Environment

Water

Any character can wade in relatively calm water that isn’t over his head, no check required.

Swimming in calm water only requires skill checks with a DC of 10. Trained swimmers can just take 10.

Fast-moving water is much more dangerous. On a successful Swim or Strength check (DC 15), it deals 1d3 points of subdual damage per round (1d6 points of normal damage if flowing over rocks and cascades). On a failed check, the character must make another check that round to avoid going under. If the character goes under, the character is drowning.

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 saving throw (DC 15, +1 for each previous check) means the diver takes no damage in that minute.

Very cold water deals 1d6 points of subdual damage from hypothermia per minute of exposure.

Drowning

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 Constitution check (DC 10) 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 dies.

It is possible to drown in substances other than water, such as sand, quicksand, fine dust, and silos full of grain.

Starvation and Thirst

In normal climates, Medium-size 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 sustain 1d6 points of subdual 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 sustain 1d6 points of subdual damage.

Characters who have taken subdual damage from lack of food or water are fatigued. Subdual 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.

Heat

Heat deals subdual damage that cannot be recovered until the character gets cooled off. Once rendered unconscious through the accumulation of subdual damage, the character begins to take normal 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 sustain 1d4 points of subdual damage. Characters wearing heavy clothing or armor of any sort have a -4 penalty to their saves. A character with the Wilderness Lore skill may receive a bonus to this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking normal damage (1d4 points per hour).

In extreme heat (above 110° F), a character must make a Fortitude save once every 10 minutes (DC 15, +1 for each previous check) or sustain 1d4 points of subdual damage. Characters wearing heavy clothing or armor of any sort have a -4 penalty to their saving throws. A character with the Wilderness Lore skill may receive a bonus to this saving throw and may be able to apply this bonus to other characters as well. Characters reduced to unconsciousness begin taking normal damage (1d4 points per each 10-minute period).

A character who sustains any subdual damage from heat exposure now suffers from heatstroke and is fatigued. These penalties end when the character recovers the subdual damage she took from the heat.

Abysmal heat (air temperature over 140° F, fire, boiling water, lava) deals normal 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 sustain 1d4 points of subdual damage. Those wearing heavy clothing or any sort of armor have a -4 penalty to 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.

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.

Catching on Fire

Characters at risk of catching fire are allowed a Reflex saving throw (DC 15) 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 at 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 Reflex saving throws (DC 15) for each item. Flammable items that fail sustain the same amount of damage as the character.

Cold

Cold and exposure deal subdual damage to the victim. This subdual 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 subdual damage, the cold and exposure begins to deal normal damage at the same rate.

An unprotected character in cold weather (below 40° F) must make a Fortitude saving throw each hour (DC 15, + 1 per previous check) or sustain 1d6 points of subdual damage. A character who has the Wilderness Lore skill may receive a bonus to this saving throw and may be able to apply this bonus to other characters as well.

In conditions of extreme 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 subdual damage on each failed save. A character who has the Wilderness Lore skill may receive a bonus to this saving throw and may be able to apply this bonus to other characters as well. Characters wearing winter clothing only need check once per hour for cold and exposure damage.

A character who sustains any subdual damage from cold or exposure suffers from frostbite or hypothermia and is fatigued. These penalties end when the character recovers the subdual damage she took from the cold and exposure.

Weather Hazards

Winds: Winds 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, they can even knock characters down (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 to ranged attacks and to 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 the 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 to attack. 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 to attack). Listen checks are impossible: All characters can hear is the roaring of the wind. Hurricane-force winds often fell trees.
• Tornado: 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. A tornado uproots trees, destroys buildings, and causes other similar forms of major destruction.

Precipitation: Most precipitation is in the form of 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 to Spot and Search checks. It has the same effect on flames, ranged weapon attacks, and Listen checks as severe wind (see above).
• Snow: While falling, snow reduces visibility as rain (–4 penalty to ranged weapon attacks, Spot checks, and Search checks). Once on the ground, it reduces movement by half. Snow has the same effect on flames as moderate wind (see above).
• 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 damage (per storm) to anything in the open. Once on the ground, hail has the same effect on movement as snow.

Storms: The combined effects of precipitation (or dust) and wind that accompany all storms reduce visibility ranges by three quarters, imposing a –8 penalty to all Spot, Search, and Listen checks. Storms make ranged weapon attacks impossible, except for with siege weapons, which have a –4 penalty to attack. 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: 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 (see above) and leave behind a deposit of 1d6 inches of sand. However, there is a 10% chance of a greater duststorm accompanied by windstorm-magnitude winds (see above and Table: Wind Effects). These greater duststorms deal 1d3 points of subdual damage each round on anyone caught out in the open without shelter and also pose a choking hazard (see The Drowning Rule—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 ten times 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 electrical 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 and Search rolls, Listen checks, and all ranged weapon attacks impossible. Unprotected flames are automatically extinguished, and even protected flames have a 75% chance of being doused. Creatures caught in the area can make a Fortitude saving throw (DC 20) or face the following effects based on the size of the creature. 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 (see Table: Wind Effects).
• Blizzard: The combination of high winds (see Table: Wind Effects), 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 (see Table: Wind Effects) and heavy rain, hurricanes are accompanied by flash floods (see below). Most adventuring activity is impossible under such conditions.
• Tornado: One in ten thunderstorms is accompanied by a tornado (see Table: Wind Effects).

Fog: 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 within 5 feet have one-half concealment (attacks by or against them have a 20% miss chance).

Flash Floods: Runoff from heavy rain forces creatures in its path to make a Fortitude save (DC 15). Large or smaller creatures who fail the save are swept away by the rushing water, taking 1d6 points of subdual damage per round (1d3 points on a successful Swim check). Huge creatures who fail are knocked down and face potential drowning. Gargantuan and Colossal creatures are checked, but they only drown if the waters rise above their heads.

Other Dangers

Use the following guidelines to cover the other sorts of dangers a character can face.

Acid

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 inhalant poisons. Those who come close enough to a large body of acid to dunk a creature in it must make a Fortitude save (DC 13) or take 1 point of temporary Constitution damage. All such characters must make a second save 1 minute later or take another 1d4 points of temporary Constitution damage.

Creatures immune to acid’s caustic properties might still drown in it if they are totally immersed.

Ice

Characters walking on ice must make Balance checks (DC 15) to avoid slipping and falling. Over long distances, a character must make a check each minute. Characters in prolonged contact with ice may run the risk of cold damage.

Lack of Air/High Altitude

Characters in conditions of low oxygen, such as on top of a mountain, must roll a Fortitude saving throw each hour (DC 15, +1 per previous check), taking 1d6 points of subdual damage each time they fail.

A character who sustains any subdual damage from lack of oxygen is automatically fatigued. These penalties end when the character recovers the subdual damage he took from low oxygen.

Altitude Sickness: Long-term oxygen deprivation due to high altitude affects mental and physical ability scores. After each 6-hour period a character spends at an altitude of over 20,000 feet, he must make a Fortitude save (DC 15, +1 per previous check) or take 1 point of temporary damage to all ability scores.

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 Constitution check (DC 10) 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 hp). In the following round, she drops to –1 hit points and is dying. In the third round, she suffocates.

Slow Suffocation: A Medium-size 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 subdual damage every 15 minutes. Each additional Medium-size character or significant fire source (a torch, for example) proportionally reduces the time the air will last. Thus, two people can last for 3 hours, after which they each take 1d6 points per 15 minutes. If they have a torch (equivalent to another Medium-size character in terms of the air it uses), the air runs out in only 2 hours.

Small characters consume half as much air as Medium-size characters. A larger volume of air, of course, lasts for a longer time. So, for instance, if two humans and a gnome are in a sealed chamber measuring 20 feet by 20 feet by 10 feet, and they have a torch, the air will last almost 7 hours (6 hours/3.5 people and torches x 4 10-ft. cubes = 6.86 hours).

Lava

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 heat or fire serves as an immunity to lava or magma. However, a creature immune to heat might still drown if completely immersed in lava.

Smoke

A character who breathes heavy smoke must make a Fortitude saving throw each round (DC 15, +1 per previous check) or spend that round choking and coughing. A character who chokes for two consecutive rounds takes 1d6 points of subdual damage.

Smoke obscures vision, giving one-half concealment (20% miss chance) to characters within it.

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. For example, since a 30-pound metal sphere must fall 50 feet to deal damage (1d6 points of damage), such a sphere that fell 150 feet would deal 3d6 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.