3e SRD:Weather

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Weather

Rain, Snow, Sleet, and Hail

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 (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 (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.

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 (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. A tornado uproots trees, destroys buildings, and causes other similar forms of major destruction.

Table:Wind Effects

Object Wind Force	Wind Speed	Ranged Attacks (Normal/Siege Weapons*)	Creature Size**	Wind Effect on Creatures	Fort Save DC
Light	0–10 mph	—/—	Any	None	-
Moderate	11–20 mph	—/—	Any	None	-
Strong	21–30 mph	–2/—	Tiny or smaller	Knocked down	10
			Small or larger	None
Severe	31–50 mph	–4/—	Tiny	Blown away	15
			Small	Knocked down
			Medium-size	Checked
			Large or larger	None
Windstorm	51–74 mph	Impossible/–4	Small or smaller	Blown away	18
			Medium-size	Knocked down
			Large or Huge	Checked
			Gargantuan or Colossal	None
Hurricane	75–174 mph	Impossible/–8	Medium-size or smaller	Blown away	20
			Large	Knocked down
			Huge	Checked
			Gargantuan or Colossal	None
Tornado	175–300 mph	Impossible/impossible	Large or smaller	Blown away	30
			Huge	Knocked down
			Gargantuan or Colossal	Checked

*The siege weapon category includes ballista and catapult attacks as well as boulders tossed by giants.

**Flying or airborne creatures are treated as one size class smaller than their actual size, so an airborne Gargantuan dragon is treated as Huge for purposes of wind effects.

Checked: Creatures are unable to move forward against the force of the wind. Flying creatures are blown back 1d6x5 feet.

Knocked Down: Creatures are knocked prone by the force of the wind. Flying creatures are instead blown back 1d6x10 feet.

Blown Away: Creatures on the ground are knocked prone and rolled 1d4?10 feet, sustaining 1d4 points of subdual damage per 10 feet. Flying creatures are blown back 2d6?10 feet and sustain 2d6 points of subdual damage due to battering and buffeting.

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