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WILDERNESS, WEATHER, & ENVIRONMENT

WILDERNESS

GETTING LOST
There are many ways to get lost in the wilderness. Following an obvious road, trail, or feature such as a stream or shoreline prevents any possibility of becoming lost, but travelers striking off cross-country may become disoriented—especially in conditions of poor visibility or in difficult terrain.
Poor Visibility: Any time characters cannot see at least 60 feet in the prevailing conditions of visibility, they may become lost. Characters traveling through fog, snow, or a downpour might easily lose the ability to see any landmarks not in their immediate vicinity. Similarly, characters traveling at night may be at risk, too, depending on the quality of their light sources, the amount of moonlight, and whether they have darkvision or lowlight vision.
Difficult Terrain: Any character in forest, moor, hill, or mountain terrain may become lost if he or she moves away from a trail, road, stream, or other obvious path or track. Forests are especially dangerous because they obscure far-off landmarks and make it hard to see the sun or stars.
Chance to Get Lost: If conditions exist that make getting lost a possibility, the character leading the way must succeed on a Survival check or become lost. The difficulty of this check varies based on the terrain, the visibility conditions, and whether or not the character has a map of the area being traveled through. Refer to the table below and use the highest DC that applies.

A character with at least 5 ranks in Knowledge (geography) or Knowledge (local) pertaining to the area being traveled through gains a +2 bonus on this check.
Check once per hour (or portion of an hour) spent in local or overland movement to see if travelers have become lost. In the case of a party moving together, only the character leading the way makes the check.
Effects of Being Lost: If a party becomes lost, it is no longer certain of moving in the direction it intended to travel. Randomly determine the direction in which the party actually travels during each hour of local or overland movement. The characters’ movement continues to be random until they blunder into a landmark they can’t miss, or until they recognize that they are lost and make an effort to regain their bearings.
Recognizing that You’re Lost: Once per hour of random travel, each character in the party may attempt a Survival check (DC 20, –1 per hour of random travel) to recognize that they are no longer certain of their direction of travel. Some circumstances may make it obvious that the characters are lost.
Setting a New Course: A lost party is also uncertain of determining in which direction it should travel in order to reach a desired objective. Determining the correct direction of travel once a party has become lost requires a Survival check (DC 15, +2 per hour of random travel). If a character fails this check, he chooses a random direction as the “correct” direction for resuming travel.
Once the characters are traveling along their new course, correct or incorrect, they may get lost again. If the conditions still make it possible for travelers to become lost, check once per hour of travel as described in Chance to Get Lost, above, to see if the party maintains its new course or begins to move at random again.
Conflicting Directions: It’s possible that several characters may attempt to determine the right direction to proceed after becoming lost. Make a Survival check for each character in secret, then tell the players whose characters succeeded the correct direction in which to travel, and tell the players whose characters failed a random direction they think is right.
Regaining Your Bearings: There are several ways to become un-lost. First, if the characters successfully set a new course and follow it to the destination they’re trying to reach, they’re not lost anymore. Second, the characters through random movement might run into an unmistakable landmark. Third, if conditions suddenly improve—the fog lifts or the sun comes up—lost characters may attempt to set a new course, as described above, with a +4 bonus on the Survival check. Finally, magic may make their course clear.

FOREST TERRAIN
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.
Forest Terrain Features

Trees: The most important terrain element in a forest is the trees, obviously. A creature standing in the same square as a tree gains a +2 bonus to Armor Class and a +1 bonus on Reflex saves (these bonuses don’t stack with cover bonuses from other sources). 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 it provides concealment. Undergrowth increases the DC of Tumble and Move Silently checks by 2 because the leaves and branches get in the way. Heavy undergrowth costs 4 squares of movement to move into, and it provides concealment with a 30% miss chance (instead of the usual 20%). It increases the DC of Tumble and Move Silently checks by 5. Heavy undergrowth is easy to hide in, granting a +5 circumstance bonus on Hide 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 generally have rope bridges between them. To get to the treehouses, characters generally 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 are generally 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 will have occasional game trails.
Stealth and Detection in a Forest: In a sparse forest, the maximum distance at which a Spot 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 Hide skill in the forest. Logs and massive trees provide cover, which also makes hiding possible.
The background noise in the forest makes Listen checks more difficult, increasing the DC of the check by 2 per 10 feet, not 1 (but note that Move Silently is also more difficult in undergrowth).

Forest Fires (CR 6)
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 afire 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 Spot check, treating the fire as a Colossal creature (reducing the DC by 16). If all characters fail their Spot checks, the fire moves closer to them. They automatically see it when it closes to half the original distance.
Characters who are blinded or otherwise unable to make Spot 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 smolder. Characters overtaken by a forest fire may find the leading edge of the fire advancing away from them faster than they can keep up, trapping them deeper and deeper in 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 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. In addition, those wearing metal armor or coming 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 are then at risk once per minute thereafter (see Catching on Fire).
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. Also, smoke obscures vision, providing concealment to characters within it.

MARSH TERRAIN
Two categories of marsh exist: relatively dry moors and watery swamps. Both are often bordered by lakes (described in Aquatic Terrain, below), which effectively are a third category of terrain found in marshes.
The table below describes terrain features found in marshes.
Marsh Terrain Features

Bogs: 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 Tumble 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 Move Silently checks by 2.
Undergrowth: The bushes, rushes, and other tall grasses in marshes function as undergrowth does in a forest (see above). 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 may 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 bog before blundering in. A typical patch of quicksand is 20 feet in diameter; the momentum of a charging or running character carries him or her 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).
Characters below the surface of a bog 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 the victim fails to hold on, he must make a DC 15 Swim check immediately to stay above the surface. If both checks succeed, the victim is pulled 5 feet closer to safety.
Hedgerows: Common in moors, hedgerows are tangles of stones, soil, and thorny bushes. Narrow hedgerows function as low walls, and it takes 15 feet 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 moor, the maximum distance at which a Spot 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 hide in a marsh.
A marsh imposes no penalties on Listen checks, and using the Move Silently skill is more difficult in both undergrowth and bogs.

HILLS TERRAIN
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 Terrain Features

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.
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 Balance 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 Tumble 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 may 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, athough they rarely cover the landscape as they do in forests and marshes. Light undergrowth provides concealment and increases the DC of Tumble and Move Silently 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 Spot 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.
Hills don’t affect Listen or Move Silently checks.

MOUNTAIN TERRAIN
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 Terrain Features

Gradual and Steep Slopes: These function as described in Hills Terrain, above.
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,
above.
Scree: A field of shifting gravel, scree doesn’t affect speed, but it can be treacherous on a slope. The DC of Balance and Tumble 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 Move silently 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 Balance and Tumble checks on dense rubble increases by 5, and the DC of Move Silently 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. Beyond the entrance, 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 tree line, 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 may be covered in ice sheets (described below).
Stealth and Detection in Mountains: As a guideline, the maximum distance in mountain terrain at which a Spot 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 Listen checks increases by 1 per 20 feet between listener and source, not per 10 feet.
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 downslope by a character who makes a DC 20 Spot check, treating the avalanche as a Colossal creature. If all characters fail their Spot 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 Listen 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 may 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 (see below). 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 or she 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, and rock avalanches travel at a speed of 250 feet per round.

High altitude can be extremely fatiguing—or 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 may 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 nonacclimated 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 20,000 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 it 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.

DESERT TERRAIN
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 deserts), rocky desert (often temperate), and sandy desert (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. And 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 above 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 may contain either light undergrowth or an ice sheet, but not both.
Desert Terrain Features

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 Balance and Tumble checks there increases by 5. A DC 10 Balance 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 more difficult. The DC of Balance and Tumble 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 Balance and Tumble checks increases by 5, and the DC of Move Silently checks increases by 2.
Sand Dunes: Created by the action of wind on sand, 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 (described in Mountain Terrain, above). Sandy deserts sometimes have quicksand; this functions as described in Marsh Terrain, above, 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 Spot 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 spotting impossible. The presence of dunes in sandy deserts limits spotting distance to 6d6×10 feet.
The desert imposes neither bonuses nor penalties on Listen or Spot checks. The scarcity of undergrowth or other elements that offer concealment or cover makes hiding more difficult.

A sandstorm reduces visibility to 1d10×5 feet and provides a –4 penalty on Listen, Search, and Spot 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, to chafe skin and contaminate carried gear.

PLAINS TERRAIN
Plains come in three categories: farms, grasslands, and battlefields. Farms are common in settled areas, of course, 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 Terrain Features

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 above.
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, above), with the edges of the berm on the downhill side. Thus, a character crossing a two-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 Spot check for detecting the nearby presence of others can succeed is 6d6×40 feet, although the specifics of your map may restrict line of sight. Plains terrain provides no bonuses or penalties on Listen and Spot checks. Cover and concealment are not uncommon, so a good place of refuge is often nearby, if not right at hand.

AQUATIC TERRAIN
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 nonflowing water (such as lakes and oceans).
Flowing Water: 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, he arrests his motion by catching a rock, tree limb, or bottom snag—he 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, above).
Nonflowing Water: 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 as if they were flying with perfect maneuverability.
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 seafloor). Listen and Move Silently checks function normally underwater.
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 Armor Class, attack rolls, damage, and movement. In some cases a creature’s opponents may get a bonus on attacks. The effects are summarized in the accompanying table. They apply whenever a character is swimming, walking in chestdeep water, or walking along the bottom.
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. Landbound 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 Spellcraft 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 a Spellcraft check to make the fire spell usable underwater, the surface still blocks the spell’s line of effect.

In many wilderness areas, river floods are a common occurrence.
In spring, an enormous snowmelt can engorge the streams and rivers it feeds. Other catastrophic events such as massive rainstorms or the destruction of a dam can create floods as well.
During a flood, rivers become wider, deeper, and swifter. Assume that a river rises by 1d10+10 feet during the spring flood, and its width increases by a factor of 1d4×50%. Fords may disappear for days, bridges may be swept away, and even ferries might not be able to manage the crossing of a flooded river. A river in flood makes Swim checks one category harder (calm water becomes rough, and rough water becomes stormy). Rivers also become 50% swifter.

WEATHER
Sometimes weather can play an important role in an adventure.
Table: Random Weather is an appropriate weather table for general use, and can be used as a basis for a local weather tables. Terms on that table are defined as follows.
Calm: Wind speeds are light (0 to 10 mph).
Cold: Between 0° and 40° Fahrenheit during the day, 10 to 20 degrees colder at night.
Cold Snap: Lowers temperature by –10° F.
Downpour: Treat as rain (see Precipitation, below), but conceals as fog. Can create floods (see above). A downpour lasts for 2d4 hours.
Heat Wave: Raises temperature by +10° F.
Hot: Between 85° and 110° Fahrenheit during the day, 10 to 20 degrees colder at night.
Moderate: Between 40° and 60° Fahrenheit during the day, 10 to 20 degrees colder at night.
Powerful Storm (Windstorm/Blizzard/Hurricane/Tornado): Wind speeds are over 50 mph (see Table: Wind Effects). In addition, blizzards are accompanied by heavy snow (1d3 feet), and hurricanes are accompanied by downpours (see above). Windstorms last for 1d6 hours. Blizzards last for 1d3 days. Hurricanes can last for up to a week, but their major impact on characters will come in a 24-to-48-hour period when the center of the storm moves through their area. Tornadoes are very short-lived (1d6×10 minutes), typically forming as part of a thunderstorm system.
Precipitation: Roll d% to determine whether the precipitation is fog (01–30), rain/snow (31–90), or sleet/hail (91–00). Snow and sleet occur only when the temperature is 30° Fahrenheit or below. Most precipitation lasts for 2d4 hours. By contrast, hail lasts for only 1d20 minutes but usually accompanies 1d4 hours of rain.
Storm (Duststorm/Snowstorm/Thunderstorm): Wind speeds are severe (30 to 50 mph) and visibility is cut by three-quarters. Storms last for 2d4–1 hours. See Storms, below, for more details.
Warm: Between 60° and 85° Fahrenheit during the day, 10 to 20 degrees colder at night.
Windy: Wind speeds are moderate to strong (10 to 30 mph); see Table: Wind Effects on the following page.

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 a dense fog.
Most precipitation is rain, but in cold conditions it can manifest as snow, sleet, or hail. Precipitation of any kind followed by a cold snap in which the temperature dips from above freezing to 30° F or below may produce ice. Rain: Rain reduces visibility ranges by half, resulting in a –4 penalty on Spot and Search checks. It has the same effect on flames, ranged weapon attacks, and Listen checks as severe wind.
Snow: Falling snow has the same effects on visibility, ranged weapon attacks, and skill checks as rain, and it costs 2 squares of movement to enter a snow-covered square. 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, and it costs 4 squares of movement to enter a square covered with heavy snow. Heavy snow accompanied by strong or severe winds may result in snowdrifts 1d4×5 feet deep, especially in and around objects big enough to deflect the wind—a cabin or a large tent, for instance. There is a 10% chance that a heavy snowfall is accompanied by lightning (see Thunderstorm, below). Snow has the same effect on flames as moderate wind.
Sleet: Essentially frozen rain, sleet has the same effect as rain while falling (except that its chance to extinguish protected flames is 75%) and the same effect as snow once on the ground.
Hail: Hail does not reduce visibility, but the sound of falling hail makes Listen checks more difficult (–4 penalty). Sometimes (5% chance) hail can become large enough to deal 1 point of lethal damage (per storm) to anything in the open. Once on the ground, hail has the same effect on movement as snow.

The combined effects of precipitation (or dust) and wind that accompany all storms reduce visibility ranges by three quarters, imposing a –8 penalty on Spot, Search, and Listen checks. Storms make ranged weapon attacks impossible, except for those using siege weapons, which have a –4 penalty on attack rolls. They automatically extinguish candles, torches, and similar unprotected flames. They cause protected flames, such as those of lanterns, to dance wildly and have a 50% chance to extinguish these lights. See Table: Wind Effects for possible consequences to creatures caught outside without shelter during such a storm. Storms are divided into the following three types.
Duststorm (CR 3): These desert storms differ from other storms in that they have no precipitation. Instead, a duststorm blows fine grains of sand that obscure vision, smother unprotected flames, and can even choke protected flames (50% chance). Most duststorms are accompanied by severe winds and leave behind a deposit of 1d6 inches of sand. However, there is a 10% chance for a greater duststorm to be accompanied by windstorm-magnitude winds (see Table: Wind Effects). These greater duststorms deal 1d3 points of nonlethal damage each round to anyone caught out in the open without shelter and also pose a choking hazard (see Drowning—except that a character with a scarf or similar protection across her mouth and nose does not begin to choke until after a number of rounds equal to 10 × her Constitution score). Greater duststorms leave 2d3–1 feet of fine sand in their wake.
Snowstorm: In addition to the wind and precipitation common to other storms, snowstorms leave 1d6 inches of snow on the ground afterward.
Thunderstorm: In addition to wind and precipitation (usually rain, but sometimes also hail), thunderstorms are accompanied by lightning that can pose a hazard to characters without 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. Each bolt causes electricity damage equal to 1d10 eight-sided dice. One in ten thunderstorms is accompanied by a tornado (see below).
Powerful Storms: Very high winds and torrential precipitation reduce visibility to zero, making Spot, Search, and Listen checks and all ranged weapon attacks impossible. Unprotected flames are automatically extinguished, and protected flames have a 75% chance of being doused. Creatures caught in the area must make a DC 20 Fortitude save or face the effects based on the size of the creature (see Table: Wind Effects). Powerful storms are divided into the
following four types.
Windstorm: While accompanied by little or no precipitation, windstorms can cause considerable damage simply through the force of their wind.
Blizzard: The combination of high winds, heavy snow (typically 1d3 feet), and bitter cold make blizzards deadly for all who are unprepared for them.
Hurricane: In addition to very high winds and heavy rain, hurricanes are accompanied by floods. Most adventuring activity is impossible under such conditions.
Tornado: One in ten thunderstorms is accompanied by a tornado.

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

The wind can create a stinging spray of sand or dust, fan a large fire, heel over a small boat, and blow gases or vapors away. If powerful enough, it can even knock characters down (see Table: Wind Effects), interfere with ranged attacks, or impose penalties on some skill checks.
Light Wind: A gentle breeze, having little or no game effect.
Moderate Wind: A steady wind with a 50% chance of extinguishing small, unprotected flames, such as candles.
Strong Wind: Gusts that automatically extinguish unprotected flames (candles, torches, and the like). Such gusts impose a –2 penalty on ranged attack rolls and on Listen checks.
Severe Wind: In addition to automatically extinguishing any unprotected flames, winds of this magnitude cause protected flames (such as those of lanterns) to dance wildly and have a 50% chance of extinguishing these lights. Ranged weapon attacks and Listen checks are at a –4 penalty. This is the velocity of wind produced by a gust of wind spell.
Windstorm: Powerful enough to bring down branches if not whole trees, windstorms automatically extinguish unprotected flames and have a 75% chance of blowing out protected flames, such as those of lanterns. Ranged weapon attacks are impossible, and even siege weapons have a –4 penalty on attack rolls. Listen checks are at a –8 penalty due to the howling of the wind.
Hurricane-Force Wind: All flames are extinguished. Ranged attacks are impossible (except with siege weapons, which have a –8 penalty on attack rolls). Listen checks are impossible: All characters can hear is the roaring of the wind. Hurricane-force winds often fell trees.
Tornado (CR 10): All flames are extinguished. All ranged attacks are impossible (even with siege weapons), as are Listen checks. Instead of being blown away (see Table: Wind Effects), characters in close proximity to a tornado who fail their Fortitude saves are sucked toward the tornado. Those who come in contact with the actual funnel cloud are picked up and whirled around for 1d10 rounds, taking 6d6 points of damage per round, before being violently expelled (falling damage may 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 other similar forms of major destruction.

THE ENVIRONMENT
Environmental hazards specific to one kind of terrain (such as an avalanche, which occurs in the mountains) are described in Wilderness, above. Environmental hazards common to more than one setting are detailed below.

ACID EFFECTS
Corrosive acids deals 1d6 points of damage per round of exposure except in the case of total immersion (such as into a vat of acid), which deals 10d6 points of damage per round. An attack with acid, such as from a hurled vial or a monster’s spittle, counts as a round of exposure.
The fumes from most acids are inhaled poisons. Those who come close enough to a large body of acid to dunk a creature in it must make a DC 13 Fortitude save or take 1 point of Constitution damage. All such characters must make a second save 1 minute later or take another 1d4 points of Constitution damage.
Creatures immune to acid’s caustic properties might still drown in it if they are totally immersed (see Drowning).

COLD DANGERS
Cold and exposure deal nonlethal damage to the victim. This nonlethal damage cannot be recovered until the character gets out of the cold and warms up again. Once a character is rendered unconscious through the accumulation of nonlethal damage, the cold and exposure begins to deal lethal damage at the same rate.
An unprotected character in cold weather (below 40° F) must make a Fortitude save each hour (DC 15, + 1 per previous check) or take 1d6 points of nonlethal damage. A character who has the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well (see the skill Description).
In conditions of severe cold or exposure (below 0° F), an unprotected character must make a Fortitude save once every 10 minutes (DC 15, +1 per previous check), taking 1d6 points of nonlethal damage on each failed save. A character who has the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well (see the skill description). Characters wearing winter clothing only need check once per hour for cold and exposure damage.
A character who takes any nonlethal damage from cold or exposure is beset by frostbite or hypothermia (treat her as fatigued). These penalties end when the character recovers the nonlethal damage she took from the cold and exposure.
Extreme cold (below –20° F) deals 1d6 points of lethal damage per minute (no save). In addition, a character must make a Fortitude save (DC 15, +1 per previous check) or take 1d4 points of nonlethal damage. Those wearing metal armor or coming into contact with very cold metal are affected as if by a chill metal spell.

Characters walking on ice must spend 2 squares of movement to enter a square covered by ice, and the DC for Balance and Tumble checks increases by +5. Characters in prolonged contact with ice may run the risk of taking damage from severe cold (see above).

DARKNESS
Darkvision allows many characters and monsters to see perfectly well without any light at all, but characters with normal vision (or low-light vision, for that matter) can be rendered completely blind by putting out the lights. Torches or lanterns can be blown out by sudden gusts of subterranean wind, magical light sources can be dispelled or countered, or magical traps might create fields of impenetrable darkness.
In many cases, some characters or monsters might be able to see, while others are blinded. For purposes of the following points, a blinded creature is one who simply can’t see through the surrounding darkness.
—Creatures blinded by darkness lose the ability to deal extra damage due to precision (for example, a ranger’s favored enemy or a sneak attack).
—Blinded creatures are hampered in their movement, and pay 2 squares of movement per square moved into (double normal cost). Blinded creatures can’t run or charge.
—All opponents have total concealment from a blinded creature, so the blinded creature has a 50% miss chance in combat. A blinded creature must first pinpoint the location of an opponent in order to attack the right square; if the blinded creature launches an attack without pinpointing its foe, it attacks a random square within its reach. For ranged attacks or spells against a foe whose location is not pinpointed, roll to determine which adjacent square the blinded creature is facing; its attack is directed at the closest target that lies in that direction.
—A blinded creature loses its Dexterity adjustment to AC and takes a –2 penalty to AC.
—A blinded creature takes a –4 penalty on Search checks and most Strength- and Dexterity-based skill checks, including any with an armor check penalty. A creature blinded by darkness automatically fails any skill check relying on vision.
—Creatures blinded by darkness cannot use gaze attacks and are immune to gaze attacks.
A creature blinded by darkness can make a Listen check as a free action each round in order to locate foes (DC equal to opponents’ Move Silently checks). A successful check lets a blinded character hear an unseen creature “over there somewhere.” It’s almost impossible to pinpoint the location of an unseen creature. A Listen check that beats the DC by 20 reveals the unseen creature’s square (but the unseen creature still has total concealment from the blinded creature).
—A blinded creature can grope about to find unseen creatures. A character can make a touch attack with his hands or a weapon into two adjacent squares using a standard action. If an unseen target is in the designated square, there is a 50% miss chance on the touch attack. If successful, the groping character deals no damage but has pinpointed the unseen creature’s current location. (If the unseen creature moves, its location is once again unknown.)
—If a blinded creature is struck by an unseen foe, the blinded character pinpoints the location of the creature that struck him (until the unseen creature moves, of course). The only exception is if the unseen creature has a reach greater than 5 feet (in which case the blinded character knows the location of the unseen opponent, but has not pinpointed him) or uses a ranged attack (in which case, the blinded character knows the general direction of the foe, but not his location).
—A creature with the scent ability automatically pinpoints unseen creatures within 5 feet of its location.

FALLING
Falling Damage: The basic rule is simple: 1d6 points of damage per 10 feet fallen, to a maximum of 20d6.
If a character deliberately jumps instead of merely slipping or falling, the damage is the same but the first 1d6 is nonlethal damage. A DC 15 Jump check or DC 15 Tumble check allows the character to avoid any damage from the first 10 feet fallen and converts any damage from the second 10 feet to nonlethal damage. Thus, a character who slips from a ledge 30 feet up takes 3d6 damage. If the same character deliberately jumped, he takes 1d6 points of nonlethal damage and 2d6 points of lethal damage. And if the character leaps down with a successful Jump or Tumble check, he takes only 1d6 points of nonlethal damage and 1d6 points of lethal damage from the plunge.
Falls onto yielding surfaces (soft ground, mud) also convert the first 1d6 of damage to nonlethal damage. This reduction is cumulative with reduced damage due to deliberate jumps and the Jump skill.
Falling into Water: Falls into water are handled somewhat differently. If the water is at least 10 feet deep, the first 20 feet of falling do no damage. The next 20 feet do nonlethal damage (1d3 per 10-foot increment). Beyond that, falling damage is lethal damage (1d6 per additional 10-foot increment).
Characters who deliberately dive into water take no damage on a successful DC 15 Swim check or DC 15 Tumble check, so long as the water is at least 10 feet deep for every 30 feet fallen. However, 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.
Objects that fall upon characters deal damage based on their weight and the distance they have fallen.
For each 200 pounds of an object’s weight, the object deals 1d6 points of damage, provided it falls at least 10 feet. Distance also comes into play, adding an additional 1d6 points of damage for every 10-foot increment it falls beyond the first (to a maximum of 20d6 points of damage).
Objects smaller than 200 pounds also deal damage when dropped, but they must fall farther to deal the same damage. Use Table: Damage from Falling Objects to see how far an object of a given weight must drop to deal 1d6 points of damage.

For each additional increment an object falls, it deals an additional 1d6 points of damage.
Objects weighing less than 1 pound do not deal damage to those they land upon, no matter how far they have fallen.

HEAT DANGERS
Heat deals nonlethal damage that cannot be recovered until the character gets cooled off (reaches shade, survives until nightfall, gets doused in water, is targeted by endure elements, and so forth). Once rendered unconscious through the accumulation of nonlethal damage, the character begins to take lethal damage at the same rate.
A character in very hot conditions (above 90° F) must make a Fortitude saving throw each hour (DC 15, +1 for each previous check) or take 1d4 points of nonlethal damage. Characters wearing heavy clothing or armor of any sort take a –4 penalty on their saves. A character with the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well (see the skill description). Characters reduced to unconsciousness begin taking lethal damage (1d4 points per hour).
In severe heat (above 110° F), a character must make a Fortitude save once every 10 minutes (DC 15, +1 for each previous check) or take 1d4 points of nonlethal damage. Characters wearing heavy clothing or armor of any sort take a –4 penalty on their saves. A character with the Survival skill may receive a bonus on this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking lethal damage (1d4 points per each 10-minute period).
A character who takes any nonlethal damage from heat exposure now suffers from heatstroke and is fatigued.
These penalties end when the character recovers the nonlethal damage she took from the heat.
Extreme heat (air temperature over 140° F, fire, boiling water, lava) deals lethal damage. Breathing air in these temperatures deals 1d6 points of damage per minute (no save). In addition, a character must make a Fortitude save every 5 minutes (DC 15, +1 per previous check) or take 1d4 points of nonlethal damage. Those wearing heavy clothing or any sort of armor take a –4 penalty on their saves. In addition, those wearing metal armor or coming into contact with very hot metal are affected as if by a heat metal spell.
Boiling water deals 1d6 points of scalding damage, unless the character is fully immersed, in which case it deals 10d6 points of damage per round of exposure.

Characters exposed to burning oil, bonfires, and noninstantaneous magic fires might find their clothes, hair, or equipment on fire. Spells with an instantaneous duration don’t normally set a character on fire, since the heat and flame from these come and go in a flash.
Characters at risk of catching fire are allowed a DC 15 Reflex save to avoid this fate. If a character’s clothes or hair catch fire, he takes 1d6 points of damage immediately. In each subsequent round, the burning character must make another Reflex saving throw. Failure means he takes another 1d6 points of damage that round. Success means that the fire has gone out. (That is, once he succeeds on his saving throw, he’s no longer on fire.)
A character on fire may automatically extinguish the flames by jumping into enough water to douse himself. If no body of water is at hand, rolling on the ground or smothering the fire with cloaks or the like permits the character another save with a +4 bonus.
Those unlucky enough to have their clothes or equipment catch fire must make DC 15 Reflex saves for each item. Flammable items that fail take the same amount of damage as the character.

Lava or magma deals 2d6 points of damage per round of exposure, except in the case of total immersion (such as when a character falls into the crater of an active volcano), which deals 20d6 points of damage per round.
Damage from magma 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 points per round).
An immunity or resistance to fire serves as an immunity to lava or magma. However, a creature immune to fire might still drown if completely immersed in lava (see Drowning, below).

SMOKE EFFECTS
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 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 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 dehydration.
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 make a Constitution check each hour (DC 10, +1 for each previous check) or take 1d6 points of nonlethal damage.
A character can go without food for 3 days, in growing discomfort. After this time, the character must make a Constitution check each day (DC 10, +1 for each previous check) or take 1d6 points of nonlethal damage.
Characters who have taken nonlethal damage from lack of food or water are fatigued. Nonlethal 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
A character who has no air to breathe can hold her breath for 2 rounds per point of Constitution. After this period of time, the character must make a DC 10 Constitution check in order to continue holding her breath. The save must be repeated each round, with the DC increasing by +1 for each previous success.
When the character fails one of these Constitution checks, she begins to suffocate. In the first round, she falls unconscious (0 hit points). In the following round, she drops to –1 hit points and is dying. In the third round, she suffocates.
Slow Suffocation: A Medium character can breathe easily for 6 hours in a sealed chamber measuring 10 feet on a side. After that time, the character takes 1d6 points of nonlethal damage every 15 minutes. Each additional Medium character or significant fire source (a torch, for example) proportionally reduces the time the air will last.
Small characters consume half as much air as Medium characters. A larger volume of air, of course, lasts for a longer time.

WATER DANGERS
Any character can wade in relatively calm water that isn’t over his head, no check required. Similarly, swimming in calm water only requires skill checks with a DC of 10. Trained swimmers can just take 10. (Remember, however, that armor or heavy gear makes any attempt at swimming much more difficult. See the Swim skill description.)
By contrast, fast-moving water is much more dangerous. On a successful DC 15 Swim check or a DC 15 Strength check, it deals 1d3 points of nonlethal damage per round (1d6 points of lethal damage if flowing over rocks and cascades). On a failed check, the character must make another check that round to avoid going under.
Very deep water is not only generally pitch black, posing a navigational hazard, but worse, it deals water pressure damage of 1d6 points per minute for every 100 feet the character is below the surface. A successful Fortitude save (DC 15, +1 for each previous check) means the diver takes no damage in that minute. Very cold water deals 1d6 points of nonlethal damage from hypothermia per minute of exposure.

Any character can hold her breath for a number of rounds equal to twice her Constitution score. After this period of time, the character must make a DC 10 Constitution check every round in order to continue holding her breath. Each round, the DC increases by 1.
When the character finally fails her Constitution check, she begins to drown. In the first round, she falls unconscious (0 hp). In the following round, she drops to –1 hit points and is dying. In the third round, she drowns.
It is possible to drown in substances other than water, such as sand, quicksand, fine dust, and silos full of grain.