Entering a biome, the player finds themselves in a room with available adventures. It's possible that no adventures are available, in which case the player can create a new one.
The available adventures are adventures that were previously opened by other players who were unable to complete them. If a hero perishes in adventure (permanent death), they lose all their equipped items and potential rewards. In case of a loss (the loss of life chance), the hero only loses potential rewards. As a result, the available adventures may contain rewards left behind by previous players. If a new player successfully completes a given adventure, they will receive not only their own rewards but also the additional rewards left by previous players.
Each adventure is generated from scratch every time, with rooms appearing randomly. It's impossible to predict the number of rooms and the specific content within the adventure.