Maxperson
Morkus from Orkus
You're conflating deciding the outcome with deciding what can be plausible. The DM has no ability to decide what can be plausible, only which outcome he decides upon.Everyone may have an opinion on the plausibility of any development in play... but since the GM is the one deciding what the development will be, it would very much seem that they can determine what is plausible.
Players may disagree... but that may or may not matter, depending on if the GM is open to discuss and potentially revise things.
You're making the same mistake as @Hussar and conflating highly unlikely, but possible with plausible. Plausible is what is reasonable/probable. It's highly improbable that a merchant is going to show absolutely no signs of leaving, and then vanish overnight. Possible, but not plausible.Maybe, maybe not. Can a plausible reason be crafted to explain all this? Yeah, probably. Since there is no actual causality at play, the GM can make up whatever they want. That flexibility gives them a lot of leeway.
You can come up with a reason where it's possible, but there is no reason that will make the highly unlikely plausible.
That's not what I was talking about, though. I was talking about taking the Realms and any DM being able to extend the setting logic(as implausible as some of it may be) and use that setting logic to run games that are in line with that setting logic.The Forgotten Realms is an implausible mess! It's a bad example to go to for plausibility.