Basically, Tortured Hearts is conversation-driven. This is the prime mover to advance in the game. There's a lot of text to read, the number of words in conversations is about 512,000, just companion banter is approximately 150 k. Depending on what you say, there may be different outcomes that can advance a quest, gain a friend, a story option or start a fight. There are over 400 ability and skill checks throughout the game, so... good luck for them. Hint: equipment and buffs help...
Companion interaction is also managed via conversation. They will frequently react when you enter an important location or advance a particular quest. Sometimes they will or will not like what you're doing and it's possible to even make them angry. NPCs are no expections. It is advisable to save before you start a new conversation, although the plotline can't be screwed at all. Sometimes you talk to yourself...
Due to the non-linear nature of the game, some important NPCs will have new things to say after a while, even if you think the area has dried out, so to say. If you quit a conversation, it's strongly advisable to check if the guy in question has something else to say. If a character has a one-liner only, there's a 99% chance that he won't say anything more. In order to keep the game beatable, plot critical characters cannot be slain.
CONVERSATION