Jotunheim is not a place for the faint of heart. It is the land of the Frost Giants, and that makes it a very dangerous place to begin with. Jotuns are only one of its many hazards, though. It is populated by a variety of deadly monsters, and it is in many respects a frigid wasteland where only the hardiest survive for long. A journey to Jotunheim is a momentous undertaking for a god. For a mortal, it is the mission of a fool.
Jotunheim is one of the largest of the Nine Worlds. It stretches out for many, many miles, encompassing enough land to span all the nations of Midgard and more. It is eternally winter there, and the whole of the realm is made up of snow-capped mountains, glaciers, and tundra. Jotunheim does experience seasonal change, but summer (such as it is) lasts only for a month and is characterized by temperatures only slightly above freezing. Autumn lasts for about a week — just enough time to alert the denizens to the fact that winter is returning. Spring tends to be longer — usually two months — but it features alternating periods of warming and sudden storms that plunge temperatures back down.
The northern and western edges of the realm are studded with enormous mountains that stretch up into the clouds. These forbidding peaks are home to the castles of the most powerful giant jarls. Huge glaciers run down the mountainsides like rivers of ice emptying out into the frozen tundra of the plains below.
Jotunheim is bordered on the east by a large sea that separates it from Asgard. While small communities of giants do live on the shore, there are no ports or cities providing access to or from the harsh land. The terrain between the tundra and the sea is marked by large rolling hills that are difficult to navigate in bad weather owing to the snow that lifts into the air during storms.
Jotunheim is the land of the Frost Giants, but they are not its sole inhabitants. A wide variety of monsters also populate the frozen realm. Generally speaking, any creature with the Cold Subtype can be found in Jotunheim. It also makes a good home for monsters with any mountain in their climate description, though keep in mind that the temperatures are universally cold so only monsters that can thrive under those conditions will be found here.
It’s important to note that everything in Jotunheim is big. It is a land populated by giants, and everything around them is giant as well. Many of the creatures on the random encounter tables have been adjusted in size to reflect this. As a general rule, if you want to use a creature that doesn’t appear on the charts, you should adjust its size up one level to reflect the gargantuan nature of the land of the Frost Giants. A Jotun’s dog is a big challenge for a mortal and can cause some trouble for a god owing simply to its size. Use your common sense since some of the creatures in the game are already meant to be “giants.” In general, though, bigger is definitely better.
This applies to everything about Jotunheim. The trees are like redwoods. The mountains are like Everest. Everything is expansive. A giant’s house is a mansion to a puny mortal or god. A giant’s castle is akin to a city by way of comparison. Don’t forget that the Jotuns are very worthy foes to the gods. Everything about Jotunheim is large and challenging and dangerous.