Quote Originally Posted by Quertus View Post
Well, you've certainly presented me with something challenging to discuss.

Let me create what I think is an easier to discuss parallel:

GM: Bob, the friendly guard is at his post, and won't let you pass. What do you do?

Player: I kill him.

GM: you can't - I already ran him as alive tomorrow with my other group.

It doesn't matter the reason, if the GM is ignoring game physics or facts to force or prevent an outcome, it's railroading.

Now, if you get player buy-in / Participationism, you shouldn't reach that point, and it's just a linear adventure, or a... I'm not sure what to call what you've described. An adventure with linear components, perhaps?

But any time you reach the point where you are denying the players the agency to have the PCs take actions, or to have those actions have the logical consequences that they would through following game physics, then you are railroading.
The point is that the DM has the absolute right to establish setting facts, even surpassing the game rules. Now there's a sliding scale--at the level you countered with, sure. The right thing to do there is to do a timeline split and rejoin/canonicalize later (after the campaign). That was not the case for my groups, because they were separated by thousands of miles without any way of transport.

On the other hand, there's a well-established use of background elements. For Group 2, the Cataclysm was a background element, along with a war between Order and Chaos. Their characters had no way of knowing it was going to happen--no one did until it did happen (because of the effects of Group 1's actions).

So setting up backdrops that the party have no way of responding to is not railroading. Group 2's whole final scenario was them (a group of level 4-5 4e D&D characters), an army of "Order" and an army of "Chaos". The Chaos army was led by the literal physical incarnation of Change and Chaos itself, one of the initial beings who created everything. Effectively the heart of the Abyss made flesh. A being against whom even the gods were outmatched. There was not way for them to win this war. But they weren't supposed to win--that wasn't their job. Their job, and their meaningful choices, were about taking actions at the fringes of this war. Saving that person (or group), not this other person or group. Joining Chaos or not. Fighting to the bitter end or fleeing. As it turned out, about halfway through the session was when Group 1 initiated the Cataclysm (by doing something very predictable, but very stupid. Except it worked, so it wasn't stupid.) This locked both sides of the war down enough for a desperate plan (still in the background) to accept change into the natural order and end the war, at the cost of all the gods' lives. Group 2's last session then ended with them gathering survivors and rebuilding. They could have just fled, they could have chosen to take command (since the higher-ups were all killed), or many other outcomes. The war? The Cataclysm? Those are background elements that happen according to the needs of the story. And using them is not railroading. Agency does not have to be total to be agency--it's not a denial of agency to say that you can't do something impossible. And impossible is set by the narrative, not the rules (unless we choose to delegate).

The DM can introduce these background elements without warning the players and getting explicit buy-in--it's part of their job. The players don't get to look behind the screen and judge "did you set that up in advance?" That's the social contract of trust. Without trust, the whole thing falls apart. No set of rules can simulate the world and make it believable, not even in the slightest. No printed module can even slightly begin to give enough information to do an adequate job of this without railroading the players hard, because they can't predict all the possibilities.