It's a good idea to provide some variety in a character's default responses, because it seems that in every real game session, the player will at some point spend a while peppering an NPC with questions on every topic that comes to mind. Usually, the player will think of many things that the author didn't anticipate. The more things the author covers, the better, but it's unrealistic to think that an author can reasonably anticipate every topic, or even most topics, that players will think of. So, we'll have a whole bunch of ASK, ASK, ASK commands all at once, and much of the time we'll get a bunch of default responses in a row. It gets tedious in these cases when the NPC repeats the same default response over and over.
A simple but effective trick is to provide three or four random variations on "I don't know that," customized for the character. This makes the NPC seem less like a totally predictable robot, and it can also be a convenient place to flesh out the character a bit. An easy way to do this is to add ShuffledEventList to the superclass list of the default topic entry, and provide a eventList list with the various random responses. For example:
+ DefaultAskTellTopic, ShuffledEventList
['Bob mutters something unintelligible and keeps fiddling with
the radio. ',
'Bob looks up from the radio for a second, but then goes back
to adjusting the knobs. ',
'Bob just keeps adjusting the radio, completely ignoring you. ']
It's important to be rather generic in default responses; in particular, it's a bad idea to suggest that the NPC doesn't know about the topic. From the author's perspective, it's easy to make the mistake of thinking "this is a default response, so it'll only be used for topics that are completely off in left field." Wrong! Sometimes the player will indeed ask about completely random stuff, but in *most* cases, the player is only asking because they think it's a reasonable thing to ask about. Defaults that say things like "I don't know anything about that" or "What a crazy thing to ask about" or "You must be stupid if you think I know about that!" can make a game look poorly implemented, because these will inevitably be shown in response to questions that the NPC really ought to know about:
>ask bob about his mother
"I don't know anything about that!" *.
>ask bob about his father
"You'd have to be a moron to think I'd know about that!"
It's better to use responses that suggest that the NPC is uninterested, or is hostile, or is preoccupied with something else, or doesn't understand the question, or something else appropriate to the character. If you can manage to make the response about the *character*, rather than the topic, it'll reduce the chances that the response is jarringly illogical.
DefaultTopic : TopicEntry