Chapter 1 - Mechanics of Speech
In Glass, conversation consists, not of static things to say about specific topics, but of moves from one conversation topic to another.
Any pair of ideas can have some specific dialogue associated with it, so that when we ask about marriage, we get a different answer if we are coming to the subject from the masquerade ball than if we are coming to it from the king's health (for instance). So we will define some conversation topics, called "subjects", and also provide tables of what may be said in moving from one subject to the next.
The player is allowed to try to move from any subject to any other, but non-player characters -- the other people in the room -- will only make conversational connections that "make sense": subjects that suggest related subjects. So we define a suggestion relation to connect one subject to others.
Non-player characters are also trying to reach specific conversation outcomes, so they will seek the best path from the current subject to their goal subject, and keep the conversation moving in that direction. Only the player's intervention (or a change of goal) will knock this off course.]