Storms

Running a Rainstorm:

Rainstorms can slow or halt travel and turn trails and tracks into quagmires. Travelling in a rainstorm - while not necessarily dangerous - can be miserable.

Rainstorms can have the following effects:

Visibility: Visibility in a rainstorm is halved, resulting in a penalty on Perception Checks; rain imposes a -2 penalty on Ranged Attacks, and extinguishes unprotected flames.

Wind: The wind increases so that it reduces visibility by 3/4, resulting in a -8 penalty  to Perception Checks, These storms also render ranged attacks impossible (with the exception for Siege Weapons - which take a -4 penalty on Attack Rolls), Automatically extinguish  unprotected flames and have a 50% chance to extinguish protected flames (hooded lanterns).

Thunderstorms: have the additional hazard of lightening, which strikes once per minute in a 1 hour period at the storm's center (decreasing as the PC moves away from the center): each bolt causes between 4D8 and 10D8 lightening damage.

Colder Climates: Freezing rain or hail sometimes accompanies or replaces rain in a storm, where it imposes a penalty on sound-based Perception Checks (-3 Freezing Rain/ -4 Hail) and creates difficult terrain where it falls. Hail has a 5% chance to be large enough to deal 1 damage to unprotected creatures.

Possible Tornado: Each thunderstorm has a 10% chance of producing a tornado (extinguishes all flames, renders all Ranged Attacks impossible - including Siege weapons, renders all sound based Perception Checks impossible and pulls creatures who fail a Strength Save into the funnel - dealing 6D6 damage per round for 1D10 rounds before expelling the creature and dealing falling damage).

Running a Snow Storm

Snowstorms dump a lot of snow over an area in a short amount of time. This hinders travel, can lead to travelers getting lost and – in extreme cases – can kill those caught out in them.

Snowstorms have the following game effects:

Wind: The wind increases so that it reduces visibility by 3/4, resulting in a -8 penalty  to Perception Checks, These storms also render ranged attacks impossible (with the exception for Siege Weapons - which take a -4 penalty on Attack Rolls), Automatically extinguish  unprotected flames and have a 50% chance to extinguish protected flames (hooded lanterns).

Normal Snowfall: Visibility in a rainstorm is halved, resulting in a penalty on Perception Checks; rain imposes a -2 penalty on Ranged Attacks, and extinguishes unprotected flames. A days worth of snowfall leaves 1D6 inches of snowfall and cost 1 foot of movement for every 3 feet moved.

Heavy Snowfall: Same penalties as Normal Snow but also grants 1/4 Cover against Ranged Attacks. A day snowfall leaves 1D4 feet of snow and becomes difficult terrain.

Sleet: Freezing rain or hail sometimes accompanies or replaces snow in a storm, where it imposes a penalty on sound-based Perception Checks (-3 Freezing Rain/ -4 Hail) and creates difficult terrain where it falls. Has a 5% chance to be large enough to deal Damage (Freezing Rain: 1 damage / Hail: 1d4 bludgeoning) to unprotected creatures. 

Blizzard: Same Penalties as Wind and Heavy Snow Combined (For an Ice Storm combine Wind and Sleet). For every half hour PC must make a Constitution save (DC12, +1 for each subsequent half hour) taking 1D4 Cold Damage and 1 point of exhaustion on a failed save.

Running a Windstorm

Powerful windstorms can damage or destroy property and make travel impossible. Windstorms have the following game effects:

Gusts of Wind: Windstorms rarely occur with precipitation, but gusts of wind during thunderstorms can hit extremes approaching a windstorm’s power (or exceed them when a thunderstorm spawns a tornado).

Windstorm/Duststorm: The wind increases so that it reduces visibility by 3/4, resulting in a -8 penalty  to Perception Checks, These storms also render ranged attacks impossible (with the exception for Siege Weapons - which take a -4 penalty on Attack Rolls), Automatically extinguish  unprotected flames and have a 50% chance to extinguish protected flames (hooded lanterns).

Great Duststorm: Same Penalties as Windstorm/Duststorm but for every half hour the PC must make a Constitution save (DC12, +1 for each subsequent half hour) taking 1D4 Force Damage and 1 point of exhaustion on a failed save.

Flying Creatures: Medium or smaller creatures attempting to move against windstorm‐force winds must make a DC 10 Strength check, windstorm‐magnitude winds knock Small or smaller creatures to the ground prone and push them 1d4 x 10 feet (dealing 1D4 points of fall damage per 10 feet), unless they make a DC 15 Dexterity Check; for airborne creatures of size Small or smaller, the wind blows them back 2d6 x 10 feet and deals 2d6 points of Force Damage (which a flying creature can avoid with a successful DC 15 Dexterity Check).

Hurricane: Hurricane force winds act like windstorm‐force winds with the following exceptions: they impose a ‐8 penalty on siege weapon attacks, render Perception checks based on sound impossible, imposes a ‐8 penalty on Dexterity Checks for Large or Medium creatures, and smaller creatures must succeed a DC15 Strength Check or take 1D6 Force Damage/round and be pushed 1D100 feet.

Tornado: Each thunderstorm has a 10% chance of producing a tornado (extinguishes all flames, renders all Ranged Attacks impossible - including Siege weapons, renders all sound based Perception Checks impossible and pulls creatures who fail a Strength Save into the funnel - dealing 6D6 damage per round for 1D10 rounds before expelling the creature and dealing falling damage).