The previous post in this series explained how to get Graphics Magician images to display from Applesoft. Now, I'd like to go over the structure of the program listed in Write your Own Adventure Programs. The bulk of the program listing consists of the game data including objects, room descriptions, verbs and state flags. Most of the remaining code is comprised of a series of conditions that check how the player's actions affect the objects in the game world.
Haunted House used a simple, two-word input parser: VERB NOUN. But I wanted this new game to simplify the number of verb choices in the same way the LucasArts adventures streamlined the interface of Sierra-style adventure games. The player will be limited to around a dozen verbs that are entered with a single keystroke.