The issue is when the DM forces what he wants to happen, ignoring what should happen. You've said you engage in railroading. On a railroad the players' actions can't matter, since you are going to force what you want no matter what.
Sure if you use 'railroad' as "anything the DM does the players don't like".
In nearly all cases the bad or worse players will defeat themselves....so no 'railroading' is needed....they will stay on their own Track of Doom.
So long as you keep saying "the players" you can't be correct here. Players in general don't believe that they must succeed. Some rare few probably do, but as a whole "the players" don't.
This is not what I experience. If the players are not thinking the must always succeed, then why to they complain so much?
Anyway, the demons still kept coming through and I'd periodically roll to see how well other heroes were handling things. The problem became steadily worse and rumors of things would reach Amn. I wasn't going to force the demons onto the PCs/players, but the issue still happened in the background, adding to the depth of the world. They understood things were happening from beyond their control and influence.
Right, this is a perfect example of what I said: Because the players wished something, you as the DM altered the game reality to make it so. The players say "we don't like the demon stuff" and the DM says "yes, players, the demons go away."
I really don't get the point of why you high light the 'demon story' in the back ground. What is the point if it will never effect the game? Sure as part of your DM Novel you can say what is happening far away from the game....but what is the point?
No. If they do something like that you have two choices. Improvise fairly, not as a counter to what they do, but what the organization would fairly have done. Pause to think ahead at what defenses they would have in place and then let the players begin their attempt. Or pause the game and let them know you need to prep for this since you weren't expecting it. Then they can encounter the defenses and plan ways around them.
Well, one of the Tag Line of my game is that it's Unfair. Maybe players should pay more attention to words.
But it's not like a DM can be fair when they outclass their players. I can think of tons of things...but the bad players struggle with even one. One from just a few weeks ago: The players struggle to get into the vault...and find it only has a small amount of loot. Unhappy the players whine and cry about their actions not mattering. And to this day if it get brought up they will whine and cry about it. Of course the simple truth is : there was a hidden vault inside the vault. But the players can't even conceive of that idea. So they never checked....just whined and complained.
The important part is not to force what you want(railroading) or to just come up with ways to shut down their ideas as they come up(adversarial DMing).
That sound fine in general.
Well, except my game is a full railroad game....
Or not, because it doesn't work that way.
I think it does. I'll have to check to be sure......but this seems like a good answer to "Why do players so LOVE to do random things to "surprise" the DM?"
Just let them know that the guards don't fall asleep. My players wouldn't do that. They'd leave and buy potions of invisibility or passwall scrolls to bypass the guards. You know, planning to overcome the defenses.
I'm not a Buddy DM that is on the players side and a fan of the players and give them endless OOC help.
On DC....well I have another thing that hundreds of players and DMs do...and yet "Nobody" here has ever even heard a rumor of it:
So the Buddy DM says the DC is 15.
Then the players pick the character with the right skill/ability or whatever, with the highest plus and make sure to add the mundane and magic or expertise or advantage or whatever needed to make sure they get that 15. Then they roll and get higher then that 15 needed...amazingly.