Besieger is a real-time strategy game in which players fight as Cimmerian or Viking warriors. The game follows the story of Konin, the king of Cimmeria, during phase in ancient history when the Cimmerians are in a war with the Vikings. In this game, players are tasked to construct castles and lay siege on opponents.
There are 12 levels in which players control up to 50 types of units and construct 40 building types. Users can play in single-player campaign mode or multiplayer modes. In multiplayer mode, players can choose from a variety of gameplay types, including capture the flag, king of the hill, deathmatch, free for all, and cooperative. Aside from the human Vikings and Cimmerians, players also encounter and fight mythical werebears, ogres, and centaurs, among other non-human races.
Besieger allows players to build flying vehicles and use weapons such as battering rams in order to destroy the protective citadel walls of enemy forces. Conquered enemy buildings and weaponry may be acquired by victors. Counterattack strategies may also be employed, such as gathering troops in citadels. Players are given resources with which to construct buildings and train units. The game features 3D graphics. Battles are fought in photorealistic settings, such as deserts, mountains, and forests.