When travelling through the lands, it is very important for the adventurer to know the terrain. Each terrain has different advantages and problems, each hinders the traveller in a different way and has its own dangers. Therefore here an overview of the forms of terrain found in the lands.
Terrain of the Land
Vast grasslands such as the High Steppes, the isle of New Magincia or bigger stretches of the southern part of Britannia's main continent pose little to no hindrance or threat to the adventurer. Dangers are far and few between and early to see.
The vegetation of the brush is much denser than that of the grassland. The grass is here often as high as half a man (sometimes even higher) and low scrub growth and bushes add to the terrain, making travel through it more difficult, slowing down the adventurer. If it is possible, the brush should be avoided so that the goal can be reached with no loss of time.
The brush makes it more difficult to spot foes, and it is home to the smaller wildlife and beasts that can prove troublesome, like foxes. a Thus, caution is the best advice to follow when moving through the brush.
Unlike the grassland and the brush with the occasional, or small group of trees, a forest like the Deep Forest or Spiritwood covers big areas with dense growth of tall trees. While beautiful looking, it has its drawbacks. This density of the growth not only seriously hinders visibility, but also slows down the adventurer a lot. Travel through the wood therefore should be avoided, if possible, especially because of the dangers that lurk within.
Aggressive reapers like to camouflage themselves as harmless trees until striking. Mongbats, bears, wolves and headless also call the forest their home, and react aggressively towards intruders. One peaceful inhabitant is the deer, so supposed king of the forests.
Swamp areas like the Bloody Plains and Fens of the Dead are very dangerous. The muddy and soft ground slows down the adventurer seriously, while the muddy, contaminated water is infested with small vermin that can infect the traveler with the worst diseases and poisons, and can only be held back by wearing swamp boots. The deeper water pits are completely impassable.
As if that isn't bad enough, swamps are home to a number of dangerous wildlife and monsters. Alligators, swamp plants, insect swarms, slime, rotworms and corpsers are frightingly common around swamps. Thus avoid the swamp, if possible.
Travel in the desert of the Drylands is dangerous. While there is no lack of visibility (after all, there is next to no vegetation), the intense heat and lack of moisture in the air are a different reason for the adventurer being slowed down. Another problem is that the heat results in provisions being used up faster and mirages tend to confuse the traveler.
Tundra -such as the Northern Regions of the Serpent Isle- are areas close to the poles where the temperatures are always below freezing and which are covered with ice and snow. Visibility is a problem not because of vegetation, but because of the snow seeming to let everything melt together into one white mess. Besides being seriously slowed down, the adventurer has to invest into warm gear, or death in these cold areas is unavoidable.
There are a few dangers beside the cold as well. Polar bears do not tolerate intruders in their domain, ice hounds roam the empty plains, and wolves are found here, as well as various other animals that have adapted to the cold.
Tundra made its first appearance in Ultima VI.
Hills and Mountains
Hills and mountains are obstacles in itself. Hills merely slow down the adventurer, while mountains like the Serpent's Spine have to be climbed with a grapple, which is both time-consuming and dangerous. The highest peaks are totally impassable. As one might expect, visibility is extremely low in the mountains.
While most obstacles are passable by some alternate form of transportation, few of these can withstand the primal-hot fury of lava. Responsible for the creation of new land masses as well as the destruction of whole areas and man-made constructions, lava is most often encountered underground, but is sometimes seen on the surface near active volcanoes. A rare few structures are built using large lava lakes as a measure of added defense, such as the Castle of Fire during the reign of Exodus, and the great lava lake surrounding Daemon's Crag in Pagan.
A few rare magic items have been created to bypass lava, such as the Dragonskin Boots and Leather Vest of Flameproof found in the Stygian Abyss, but beware of imitations! In Savage Empire, a modern fire extinguisher could be used to temporarily cool small sections of lava in order to quickly walk over them.
Lava was first seen in Britannia soon after Exodus rose from the depths in Ultima III.
Terrain of the Sea
Coast and Shallow Water
The coast itself can be searched by foot. However, to actually move through the rivers, lakes and shallow costal waters, the adventurer has to organize a skiff or raft, since bigger ships can't enter these waters.
These coastal areas and shallow waters have dangers of their own. Giant crabs sometimes roam the beaches, while predatory fish and sharks make the waters dangerous. Trolls tend to wait at bridges over rivers.
Coastal and shallow waters were first distinguished from deeper waters in Ultima IV.
Only large, seaworthy vessels like the frigate can explore the ocean; other vessels can't survive the rough sea. Besides the danger of getting lost at sea, the biggest natural dangers are the whirlpools that can eat a ship whole.
Also, the ocean is home to several nasty creatures of the deep. Besides sharks, sea serpents, the Kraken and seahorses will attack intruders, while the nixies have no problem with killing travelers. Also, the threat of pirates is always a given.
Water - No one in Ultima II knows how to swim except the sea monsters. You can only cross water with a frigate, or pass over it by air.
Grass - No problems moving on grass, but don't expect it to save you from starvation. Your character is assumed to be humanoid, not bovine.
Swamp - You'll have trouble making it through a swamp if you're low on hit points. You lose points with every step.
Forest -Sometimes there are more monsters in forests, hiding behind trees. But they're pretty trees and give nice shade.
Mountains - The mountains are insurmountable even for the most hardy adventurer.
GRASS: The smoothest and easiest to travel on, the lush grass of Britannia serves to fatten its herds. One may be pass here with any impediment.
BRUSH: Low scrub growth and bushes will hinder thy progress, permitting thy party to move but at three quarters if thy normal speed. Fine tinder for campfires may be found at the base of larger scrubs.
FOREST: The going is slow through dense woods, with thy speed cut fully in half. The oak so dearly loved by the Druids predominates here, along with healthy growths of Ash and Beech. There is quite a lack of visibility in the forest regions.
HILLS: Hilly terrain, much favored by those who raise sheep, will slow thee down considerable, so much so that none but the sure-footed mountain goat can move at more than a snail's pace.
MARSH: The marshes and fens are particularly treacherous and should be avoided at all costs. While progress is only slowed to half one's normal pace by the muck underfoot, the marshes give off poisonous gases which can severely harm members of the party.
MOUNTAINS: Mountaineering is not a well-known skill in Britannia, so the mountains are closed to the normal traveler. There is also a lack of visibility over the mountains.