The invention provides a role-playing game environment wherein the nature of various NPCs within the game may be varied over time within the game. The goals of various NPCs within the game may be dynamically and automatically changed within the game. At certain in-game time periods, the game server may dynamically assign one or more new goals for some or all of the NPCs based on the current status of each NPC. When a player later interacts with a given NPC assist (or impede) that NPC in reaching its currently assigned goal, the method may dynamically determine a steps that the player's avatar may perform to assist (or impede) the goal. Thus, players cannot predict what will happen when they move through the game and reach a location at which they can interact with a given NPC, making the game-playing experience ever fresh and challenging.