I was looking at the preview page from the DMG on adventure design, on this website -
The new D&D core books feature nearly 400 spells and over 500 monsters, but disappointingly few new ideas - and to me it seemed a bit contradictory.
Here's what I mean:
Follow these steps to create an adventure: . . .
Step 3. Plan Encounters. How does the adventure play out? Determine the encounters or events that take the characters from the beginning of the adventure to the end.
Step 4. Bring It to an End. How do you expect the adventure will end? Think about possible endings as well as rewards for the characters. . . . .
[W]hile it's worthwhile to compare an adventure to these other forms of storytelling [novels, movies, comics, TV], remember that an adventure isn't a complete story until you play. . . . the events of the story shouldn't be pre-determined: the actions of the players' characters have to matter. For example, if a major villain shows up before the end of the adventure, the adventure should allow for the possibility that the heroes defeat that villain. Otherwise, players can feel as if they've been railroaded - set onto a course that has only one destination, no matter how hard they try to change it.
You might find it helpful to think about an adventure not as a narrative that arcs from beginning to end with little chance for deviation, but more in terms of situations that you are presenting to the characters. The adventure unfolds organically from the players' responses to the situations you present.
The stuff about not railroading, and about presenting
situations (to the players, really, even though they say "characters"), seems at odds with the advice to plan how the adventure will play out and end, and what the encounters/events will be that take the characters from the beginning to the end.