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 mexposure effects threaten a character’s health through conditions, wounds, and VIT damage.

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. 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 (−3).

Heavily Obscured — Vision is almost entirely blocked. Dense fog, heavy smoke, total darkness, blinding storms. Ranged attacks and perception-related checks suffer major disadvantage (−1 decision die). 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 FORT or 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 Health & 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.

Heat & Cold#

Temperature extremes are the most common environmental threat and source of exposure damage. When a character is exposed to dangerous heat or cold 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).

Appropriate protection — A full 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.

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.

Second Failures — 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 each failure and the GM may worsen 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, but the GM may rule otherwise if rescue is not possible. An unconscious character who remains exposed may continue to deteriorate at the GM’s discretion with further FORT checks, and continued failure resulting in the dying condition.

Removing a character from the hazardous environment stops this progression. Each individual condition from exposure (fatugured, unconscious, dying) is removed with 1 hour of rest in a safe environment per condition. Burn wounds 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#

Toxic atmospheres use existing conditions. Mild irritants — thin smoke, airborne particulates, foul air — cause the sick condition for as long as the character is exposed and 1d4 rounds after. Unbreathable air — vacuum, dense toxic fumes, oxygen deprivation — causes the asphyxiating condition immediately, following its existing rules. Some atmospheres are both toxic and breathable; for prolonged exposure to these, the GM may escalate from sick to fatigued and then to VIT damage, following the same pattern as heat and cold.

Environmental Injuries#

The following extends the Common Injuries table in Wounds & Conditions:

Exteme Environments#

Sci-Fi Module Addition

Extreme Environments#

Sci-Fi Module Additon

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 hazards like residual radiation.

Wounds are applied normally when VIT thresholds are met. When VIT reaches 0 the, rules for lethal damahe often apply.

Resistance — Extreme and exposure effects bypasses partial resistance. Full resistance is immune to exposure effects, and halves extreme damage. Howevever, 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. Damage Resistance for more on resistances.

Extreme Hazard Reference#

The table below summarizes each hazard type. All follow the same core rule above — the differences are in damage type and associated conditions.

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#

Radiation also warrants a note beyond the table. 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.