The guests, who are integral to the gameplay, are treated as separate entities which can each have particular characteristics and be tracked by the player around the park. The game keeps track of how much money they have, what they are carrying, their thoughts, and what their current needs are (thirst, hunger, etc.). Each guest also has some unique features such as their preferred ride intensity, and their nausea tolerance. Some scenarios are even biased towards a specific guest demographic and require the player to take this into account in designing the park. In "RollerCoaster Tycoon 3", the player can create their own guest groups to visit their parks.