I’ve made the claim a few times that K20 doesn’t have a setting. That’s half true. By its very nature, K20 has to have something of a setting. Anytime you answer the question “Can I teleport to the moon” or “is the Earth hollow” you are defining the setting to an extend. This was touched on briefly in the religion entry, but it reoccurs when we talk about Geography and the Planes as well. We have to have a conversation about other planes, and the question of “How big is it” will arise. Mechanically, K20 has features that trigger off terrain, and as such we have to define terrain.
The Material Plane
The material plane is the realm a vast majority of most campaigns take place on. It is similar in most ways to Earth, and generally familiar to players. As there are hundreds of distinctions that can be drawn between a salt bog and a peat marsh, this list is abstracted to what we will consider the core terrain types. More specific ones obviously exist, but have no mechanical tags. Terrain is broken out into three main categories. Surface Terrain, Oceanic Terrain, and Underground Terrain.
The surface should be the most familiar terrain for your players. They have probably spent most of their time in the real world there, and generally have a good idea of what to expect.
Forest are a large area dominated by trees. Broadly speaking, these trees could be evergreen or deciduous, but the core principle is the same. Large areas of green and wooded earth. A forest differs from the plains in that it has high levels of tree cover and differs from a jungle in that forests are less dense. Forests generally allow for humans to walk through without effort, but still provide cover and limit long range sight.
Hill terrain is generally speaking the difference between a plain and a mountain. The terrain rises and falls frequently, but none of the changes in elevation are enough that a person could not be expected to cross multiple in a day. There are often patches of plains between them, and they usually border a mountain range of some sort.
Swamps are known for their thick, muddy waters and high density of plant life. This makes travel very challenging and provides great protection for ambush predators. Swamps are like forests or even jungles in terms of plant density, but their general lack of walkable terrain makes them stand out.
Beaches are a sandy terrain next to an ocean, lake, or other body of water. They have minimal tree cover but can include small brush. Larger beaches will have dunes like a desert.
Urban terrain is a standout. Unlike other terrain in this list, it is not naturally occurring. This does not mean it does not have life, as many animals and magical creatures have adapted and learned to thrive in these cities and towns. Additionally, of note, in a fantasy world there can be Oceanic and Subterranean Urban environments.
Artic terrain is defined by ice and snow. The ground is snow covered most of the year to varying degrees, and the ground consists of permafrost, permanently frozen underground ice.
Jungles are very similar to forests with one major exception. Tree density. Most jungles are almost impassibly dense, and any life that exists here must take that into account. Some form of Brachiation or flight is more common than simply walking from place to place.
Deserts are defined by their lack of water. Hot deserts are the most common type and consist of blistering heat and sandy dunes. Deserts have very little plant or animal life thanks to the lack of water, but many hardy or magical creatures live there, and some even thrive. Cold Deserts exist but are more accurately modeled by the artic terrain.
Plains consist of relatively flat, low brush and tall grass. These tend to make up the most habitable terrain on the surface, and many farmers flock here.
Mountains differ from hills in scope. Whereas a walker may cover a series of hills in a day at leisurely pace, crossing a single mountain is an expedition. These are high, treacherous peaks that for all intents and purposes form a border against armies or the common folk. The prepared adventure may be able to cross, but most normal folk simply treat them as walls.
While the surface is certainly the most familiar terrain grouping for most players and characters, the Ocean is the most plentiful. It covers between 2/3 and 3/4 of the planet’s surface and is home to an astonishing number of species. Most of its terrain is organized by depth.
The Waves terrain mostly consists of the surface of the ocean, and is the home of boats, sailors, and a variety of birds.
The sunlight zone is named, because this is the maximum depth of the ocean where sun can penetrate. It has natural light and is relatively warm. This realm ranges from 0-700ft in depth, and houses most air breathing aquatic animals. Most aquatic plants live at this depth and begin to fade away the deeper you get.
The twilight zone is the realm between 700 and 3,000ft in depth. Occasionally rays of light may penetrate, but this is the first true aquatic realm. Light and heat are scarce, and life begins to take on an unfamiliar nature to surface dwellers. Most aquatic civilizations with positive relations with the surface have settlements at this depth.
The Midnight Zone ranges from 3,000 to 12,000ft and is utterly black. Light from above does not penetrate and vision is all but impossible. This zone is home to many bioluminescent creatures. Societies at this depth rarely meet the surface world and usually view it as a threat.
The Abyssal Zone is between 12,000 and 20,000ft consisting of near freezing water and immense pressure. Most of the ocean’s floor resides at this level, and upon it lay great ancient cities. Most life here is invertebrate, due to the pressure. Societies here rarely encounter the surface world and may even consider it a myth.
The Trenches are the lowest points of the ocean, jutting from 20,000ft to an unknown depth. Life in the trenches is sparse and rare, but generally magical in nature. Societies are unheard of, but possible.
Underground is not usually thought of as a terrain, but in fantasy games it is commonly traversed. While tempting to call it “dark and brown” there is a variety of life and colors to be found in the stonework and creatures that live there.
The barrens are cool dry caves. This is your stereotypical image of a cave, with little of interest aside from stone. Due to the lack of water in a barren, they function like a desert in the underground ecosystem. A large barrier of challenging to traverse terrain. Based on the stone makeup of the area, a barren’s walls and floor will be a combination of green, brown, red, or grays.
Fungal Troops are the inverse of a barren. They are hot, damp, moist, lit by glowing fungus, and populated by dense mushrooms and moss. The fungal troop is hotly contested by any underdark society for its natural benefits. Food, lumber, useful molds, and tamable animals.
The maze is analogous to a mountain in function, even if the form is almost the opposite. Usually naturally occurring, but occasionally created, a maze is a rat’s nest of crossing, intertwined channels and tunnels seemingly designed to extend the duration of travel.
Veins occur around valuable minerals, usually gemstones or precious metals. A vein is a section of exposed gems or metals in what would otherwise be a barren or a maze. Veins, once found, are highly contested, and often serve as the bedrock for a city or civilization.