The main title of the Naturvetarna series translates roughly to "those who know about nature", each individual entry covering a Swedish biome. For instance, the Skogen ("The Forest") box deals with species of plants, animals, mushrooms and lichen that can be found in various Swedish forests. The game consists of a deck of 82 cards, with two cards to a species. One of these has an illustration on the front, the other a few sentences written in the first person listing characteristic traits or related facts; both have the name of the species on the back. Several ways to use the cards are suggested, such as employing them in group exercises (e.g. sorting cards by categories or shared traits) or for a scoreless solo matching game. When played competitively, the rules suggest dividing an arbitrary number of participants (like a class of pupils) into two teams, potentially with a moderator (like a teacher) to read out clues from the text cards. The teams then try to collect pairs of cards either by identifying the species on a given picture card, gaining an additional point if they don't need any clues to do so, or by selecting the right picture card based on the clues from the corresponding text card. In addition to Skogen, the series includes the entries Insjön (The Lake), Ängen (The Meadow), Havet (The Sea), Fjället (The Fell), and Staden (The City).