One of the classic staples of fantasy role-playing games is their diverse ecology of monstrous enemies. Even the basic bestiaries for most games have hundreds of outlandish opponents for enterprising GMs to choose from, and most have supplementary books filled with additional enemies waiting to be unleashed.
However, one of the most omnipresent – and most dangerous – opponents your PCs can face isn’t found in any bestiary, and is often overlooked by GMs: the environment.
Environmental hazards are often brought out at two distinct levels of game-play. The first is when the PCs are low-level, and are usually unable to muster magic enough to defeat whatever hazards local conditions impose on them. The second is during high-level play, when adventures to alien worlds and distant dimensions present difficult terrain that catches the PCs off-guard.
In most cases, these environmental hazards tend to be fairly mild, and are often temporary conditions such as a snowstorm or a monsoon. Usually they impose some sort of movement penalty, along with perhaps a penalty to sight and, in extreme cases, mild but recurring damage. For the most part, they tend to present a mild inconvenience, but nothing that makes the PCs too concerned.
The reason that environmental effects are usually kept being nuisances, rather than major dangers, is because they possess a characteristic that sets them apart from all other obstacles the PCs face: invincibility. Unlike traps, the environment cannot be bypassed, short of leaving the area altogether. Unlike foes, the environment cannot be killed. The best the PCs can hope for is to generate an effect that ameliorates the penalties that the environment poses; otherwise their choices are reduced to leaving the area, or trying to succeed while taking recurring damage and/or persistent penalties.
Another reason that the environment is an under-utilized threat is that, more so than with monsters or traps, the environment needs to be justified against the context of the game world. Monsters tend to be itinerant, after all, and traps can remain for a very long time after being set, but you’re going to have a much harder time explaining why the gravity inside a particular dungeon is triple what it is everywhere else in the world.
However, just because environmental situations require a more thorough explanation doesn’t mean that they should be shied away from. Indeed, using a hostile environment to increase the challenge of a given adventure can make it all the more memorable when the PCs succeed (and, of course, they should be given greater rewards for their victory, since they accomplished it under unusually adverse conditions). Let’s take a look at some environmental factors and how they can be applied in your game world.
Temperature: Ambient temperature is one of the easiest ways to tweak the local environment. This can be as easy as saying that there’s an unusual, but perfectly natural, instance of freakishly warm or cold weather for a day or two. It can also be that you’re in an area where an extreme temperature is normal, such as in an arctic setting or a blasted desert. PCs in such settings will likely become fatigued much sooner than they would normally, and may even take damage if the temperature is exceptionally above or below the norm.
Pressure: Pressure is usually thought of in terms of deep-sea adventures, though it can apply if an airborne adventurer flies too high. Instances of extreme ambient pressure needn’t be limited to deep sea diving or high altitudes, though. Very low open-air areas (akin to Death Valley), for instance, will have high atmospheric pressure, whereas climbing a mountain – such as what Gandalf and the Fellowship tried to do when heading to Mordor, will bring low pressure-dangers into play.
The immediate dangers of high pressure are the crushing effect it can exert on characters, though in practice it’s rare to find such an environment without going underwater or to a place with a radically different atmosphere. Less extreme instances of high pressure are that it can trap heat, creating an area of high temperatures (see above). Low pressure, on the other hand, affects the atmospheric content, causing characters to receive less breathable air despite normal respiration, which in turn can affect cognition and stamina.
Atmosphere: Likewise, what’s in the air may be dangerous regardless of the local pressure. Many caves and sealed chambers – such as dungeons – have sealed pockets where poisonous, or flammable, gases can build up over time. When breached such chambers can make breathing difficult, to say nothing of what can happen when a fireball is thrown into such an environment.
Sudden influxes of gases may be immediately obvious if characters begin to cough and choke, but slow changes to the content of the air are much more insidious, as characters may begin to asphyxiate without realizing it. Even if the changes aren’t enough to be lethal, they can still be dangerous, as colorless and odorless toxins can have all kinds of effects on unwary characters.
Radioactivity: Radioactive dangers are often thought of as having no place in a fantasy setting. However, even in the real world there have been natural nuclear fission reactors, and high creatures that come from outer space or other planes can bring radioactive dangers with them. These are extremely dangerous simply because most characters won’t have a reliable way of detecting radioactivity, which can break down their biology, or treating it when it becomes apparent something’s wrong.
Gravity: Possibly the most obvious environmental aspect, save for temperature, is ambient gravity. Since gravity is generally uniform across a given world, PCs will generally search for a reason why it’s different in a given area. Magic will usually be the culprit here, unless they’ve accidentally wandered very far from home indeed.
Unlike pressure, changes in gravity will impact characters much more directly, as they’ll find their strength and speed increased or decreased proportionally to the change. For a good rule of thumb, increase characters’ carrying capacity by the inverse of the change in gravity (e.g. an area where gravity was three times what it normally is would result in a character only being able to carry one-third as much as normal). Likewise, characters endurance will be increased or decreased with lower or higher gravity, respectively, as their muscles have to exert lesser or greater influence to move.
It’s often said that heroes are only as great as the villains they face. That may be true, but the environment that they face them in certainly helps. The next time you’re designing an adventure for your characters, consider ways that you can tweak the environment to tweak the challenges your heroes will face. After all, which is more exciting? Facing down the Dark Lord of Evil, or facing him down on the edge of a radioactive volcano, spewing poisonous smoke as it threatens to erupt?