As agents and publishers request samples (first 3 chapters or 50 pages), I'm concerned that they may be looking for a sample that grabs the reader immediately leading right away into the adventure of the book. However, I want to take time to establish my characters and the places where they live first before moving on to the more exciting parts of the story. Based on the experience of writers on this forum that have dealt with agents and publishers, to what extent are they either looking for or pushing for this type of thing? Is there a bias now to starting books in media res? How much build-up do they generally allow? I haven't submitted my work to anyone yet, but I have this nagging feeling that there is a bias to starting a story in media res these days even if that's not the way I want to tell my story.