Occasionally writers are advised to avoid using prologues. I want to bring this up because, honestly, I do not understand why prologues are thought to be a bad idea!
In my opinion, a good prologue can provide valuable information that a reader might not find included in the main story - for instance, something which happened long before the events of the story begin, but which is a principal cause of the current story. A prologue might serve as in invitation into the story or a sampling of what is to come, or a frame story which adds another dimension to the novel. And as a reader, I actually enjoy reading an interesting prologue.
So tell me: what is you opinion of prologues? Do you ever include them? And as a reader, do you like them, or do they annoy you?