All too often I see GMs (or DMs or storytellers or whatever your role playing game of choice uses) talk about players “abandoning the “main” story. There are also many posts where GMs also talk about how they know their campaign will start and end. This is not good.
For some people, their “railroading sense” will tingle, but I’m not diving in to that particular issue here. Rather, I want to get GMs to start better campaign preparations to empower player agency and have a campaign the group contributes to.
So as a game master, your job isn’t to write stories. You’re not an author, screenwriter, or playwright when you’re working on your game’s campaign. Your job is to write scenarios.
A scenario will be an event or series of events that your player characters will have to react to or make a decision (and sometimes both). Scenarios present obstacles and challenges to overcome. What they don’t have are conclusions.
This doesn’t mean there are no consequences, it simply means the consequences haven’t been decided because the actions and resolutions haven’t been decided. You don’t write the actions, and you don’t pre-plan the resolutions. Your players (and you through your NPCs and setting) will be ones who determine the actions, and from those actions will be the consequences (and remember, consequences aren’t always bad, they can be good or completely irrelevant at the conclusion of the scenario).
Page through some published modules and adventures (the good ones, mind you) and you’ll see at no point do they lay out what the player character party will do. They instead lay down a foundation for what the player character party might interact with. That’s scenario.
Take the set up for Curse of Strahd from D&D 5e. The opening premise is that the party is brought to Barovia and can’t escape because the lord, Strahd, won’t allow it. It is up to the PCs to decide what that means. Maybe they plan to confront the dark lord, maybe they think they can appeal to him and earn a favor, maybe they like Barovia, or maybe they just haven’t made up their minds. How the players decide to proceed is what will write the story for your Curse of Strahd adventure.
So as GMs, start work on writing engaging scenarios, events, and decision points, and then set your players loose to write the story.
The main story of your campaign, that you’re playing with your group of players, is the story of the player characters. Every thing else you’ve (or others when using published campaigns) is just background and setting. Learn to let go of the narrative reins and work with your players. Your game stories will be richer for it, oh, and you’ll probably be less likely to inadvertanty railroad your players.