Environmental Effects#

Environmental effects are a tool for the GM to add texture and tension to encounters. They are not meant to be tracked in every single encounter — most weather and terrain is narrative flavor. The GM should only apply mechanical effects when the environment is severe enough to meaningfully affect the characters or when it would make a situation more interesting.

Environmental effects do two things: non-damaging effects alter decision rolls through advantage and disadvantage, while exposure effects threaten a character’s health through conditions, wounds, and VIT damage.

Exposure Intervals#

When a character is exposed to dangerous environment without adequate protection, the GM sets two things: an exposure interval (how often the environment takes its toll) and a FORT target (how hard it is to resist). Examples using severity descriptors are provided in the following chart:

At the end of each exposure interval affected characters must make a FORT check. Failure leads to conditions, wounds, and/or VIT damage as described by the type of environment. Success avoids harm, but raises the target of the FORT check by 1 for the next interval if the character remains exposed.

Each type of environemtnal effect has its own exposure concequences tied to these FORT checks. The effects of a high heat environment and a room of toxic fumes are different, but the exposure intervals work the same.

Heat & Cold#

High and low temperature are the most common environmental threats and sources of exposure damage.

Appropriate protection — Full exposure resistance to the appropriate damage type (burn or cold), or protective items such as warm clothing, shade and water, or shelter — can reduce or eliminate the need for checks entirely. The GM may also shorten the interval or raise the target as conditions worsen.

Exposure — At the end of each exposure interval, an unprotected character makes a FORT check:

• First Failure — The character gains the fatigued condition. A character who is already fatigued from any source skips this step as if suffering fron their second failure.
• Second Failure — The character suffers a minor burn wound. Cold injuries such as frostbite are treated mechanically as burns for all purposes.
• Third and Subsequent Failures — The character suffers 1 VIT loss from each failure and the GM may worsen untreated wounds to major if the situation calls for it.

If VIT reaches 0 from exposure the character falls unconscious. Exposure VIT loss typicallly begins as non-lethal for mild and harsh effects, but the GM may rule otherwise if rescue is not possible or if succumbing to severe effects. An unconscious character who remains exposed may continue to deteriorate at the GM’s discretion with further FORT checks, with continued failure resulting in the dying condition.

Removing a character from the hazardous environment stops this progression. The fatigued and unconscious conditions from hrat/cold exposure are removed individually with 1 hour of rest in a safe environment per condition. Burn wounds and the dying condition must be dressed and healed normally.

Example: The party is crossing a frozen mountain pass in a snowstorm. The GM sets the interval at 10 minutes with a target 8 FORT check. Mara, who left her heavy coat behind to save carry weight, fails her first check and becomes fatigued. Ten minutes later she fails again — receiving a minor burn wound from frostbite. The party decides to set up camp before things get worse, and are able to shelter by a fire. After an hour, Mara’s fatigue is healed but her wound still needs attention.

Toxic Atmosphere#

Mild airborne irritants such as thin smoke, airborne particulates, or foul air pose and sometimes difficult to detect threat.

Exposure — At the end of each exposure interval, an unprotected character makes a FORT check:

• First Failure — The character gains the shaken condition brought on by coughing fits.
• Second Failure — The character gains the sick condition for as long as the character is exposed and 1d4 rounds after.
• Third and Subsequent Failures — The character suffers 1 VIT loss from each subsequent failure.

Unbreathable Air — Characters exposed to an environment they cannot breathe in at all gain the asphyxiating condition immediately. Not all toxic environments are unbreathable and not all unbreathable environments are toxic.

Visibility#

Smoke, fog, darkness, dust, heavy rain, and similar conditions limit what characters can see. Visibility effects alter decision rolls rather than causing direct harm, amd do not rely on exposure intervals. The GM decides the severity based on the situation.

Obscured — Vision is partially blocked. Light fog, rain, dim lighting, thin smoke. Ranged attacks and perception-related checks suffer minor disadvantage.

Heavily Obscured — Vision is almost entirely blocked, often limited to 10ft or less. Dense fog, heavy smoke, total darkness, blinding storms. Ranged attacks and perception-related checks suffer major disadvantage. Characters may need to make decision rolls to navigate around hazards.

When both sides of an opposed roll are equally affected by visibility, no change is made — the disadvantage cancels out. However, surprise attacks become easier to set up when neither side can see. The GM should consider whether characters can detect each other through sound, smell, or other means.

Weather and Terrain — Heavy storms may combine visibility penalties with difficult terrain (reducing movement speed) and may interrupt multi-turn actions. Characters on exposed or elevated terrain during a storm may need to make AGI checks to keep their footing.

It is worth noting thay the rules for visibility and terrain are not a separate set of rules — they are immersive applications of the existing advantage, disadvantage, and multi-turn action interruption rules found in Combat.

Example: A smoke grenade fills a corridor. Attackers firing into the smoke suffer major disadvantage. Two characters fighting in melee inside the smoke are both equally blinded — their opposed rolls are unchanged, but a third character sneaking up on either of them could make a surprise attack.

Extreme Environments#

The core Environmental Effects rules cover weather and conditions that wear characters down over time. Extreme environments — the surface of a volcanic moon, the vacuum of space, the ruins of a breached reactor — skip the slow buildup entirely. In these instances, at the end of each exposure interval an unprotected character suffers 1 VIT loss. No FORT check is made — the environment is beyond what the body can resist.

The GM sets the interval based on proximity and intensity: 1 round for direct contact or close proximity, 1 minute for ambient exposure, or longer for low-level unavoidable hazards like residual radiation.

Wounds are applied normally when VIT thresholds are met. When VIT reaches 0 rules for lethal damage apply.

Resistance — Extreme and exposure effects bypasses partial resistance. Full resistance provides immunity to exposure effects and halves extreme damage, providing ample protection as long as further damage is avoided. Full Resistance can be bypassed if both an extreme exposure event and a damaging event of the same type occure. In practice, this means characters using special heat shielded suits to protect themselves on a volcanic moon would be protected from the extreme exposure, but if lava erupted below them they would still be subject to damage and take half. See Damage Resistance for more on resistances.

Vacuum#

The hazards of a vacuum deserve special mention because it combines multiple items simultaneously. A character exposed to the vacuum of space without a sealed, pressurized suit immediately gains the asphyxiating condition and suffers extreme cold exposure.

Decompression — Sudden decompression (such as a hull breach) may also cause physical trauma. The size of the breach determines the amount of force and the amount of area affected by a decompression. Typically, Characters a within a radius equal to twice the size of the breach must succeed on a target 10 FORT check or suffer 1 VIT loss and a minor wound (typically a contusion or sprain). The GM may increase the target for explosive decompression.

Equipment — A pressurized suit prevents asphyxiation and decompression trauma but provides no thermal protection. A full space suit handles all three — asphyxiation, decompression, and cold resistance — but oxygen is still limited (1 hour for most suits, 5 hours for the EVA Suit). When oxygen runs out, asphyxiating begins regardless of suit integrity.

Radiation#

Unlike heat and cold, radiation exposure may not be immediately obvious to the characters. The GM may track radiation damage privately and reveal symptoms — the sick or fatigued conditions, unexplained burns — as they accumulate. Characters with detection equipment such as a Hazard HUD would know they are in danger. Low-level radiation zones may use longer intervals of 10 minutes or more, while active reactor breaches and similar sources use intervals of 1 round to 1 minute.

Specialized Equipment#

Standard space suits, pressurized suits, and field medical supplies like ARA-5 are designed for the expected hazards of space travel. Extreme environments push beyond what standard equipment is built for. GMs are encouraged to introduce specialized gear — thermal shielding, hardened radiation suits, cryo-rated armor — when the adventure calls for it. Such equipment might be purchased, salvaged, modified, or improvised, and its availability can drive meaningful preparation and decision-making at the table.