The game will never be played the same way. The combinations of events, map tiles, items and monsters makes every session unique. There is no predefined map layout for the chosen scenario and chapter effects can be used as an additional strategic component of the game.
Game is really hard - the immersion is created with desperate situations, not only with chapters. Each scenario has its own events that are shuffled into core ones, so each time you will get a different flavor through resolving event cards.