Interactive Narrative Planning in The Best Laid Plans

The Best Laid Plans is an interactive narrative video game that uses cognitive-inspired fast planning techniques to generate stories with conflict during play. Players alternate between acting out a plan and seeing that plan thwarted by non-player characters. The Glaive narrative planner combines causal-link-based computational models of narrative with the speed of fast heuristic search techniques to adapt the story each time the player attempts a new plan. About The Best Laid Plans The Best Laid Plans is an interactive narrative point-andclick adventure game. Players take on the role of a hapless goblin minion in service to the skeletal Dark Overlord. The goblin is tasked with visiting the local village to retrieve a bottle of hair tonic and return with it to the Overlord’s tower. Play alternates between two modes. In Make Your Plan mode, the player acts out a sequence of actions to obtain the hair tonic and return to the tower. Non-player characters (NPCs) do not act in this mode, allowing the player to explore many possible ways of completing the mission. Once the player has acted out a complete plan to fetch the hair tonic, play changes to Watch Your Story Unfold mode. Now the player watches the goblin execute the plan, but in this mode the non-player characters will act to thwart the goblin. When the player’s plan is thwarted, play returns to Make Your Plan mode and prompts the player for a new plan. The game alternates between these modes until the goblin successfully reaches the tower with the hair tonic in hand. For example, in Make Your Plan mode the player acts out a simple plan to walk to the village, purchase the hair tonic from the potion shop, and walk home. Then, during Watch Your Story Unfold mode as the goblin is walking home, a bandit blocks his path, kills the goblin, and takes the hair tonic. Play returns to Make Your Plan mode at the moment before the goblin’s death, and the player must now find a way around the bandit. The player decides to return to the village, steal a weapon from the weapons merchant, and use it to fight his way past the bandit. But as the player is watching this new plan unfold, after stealing the weapon, the angry Copyright c © 2015, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved. town guard attacks the goblin for robbing the weapons merchant. Play returns to Make Your Plan mode, and the goblin must now find a way around the town guard. And so on. The Best Laid Plans is a small but non-trivial virtual environment containing 9 characters, 15 locations, and 17 items. Agents can take 10 different kinds of actions and cast four kinds of spells. The scope of this environment was designed to allow players to complete a game in about 15 minutes.