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Archives of Nethys

Archives of Nethys

Pathfinder RPG (1st Edition) Pathfinder RPG (2nd Edition) Starfinder RPG

Rules Index | GM Screen | Player's Guide
GM Core / Chapter 2: Building Games / Environment

Natural Disasters

Source GM Core pg. 95 2.0
Climate and environmental features can be a hindrance or long-term threat, but natural disasters represent acute danger, especially to those directly exposed to their fury. The damage in the following sections uses the categories in the Environmental Damage table on page 90.

Avalanches

Source GM Core pg. 96 2.0
Though the term avalanche specifically refers to a cascading flow of ice and snow down a mountain's slope, the same rules work for landslides, mudslides, and other similar disasters. Avalanches of wet snow usually travel up to 200 feet per round, though powdery snow can travel up to 10 times faster. Rockslides and mudslides are slower, sometimes even slow enough that a character might be able to outrun them.

An avalanche deals major or even massive bludgeoning damage to creatures and objects in its path. These victims are also buried under a significant mass. Creatures caught in an avalanche's path can attempt a Reflex save; if they succeed, they take only half the bludgeoning damage, and if they critically succeed, they also avoid being buried.

Burial

Source GM Core pg. 96 2.0
Buried creatures take minor bludgeoning damage each minute, and they potentially take minor cold damage if buried under an avalanche of snow. At the GM's discretion, creatures without a sufficient air pocket could also risk suffocation (Player Core 437). A buried creature is restrained and usually can't free itself.

Allies or bystanders can attempt to dig out a buried creature. Each creature digging clears roughly a 5-footby-5-foot square every 4 minutes with a successful Athletics check (or every 2 minutes on a critical success). Using shovels or other proper tools halves the time.

Blizzards

Source GM Core pg. 96 2.0
Blizzards combine cold weather, heavy snow, and strong winds. They don’t pose a single direct threat as other disasters do; instead, the combination of these factors all at once poses a substantial impediment to characters.

Collapses

Source GM Core pg. 96 2.0
Collapses and cave-ins occur when caverns or buildings fall, dumping tons of rock or other material on those caught below or inside them. Creatures under the collapse take major or massive bludgeoning damage and become buried, just as with an avalanche. Fortunately, collapses don’t spread unless they weaken the overall integrity of the area and lead to further collapses.

Earthquakes

Source GM Core pg. 96 2.0
Earthquakes often cause other natural disasters in the form of avalanches, collapses, floods, and tsunamis, but they also present unique threats such as fissures, soil liquefaction, and tremors.

Fissures

Source GM Core pg. 96 2.0
Fissures and other ground ruptures can destabilize structures, but more directly they lead to creatures taking bludgeoning damage from falling into a fissure.

Soil Liquefaction

Source GM Core pg. 96 2.0
Liquefaction occurs when granular particles shake to the point where they temporarily lose their solid form and act as liquids. When this happens to soil, it can cause creatures and even whole buildings to sink into the ground. You can use the earthquake spell for more specific rules, though that spell represents only one particular kind of localized quake.

Tremors

Source GM Core pg. 96 2.0
Tremors knock creatures prone, causing them to fall or careen into other objects, which can deal bludgeoning damage appropriate to the severity of the quake.

Floods

Source GM Core pg. 96 2.0
Though more gradual floods can damage structures and drown creatures, flash floods are similar to avalanches, except with a liquid mass instead of a solid one. Instead of burying creatures, a flash flood carries creatures and even massive objects away, buffeting the creatures and potentially drowning them. The drowning rules appear on page 437 of Player Core.

Sandstorms

Source GM Core pg. 96 2.0
Mild sandstorms and dust storms don’t present much more danger than a windy rainstorm, but they can cause damage to a creature’s lungs and spread diseases across long distances. Heavy sandstorms deal minor slashing damage each round to those exposed to the sand, force creatures to hold their breath to avoid suffocation, or both.

Tornadoes

Source GM Core pg. 96 2.0
In a tornado's path, wind conditions impose severe circumstance penalties, but creatures that would normally be blown away are instead picked up in the tornado's funnel, where they take massive bludgeoning damage from flying debris as they rise through the cone until they are eventually expelled (taking bludgeoning damage from falling).

Tornadoes usually travel around 300 feet per round (roughly 30 miles per hour). They normally travel a few miles before dissipating. Some tornadoes are stationary or travel much faster.

Tsunamis

Source GM Core pg. 96 2.0
Tsunamis present many of the same dangers as flash floods but are much larger and more destructive. Tsunami waves can reach 100 feet or more in height, wrecking buildings and creatures alike with massive bludgeoning damage from both the wave itself and debris pulled up along its path of destruction.

Volcanic Eruptions

Source GM Core pg. 97 2.0
Volcanic eruptions can contain any combination of ash, lava bombs, lava flows, pyroclastic flows, and vents.

Ash

Source GM Core pg. 97 2.0
Ash from volcanic eruptions is hot enough to cause minor fire damage each minute. It limits visibility like a thick fog and can make air unbreathable, requiring characters to hold their breath or suffocate (Player Core 437). Ash clouds generate ash lightning strikes, which typically deal moderate electricity damage but are very unlikely to hit an individual creature. Ash buildup on the ground creates areas of uneven ground, difficult terrain, or greater difficult terrain, and ash in the atmosphere can block the sun for weeks or even months, leading to colder temperatures and longer winters.

Lava Bombs

Source GM Core pg. 97 2.0
Pressure can launch lava into the air that falls as lava bombs: masses of lava that solidify as they fly and shatter on impact, dealing at least moderate bludgeoning damage and moderate fire damage.

Lava Flows

Source GM Core pg. 97 2.0
Lava flows are an iconic volcanic threat; they usually move between 5 and 60 feet per round over normal ground, so characters can often outrun them. However, flows can move up to 300 feet per round in a steep volcanic tube or channel. Lava emanates heat that deals minor fire damage even before it comes into contact with creatures, and immersion in lava deals massive fire damage each round.

Pyroclastic Flows

Source GM Core pg. 97 2.0
Mixes of hot gases and rock debris, pyroclastic flows spread much faster than lava, sometimes more than 4,000 feet per round. While cooler than the hottest lava, pyroclastic flows are capable of overwhelming entire settlements. They work like avalanches but deal half of their damage as fire damage.

Vents

Source GM Core pg. 97 2.0
Steam vents shoot from the ground, dealing moderate fire damage or more in a wide column. Acidic and poisonous gases released from beneath the surface can create wide areas of hazardous terrain that deals at least minor acid or poison damage.

Wildfires

Source GM Core pg. 97 2.0
Wildfires travel mainly along a front moving in a single direction. In a forest, the front can advance up to 70 feet per round (7 miles per hour). They can move up to twice as fast across plains due to a lack of shade and the relatively low humidity. Embers from the fire, carried by winds and rising hot air, can scatter, forming spot fires as far as 10 miles away from the main wildfire. Wildfires present three main threats: flames, heat, and smoke.

Flames

Source GM Core pg. 97 2.0
Flames are hazardous terrain, usually dealing moderate damage and potentially setting a character on fire, dealing moderate persistent fire damage. The flames from a small fire are often less dangerous than the advancing heat from the front of a large fire.

Heat

Source GM Core pg. 97 2.0
Wildfires increase the temperature in advance of the front, reaching nearly 1,500ºF at the fire’s arrival, as hot as some lava. This begins as minor fire damage every round at a reasonable distance from the front and increases to massive fire damage for someone within the wildfire.

Smoke

Source GM Core pg. 97 2.0
Wind can carry smoke far in front of the wildfire itself. Smoke imposes a circumstance penalty to visual Perception checks, depending on the thickness. It causes creatures viewed through significant amounts of smoke to be concealed, and it cuts off all visibility at half a mile or less. Near or within the wildfire, the combination of smoke and heated air require characters to hold their breath or suffocate (Player Core 437).