Adding Environmental Hazards to RPGs

Michael O. Varhola
During the most recent episode of our weekly “d-Infinity Live!” show, “The Road Goes Ever On,” we covered travel in role-playing games and one of the things we ended up discussing was environmental hazards that might pose problems for characters. In the course of answering a question from a reader, I talked about how it was important to me to incorporate natural hazards of various sorts into the 21 encounter tables, both nation-based and terrain-based, that appear in Skirmisher Publishing’s Swords of Kos Fantasy Campaign Setting (which is currently discounted 30% at DriveThruRPG and RPGNow). These include 14 nations, among them Aigyptos, Kos, and the Magocracy of Mesopotamia, and the various terrain types represented below. A free sample extracted from the campaign setting’s chapter on “Encounters” is also available at DriveThruRPG and its affiliated sites. 
In order to more fully share this concept with d-Infinity readers not already familiar with this detailed milieu, I have extracted the environmental encounters that appear on most of these tables and consolidated them into what appears here. In a couple of cases I have also included paragraphs corresponding to specific rather than general geographical areas, including Attica in mainland Greece, Amazonia on the northern shores of the Black Sea, the Italian Peninsula in the Republic of Rome, and Zueri in the heart of the Alps. As with the rest of the campaign setting, these environmental encounters are system-free and storytellers can apply to them whatever mechanics are associated with the game system they are using. From a mechanical point of view these can be treated in a particular game system the same way that appropriate traps or magical effects.
Amazonia: If near a river or coastline, this is a flood, and the Black Sea and/or surrounding rivers overflow their banks. Rushing waters destroy homes, drown fortifications, and reduce surrounding farmland to deep bogs. A flood is accompanied by d100 fleeing refugees and work crews of 2d10 able-bodies citizens and slaves working to build or maintain levies to mitigate the damage. There is a 5% chance the flood is caused by Poseidon’s wrath, with up to d6 hippocampi surging through the water and drowning those they find.
          If the party is on the steppes they experience a stampede. A herd of 20+d100 panicked animals (equal chance boar, gazelle, wild goat, or wild horses) come pounding across the plains, trampling everything in their path. There is an 80% chance the cause of the stampede is in pursuit of the herd (equal chance of 2d6 mounted hunters, 5+d10 wolves, d6 hill giantesses, d3 cyclops, or a dragon).
Attica: Weather-wise, Attica is prone to potent squalls rolling in off of the Aegean Sea and this can cause a variety of hazards. In coastal areas, marshlands, and low-lying plains, parties may have to deal with the effects of floods. In hills or plains, characters might be exposed to strong winds or the threat of lightning strikes. In mountainous areas, travelers might be exposed to possibly unseasonable but deadly snowstorms.
Italian Peninsula: The Italian Peninsula is dotted with volcanoes that can become active, fault lines that cause earthquakes, unstable soil that can become landslides, and is prone to flooding. A party adventuring in the Republic of Rome is at risk from any of these natural disasters, and several Roman settlements have been lost entirely to them over the ages.
Coastline: Heavy fog might cause characters to become lost, miss something they are looking for, or make it easier for a monster to catch them off guard. A tidal wave if on or near the shore, reef/sandbar (70%) or whirlpool (30%) if in a vessel at sea, or an undersea volcanic/thermal geyser eruption if underwater. These environmental hazards will destroy vessels and coastal villages in the case of the first two, and cause severe burns in the case of the last.
Desert: One of the most likely possibilities is a powerful sand storm that hits d4 minutes after observant characters have a chance to notice it and which will last 2d12 hours. Storytellers might also want to subject characters to the effects of extreme heat, lack of water, and other environmental factors that might affect their survival.
Forest: The party might stumble into an especially thick and overgrown area and as a result might be significantly slowed, have to turn back, or need to alter their route and, in the course of this, they could also end up making more noise than they would prefer. Other possibilities might include a forest fire, poisonous plants that sting party members that brush into them, quicksand in lowlying areas, or ravines that must be crossed via fallen trees or by some other means.
Hills: Hazards a party might face in hills are generally products of rain or other inclement weather. They include flash floods in ravines and low-lying areas; large rocks becoming dislodged and bouncing down from places above them while moving up or along slopes and possibly striking one or more characters; lightning strikes on hilltops or in exposed areas that might hit one or more characters in a party; and sinkholes covered by a thin layer of soil that characters walking over may fall into it and become trapped in.
Swamp/Marsh: Possibilities might include a rapidly-rising tide or surge in areas adjacent to the sea, an area of quicksand that the party might wander into, or even a lightning-sparked wildfire that rages through the vegetated areas of a swamp.
Mountains: Possibilities might include an avalanche, sudden blizzard, high winds, rock slide, or altitude sickness. Lightning will strike and might hit one or more characters in a party (50%) or a large rock (50%) will come bouncing down toward the party and might strike one or more of its members.
Mountains, Volcanic: On the slopes of an active volcanic, the ground underfoot might look solid but is a crust covering a flowing stream of lava that can severely burn anything coming into contact with it. On an associated pumice field, the friable ground might collapse and plummet into a lava tube that is d6x5 feet deep and any possible length in either direction.
Plains: Possibilities might include a wildfire that sweeps through the area the characters are in and must be outrun or otherwise survived by them, a patch of quicksand in a low-lying marshy area, lightning during a rainstorm, or a stampede.
Zueri: If near the mountains, this results in an avalanche. Tons of snow, ice, and rock tumble down the mountainside threatening to bury everything in the avalanche’s path. There is a 20% chance the avalanche uncovers something of value (equal chance each of silver, gold, platinum, gems, or lost treasure). There is an additional 20% chance the avalanche releases a dormant monster (equal chance each of earth elemental, fire elemental, giant, mammoth, or dinosaur).
          If the party is near a settlement, this results in a pandemic. Roll d100 to determine nature of the disease (01–20 coughing fits, 21–40 severe nausea, 41–60 intense fever, 61–80 intestinal distress, 81–90 the plague, 91–00 re-roll twice for a disease with multiple symptoms). There is a 60% chance any given establishment is open for business. Fields go unworked, attracting opportunistic scavengers (equal chance each of crows or rats). Every NPC has a 30% chance of carrying the disease, while only half of carriers display systems. The pandemic runs its coarse is 6+1d6 days.