to 20 feet in diameter. Fallen trees can, however, block river travel and require travelers to abandon their boats or to drag them out of the river and portage them around the obstruction.

Lightning Strikes Lightning strikes also occur during jungle storms, though they tend to be less frequent than in temperate thunderstorms. It is exceedingly rare for a creature to be struck by lightning, though such an unlucky character would suffer between 4d8 and 10d8 points of electricity damage from the strike. Due to the humid nature of the jungle, lightning strikes rarely produce forest fires, yet out on the plains it’s possible for a strike to ignite a drought-plagued field and start a wildfire.

Poisonous Foods One of the more common and effective defenses against predation in the jungle is simply being dangerous to eat. From an innocuous leaf to a brightly colored frog to the poison weeping injection vine, it seems everything in the jungle can cause chemical harm to the unwary. If a player is brave or naive enough to eat a jungle plant or animal she’s unfamiliar with or is maneuvered into doing so by well-meaning or mischievous locals you may want to roll on the following table to determine whether or not the item is poisonous. The effects listed below may either represent actual poison or simply compounds travelers have not properly adapted to.

Quicksand CR 3 Quicksand is nothing more than sand or loose soil that is supersaturated with water. This effect allows creatures to sink into the mixture much as if they’re settling into nothing more than silty water, but then requires them to fight the crushing weight of sand as if they had been buried alive to escape. The main dangers of quicksand are becoming trapped and unable to move or having one’s head submerged and suffocating. Even a trapped individual who manages to stay partway out of the quicksand is still at risk from the dangers of exposure and is easy pickings for the other denizens of the jungle.

Tainted Water Tainted water poses an attractive danger to a thirsty traveler. A character can make a DC 10 Survival check to tell fresh water from tainted water. Most jungle trackers know that still water holds the greatest potential for contamination, while fast-moving streams and headwaters are more likely to be fresh. A purify food and drink spell, of course, removes all doubt, and create water renders the question moot. Canny adventurers pack clean bowls or canteens with which to carry magically purified or created water and boil any water they’re forced to harvest from lakes or rivers (effectively eliminating the threat of disease). Tainted water can have any number of causes, from dangerous local plants leaching poison into the water, to a battleground or dung heap upstream, or even a simple animal corpse decaying and putrefying at the water’s edge. If a character drinks tainted water, she must make a DC 12 Fortitude save or contract Filth fever. The amount of water ingested does not modify the save or the severity of the disease in any way, as a thimbleful of tainted water can have the same effect as a bucketful. Wading through tainted water can also communicate Filth fever, as tiny drops of the water get on the character’s hands, clothes, and face and can later be transferred to the mouth, nose, or eyes as the character moves about. It is more difficult to contract a disease in this way, though. When wading or swimming through tainted water, a character receives a +2 circumstance bonus on her save to resist contracting Filth fever.

Leeches Leeches are prevalent in the jungle and are most commonly found in slow-moving rivers or stagnant ponds, though they can also live in deep or fast-moving water. Stagnant water in the jungle has a 50% chance of containing leeches, slow moving water a 25% chance, and swifter rivers a 10% chance. Ordinary leeches are disgusting but mostly harmless. They may attach themselves to characters moving through the water, but most leeches prefer to feed on carrion, plant matter, and other leeches. Still, it’s disturbing for even the most seasoned adventurer to emerge from a river and find sticky blobs of leech plastered to her skin, and though leeches themselves are not poisonous, they are capable of spreading blood-borne diseases from one victim to the next as they vomit the contents of their stomachs into the wound. Thus, you may wish to assign a percentile chance of contracting one of the following injury diseases: Bonecrusher (Dengue) Fever, Brainworms, Dysentery, Firegut, Greenscale, Malaria (Jungle Fever), Pulsing Puffs, Sleeping Sickness (save DC varies by disease).

Ghost Leech CR 1/2 Unfortunately, the standard leech is not alone in the rivers of the Mwangi Expanse. Both giant leeches and nauseating leech swarms make their homes here, and they are seldom content with a sip of the victim’s blood, preferring instead to drain her dry. In addition, Mwangi streams are also home to the translucent terror known as the ghost leech. A ghost leech is a 6-inch-long leech with almost completely clear skin, appearing as little more than a ripple in the water as it moves. A gentle attacker with an anesthetizing poison, it can often attach itself to a humanoid or other prey animal without being noticed (Stealth +20). Once attached, the ghost leech quietly drains its host of blood, inflicting 1 point of Constitution damage each round that it’s attached. As it fills with blood, it gradually becomes more and more visible, taking a cumulative -5 penalty on Stealth checks and allowing a new Perception check to notice it for each point of Constitution it drains. The ghost leech detaches itself once it has dealt at least 3 points of Constitution damage and slithers back into the water. Ghost leeches have no other combat abilities and negligible hit points and AC; an adventurer can kill one easily by tearing it off and squishing it, assuming she notices it before it drops away and leaves her weakened and pale. As such, it works better as a natural hazard of CR 1/2 than as an actual combat encounter.

Flash Floods (CR 3) Heavy rains can cause rivers to swell and break free of their banks, turning valleys to rushing mudflows and filthy lakes. Experienced guides know to stay clear of rivers during rainstorms, but tropical storms often erupt quickly, and the torrential downpour can catch adventurers in a flash flood without warning. At other times, a storm some distance away can push swelling water down the river and catch travelers in a rushing wall of water.

A traveler can make a DC 20 Survival check to notice the telltale rise in water or other dangerous conditions that signal an impending flash flood. Success means the traveler and her allies have 1d4 rounds to prepare or reach high ground before the flood strikes. A flash flood sweeps past at a speed of 60 feet with enough force to knock down trees and toss boulders around (see fast-flowing water.) At the GM’s discretion, characters caught in a flash flood might suffer additional effects, outlined below.

Characters within 50 feet of a flash flood must make a DC 12 Reflex save or take 2d6 points of damage from hurtling debris. Any character wading through a river or within 10 feet of the river’s edge is caught in the flash flood when it erupts and is subjected to a bull rush (CMB +20). A successful bull rush indicates the character is swept away, taking 2d6 points of damage per round (a DC 12 Reflex save each round negates this damage). Swim checks are possible in a flash flood, but they are difficult due to the churning, raging waters and should be treated as stormy water (Pathfinder RPG Core Rulebook 108), with DC 20 Swim checks required to move through the torrent. Most flash floods last 3d6 minutes before subsiding, but on occasion longer flash floods may occur. It’s also important to note that certain animals may sense an impending flood before adventurers, and even if the player characters manage to reach the safety of high ground, they find themselves face to face with other jungle denizens who aren’t interested in sharing it.


Wojciech Gerson (1831-1901) Title: Rock rubble in the White Water Valley in the Tatras.
Wojciech Gerson (1831-1901) Title: Rock rubble in the White Water Valley in the Tatras.

A hill can exist in most other types of terrain, but hills can also dominate the landscape. Hills terrain is divided into two categories: gentle hills and rugged hills.

Hills terrain often serves as a transition zone between rugged terrain such as mountains and flat terrain such as plains.

Hills Category
Gentle Hills Rugged Hills
Gradual slope 75% 40%
Steep slope 20% 50%
Cliff 5% 10%
Light undergrowth 15% 15%


Gradual Slope: This incline isn’t steep enough to affect movement, but characters gain a +1 bonus on melee attacks against foes downhill from them.

Lev Lagorio (1827–1905) Title: A Caucasian Gorge, Date - 1893
Lev Lagorio (1827–1905) Title: A Caucasian Gorge, Date – 1893

Steep Slope: Characters moving uphill (to an adjacent square of higher elevation) must spend 2 squares of movement to enter each square of steep slope. Characters running or charging downhill (moving to an adjacent square of lower elevation) must succeed on a DC 10 Acrobatics check upon entering the first steep slope square. Mounted characters make a DC 10 Ride check instead. Characters who fail this check stumble and must end their movement 1d2 × 5 feet later. Characters who fail by 5 or more fall prone in the square where they end their movement. A steep slope increases the DC of Acrobatics checks by 2.

Cliff: A cliff typically requires a DC 15 Climb check to scale and is 1d4 × 10 feet tall, although the needs of your map might mandate a taller cliff. A cliff isn’t perfectly vertical, taking up 5-foot squares if it’s less than 30 feet tall and 10-foot squares if it’s 30 feet or taller.

Light Undergrowth: Sagebrush and other scrubby bushes grow on hills, although they rarely cover the landscape. Light undergrowth provides concealment and increases the DC of Acrobatics and Stealth checks by 2.

Other Hills Terrain Elements: Trees aren’t out of place in hills terrain, and valleys often have active streams (5 to 10 feet wide and no more than 5 feet deep) or dry streambeds (treat as a trench 5 to 10 feet across) in them. If you add a stream or streambed, remember that water always flows downhill.

Stealth and Detection in Hills: In gentle hills, the maximum distance at which a Perception check for detecting the nearby presence of others can succeed is 2d10 × 10 feet. In rugged hills, this distance is 2d6 × 10 feet.

Hiding in hills terrain can be difficult if there isn’t undergrowth around. A hilltop or ridge provides enough cover to hide from anyone below the hilltop or ridge.

Mountains Terrain

Edward Theodore Compton (1849-1921) Matterhorn Date 1879
Edward Theodore Compton (1849-1921) Matterhorn Date 1879

The three mountain terrain categories are alpine meadows, rugged mountains, and forbidding mountains.

As characters ascend into a mountainous area, they’re likely to face each terrain category in turn, beginning with alpine meadows, extending through rugged mountains, and reaching forbidding mountains near the summit.

Mountains have an important terrain element, the rock wall, that is marked on the border between squares rather than taking up squares itself.

Mountain  Category
Alpine Meadow Rugged Forbidding
Gradual slope 50% 25% 15%
Steep slope 40% 55% 55%
Cliff 10% 15% 20%
Chasm 5% 10%
Light undergrowth 20% 10%
Scree 20% 30%
Dense rubble 20% 30%


Gradual and Steep Slopes: These function as described in Hills Terrain.

Cliff: These terrain elements also function like their hills terrain counterparts, but they’re typically 2d6 × 10 feet tall. Cliffs taller than 80 feet take up 20 feet of horizontal space.

Chasm: Usually formed by natural geological processes, chasms function like pits in a dungeon setting. Chasms aren’t hidden, so characters won’t fall into them by accident (although bull rushes are another story). A typical chasm is 2d4 × 10 feet deep, at least 20 feet long, and anywhere from 5 feet to 20 feet wide. It takes a DC 15 Climb check to Climb out of a chasm. In forbidding mountain terrain, chasms are typically 2d8 × 10 feet deep.

Light Undergrowth: This functions as described in Forest Terrain.

Scree: A field of shifting gravel, scree doesn’t affect speed, but it can be treacherous on a slope. The DC of Acrobatics checks increases by 2 if there’s scree on a gradual slope and by 5 if there’s scree on a steep slope. The DC of Stealth checks increases by 2 if the scree is on a slope of any kind.

Dense Rubble: The ground is covered with rocks of all sizes. It costs 2 squares of movement to enter a square with dense rubble. The DC of Acrobatics checks on dense rubble increases by 5, and the DC of Stealth checks increases by 2.

Rock Wall: A vertical plane of stone, rock walls require DC 25 Climb checks to ascend. A typical rock wall is 2d4 × 10 feet tall in rugged mountains and 2d8 × 10 feet tall in forbidding mountains. Rock walls are drawn on the edges of squares, not in the squares themselves.

Cave Entrance: Found in cliff and steep slope squares and next to rock walls, cave entrances are typically between 5 and 20 feet wide and 5 feet deep. A cave could be anything from a simple chamber to the entrance to an elaborate dungeon. Caves used as monster lairs typically have 1d3 rooms that are 1d4 × 10 feet across.

Other Mountain Terrain Features: Most alpine meadows begin above the treeline, so trees and other forest elements are rare in the mountains. Mountain terrain can include active streams (5 to 10 feet wide and no more than 5 feet deep) and dry streambeds (treat as a trench 5 to 10 feet across). Particularly high-altitude areas tend to be colder than the lowland areas that surround them, so they might be covered in ice sheets (described in Desert Terrain).

Stealth and Detection in Mountains: As a guideline, the maximum distance in mountain terrain at which a Perception check for detecting the nearby presence of others can succeed is 4d10 × 10 feet. Certain peaks and ridgelines afford much better vantage points, of course, and twisting valleys and canyons have much shorter spotting distances. Because there’s little vegetation to obstruct line of sight, the specifics on your map are your best guide for the range at which an encounter could begin. As in hills terrain, a ridge or peak provides enough cover to hide from anyone below the high point.

It’s easier to hear faraway sounds in the mountains. The DC of Perception checks that rely on sound increase by 1 per 20 feet between listener and source, not per 10 feet.

Common Mountain Hazards

Avalanches (CR 7)

The combination of high peaks and heavy snowfalls means that avalanches are a deadly peril in many mountainous areas. While avalanches of snow and ice are common, it’s also possible to have an avalanche of rock and soil.

An avalanche can be spotted from as far away as 1d10 × 500 feet by a character who makes a DC 20 Perception check, treating the avalanche as a Colossal creature. If all characters fail their Perception checks to determine the encounter distance, the avalanche moves closer to them, and they automatically become aware of it when it closes to half the original distance. It’s possible to hear an avalanche coming even if you can’t see it. Under optimum conditions (no other loud noises occurring), a character who makes a DC 15 Perception check can hear the avalanche or landslide when it is 1d6 × 500 feet away. This check might have a DC of 20, 25, or higher in conditions where hearing is difficult (such as in the middle of a thunderstorm).

A landslide or avalanche consists of two distinct areas: the bury zone (in the direct path of the falling debris) and the slide zone (the area the debris spreads out to encompass). Characters in the bury zone always take damage from the avalanche; characters in the slide zone might be able to get out of the way. Characters in the bury zone take 8d6 points of damage, or half that amount if they make a DC 15 Reflex save. They are subsequently buried. Characters in the slide zone take 3d6 points of damage, or no damage if they make a DC 15 Reflex save. Those who fail their saves are buried.

Buried characters take 1d6 points of nonlethal damage per minute. If a buried character falls unconscious, he must make a DC 15 Constitution check or take 1d6 points of lethal damage each minute thereafter until freed or dead.

The typical avalanche has a width of 1d6 × 100 feet, from one edge of the slide zone to the opposite edge. The bury zone in the center of the avalanche is half as wide as the avalanche’s full width.

To determine the precise location of characters in the path of an avalanche, roll 1d6 × 20; the result is the number of feet from the center of the path taken by the bury zone to the center of the party’s location. Avalanches of snow and ice advance at a speed of 500 feet per round, while rock and soil avalanches travel at a speed of 250 feet per round.


Lev Lagorio (1827–1905) Title- In the mountains of the Caucasus, Date 1879
Lev Lagorio (1827–1905) Title- In the mountains of the Caucasus, Date 1879

High altitude travel can be extremely fatiguing ‘and sometimes deadly’ to creatures that aren’t used to it. Cold becomes extreme, and the lack of oxygen in the air can wear down even the most hardy of warriors.

Acclimated Characters: Creatures accustomed to high altitude generally fare better than lowlanders. Any creature with an Environment entry that includes mountains is considered native to the area and acclimated to the high altitude. Characters can also acclimate themselves by living at high altitude for a month. Characters who spend more than two months away from the mountains must reacclimate themselves when they return. undead, constructs, and other creatures that do not breathe are immune to altitude effects.

Altitude Zones: In general, mountains present three possible altitude bands: low pass, low peak/high pass, and high peak.

Low Pass (lower than 5,000 feet): Most travel in low mountains takes place in low passes, a zone consisting largely of alpine meadows and forests. Travelers might find the going difficult (which is reflected in the movement modifiers for traveling through mountains), but the altitude itself has no game effect.

Low Peak or High Pass (5,000 to 15,000 feet): Ascending to the highest slopes of low mountains, or most normal travel through high mountains, falls into this category. All non-acclimated creatures labor to breathe in the thin air at this altitude. Characters must succeed on a Fortitude save each hour (DC 15, +1 per previous check) or be fatigued. The fatigue ends when the character descends to an altitude with more air. Acclimated characters do not have to attempt the Fortitude save.

High Peak (more than 15,000 feet): The highest mountains exceed 15,000 feet in height. At these elevations, creatures are subject to both high altitude fatigue (as described above) and altitude sickness, whether or not they’re acclimated to high altitudes. Altitude sickness represents long-term oxygen deprivation, and affects mental and physical ability scores. After each 6-hour period a character spends at an altitude of over 15,000 feet, he must succeed on a Fortitude save (DC 15, +1 per previous check) or take 1 point of damage to all ability scores. Creatures acclimated to high altitude receive a +4 competence bonus on their saving throws to resist high altitude effects and altitude sickness, but eventually even seasoned mountaineers must abandon these dangerous elevations.


William W. Gosling (1824-1883): A Hot Day in the Harvest Field
William W. Gosling (1824-1883): A Hot Day in the Harvest Field

Plains come in three categories: farms, grasslands, and battlefields. Farms are common in settled areas, while grasslands represent untamed plains. The battlefields where large armies clash are temporary places, usually reclaimed by natural vegetation or the farmer’s plow. Battlefields represent a third terrain category because adventurers tend to spend a lot of time there, not because they’re particularly prevalent.

The table below shows the proportions of terrain elements in the different categories of plains. On a farm, light undergrowth represents most mature grain crops, so farms growing vegetable crops will have less light undergrowth, as will all farms during the time between harvest and a few months after planting.

The terrain elements in the table below are mutually exclusive.

  Plains Category
Farm Grassland Battlefield
Light undergrowth 40% 20% 10%
Heavy undergrowth 10%
Light rubble 10%
Trench 5% 5%
Berm 5%

Undergrowth: Whether they’re crops or natural vegetation, the tall grasses of the plains function like light undergrowth in a forest. Particularly thick bushes form patches of heavy undergrowth that dot the landscape in grasslands.

Light Rubble: On the battlefield, light rubble usually represents something that was destroyed: the ruins of a building or the scattered remnants of a stone wall, for example. It functions as described in the Desert Terrain section.

Trench: Often dug before a battle to protect soldiers, a trench functions as a low wall, except that it provides no cover against adjacent foes. It costs 2 squares of movement to leave a trench, but it costs nothing extra to enter one. Creatures outside a trench who make a melee attack against a creature inside the trench gain a +1 bonus on melee attacks because they have higher ground. In farm terrain, trenches are generally irrigation ditches.

Berm: A common defensive structure, a berm is a low, earthen wall that slows movement and provides a measure of cover. Put a berm on the map by drawing two adjacent rows of steep slope (described in Hills Terrain), with the edges of the berm on the downhill side. Thus, a character crossing a 2-square berm will travel uphill for 1 square, then downhill for 1 square. Two square berms provide cover as low walls for anyone standing behind them. Larger berms provide the low wall benefit for anyone standing 1 square downhill from the top of the berm.

Fences: Wooden fences are generally used to contain livestock or impede oncoming soldiers. It costs an extra square of movement to cross a wooden fence. A stone fence provides a measure of cover as well, functioning as low walls. Mounted characters can cross a fence without slowing their movement if they succeed on a DC 15 Ride check. If the check fails, the steed crosses the fence, but the rider falls out of the saddle.

Other Plains Terrain Features: Occasional trees dot the landscape in many plains, although on battlefields they’re often felled to provide raw material for siege engines (described in Urban Features). Hedgerows (described in Marsh Terrain) are found in plains as well. Streams, generally 5 to 20 feet wide and 5 to 10 feet deep, are commonplace.

Stealth and Detection in Plains: In plains terrain, the maximum distance at which a Perception check for detecting the nearby presence of others can succeed is 6d6 × 40 feet, although the specifics of your map might restrict line of sight. Cover and concealment are not uncommon, so a good place of refuge is often nearby, if not right at hand.

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