[kbs666]

As Acenoid says if the dialogue is specific to a particular scene I put it in the scene. If its just dialogue a person might say anywhere that NPC might say anywhere that NPC might be encountered I put the snippet in the NPC topic.

One of the things people tend to struggle with as they start using RW is not being tied to the default format of the topic categories. You can add snippets anywhere you need them or entire sections to a topic if you need them, if you do want to add a snippet or section as a default to every topic in a category the best way to do that is to create a copy of the category you want to modify, modify that copy as you wish and then enter your data in that copy.