FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Conversations with Nonplayer Characters
From the original Adventure onward, adventure game designers have faced the problem of how to create realistic NPCs. Computer role-playing game (CRPG) designers must address this problem, too, but in most CRPGs, an NPC's conversation is defined by the character's role: blacksmith, healer, tavern keeper, and so on. The
player doesn't expect to be able to discuss arms and armor with a tavern keeper (although the games might be more interesting and certainly less formulaic if he could). But because adventure games are interactive stories, players expect the characters in them to be more like humans and less mechanical.
A good many games try to sidestep the problem entirely by setting the game in worlds with extremely few, if any, people. This certainly creates a mysterious atmosphere, but it suits only a limited range of stories. Imagine how Rick's bar in Casablanca would feel if it weren't full of people drinking and gambling. A world with no people seems artificial and sterile.
A few early text-based games tried to implement parsers that could understand limited English sentences as typed by the player, but these seldom succeeded. NPCs either said, "I don't understand that," or gave absurd answers when the player asked a perfectly reasonable question; this left the impression that the NPCs were drugged or mentally ill.
In the end, most adventure game designers gave up on trying to create the impression that the player could talk to anyone about anything and devised the scripted conversation, a mechanism that became the de facto standard for both adventure games and CRPGs. Chapter 7 discussed scripted conversations in detail.