Actually Railroading can and is performed by players as well on the DM. This came up a year or two ago along the lines of a player declaring they find a shotgun behind a bar. Not roll for to see if anythings there, or the DM saying anything. The player just poofed it into existence. That is a player railroading the DM.
And I've seen far far far far too much of where one player forces an action on another players character.
What I've seen all too often is that its the IC fanatics and storygamers that cause the most trouble with these stunts.
What is IC fanatics? I mean what is IC, I do not recognize this shortcut.
But generally I'd still disagree. Railroad demand certain rails. It generally is term assuming GM has well long term plans and will push or trick players into following strict narrative for long time, at least adventure. So I'd not call fudging one random encounter to be one.
And storygames are different batch. First they generally try to avoid specific rails (while enforcing genre rails, which make doing un-genre stuff generally not important), but yes they ditch rigid setting and give players some elements of power over world itself. Alas you still have to roll well for some weird move to get this shotgun, you cannot just easily wish it, and it has to be a game that assume finding weapons wherever is something we're doing (like some postapocalyptic shooter game or whatever). Simmilarily if mechanics allow you to force other players to do something (which tbh is way much older problem of using social skills in PVP mode), it's still matter of chance, and roll. And quite commonly other players have their own moves to use to force you to do something. So no, with dispersion of narrative power, and such weird stunts being based on rolls, I'd say it's hard to call it railroad. Railroad assumes result is known before you start playing.
(Especially if you botch roll that would give you this shotgun, then mechanics usually demands something bad happen - rolls in those games usually demands something good or bad happens, never mere miss.)
Then alas if you play game derived from PBTA and you clutch to rigid setting you're playing it wrong.
I'd rather say "player railroading" is something that can happen in what's calling OP-style, usually on more traditional games, well nowadays mostly on 5e, where one player hijinks games, and sort of forces GM and other to tag along because he has this plan of character arc, 20-pages backstory, and he needs to fullfill those, if there is to be fun. There is see danger of player-centric equivalent of GM-railroading.
Now for the rare bird who nonetheless does feel railroaded and frustrated by this, there's another surprise. That your annoyance is not justified by the facts because your choice at this fork in the road actually does matter. For it is some NPC that's doing it. The NPC is the prisoner of a dragon, and this is the NPC's way of getting heroes to help. And each time the NPC has to transport the PCs back to the fork in the road, more of that NPC's energy is sapped. And the less energy the NPC has to aid the PCs in confronting the dragon. The longer it takes you to recognize the low road is the solution, the slower you are to adapt, the more reluctant you are to embrace adventure, in other words, the poorer your choices, the less advantaged you are. Isn't that exactly what we expect out of player agency?
I can see it being frustrating. TBH I'd probably add caveat that after dunno 3d6 transporting of players back, prisoner faints from expending to much mana, and is eaten by dragon, and dragon later become powerful enough to terrorise whole country, while players simply move on.
My takeaways here.
Reserve judgment regarding railroading. Reserve judgement by a lot.
Railroading isn't railroading when it's an NPC doing. All the railroading GM needs to do to make his or her beautiful plot kosher is hand over the puppeteer strings to an NPC.
NPC villain masterminds, to the degree that they are effective, can rob players of agency. There is no sacred right to agency, other than the existentialist choice to decide what sort of prisoner you will be. Everything else you've got to earn.
That I generally agree, though of course numbers of players hating such solutions is quite high.
A little of on the fly world creation goes a long way, so when I am in the middle of things I prefer to let the randomness to decide. Bias is easy to slip into (either for or against players, conscious or subconscious) and I am struggling to not only be fair, but also keep the appearance of fairness. One of my offers to the players for their trust and our shared suspended disbelief is to prepare beforehand and 'let it ride' (gambling euphemism) during as best as I can.
I must say I simply enjoy certain dose of randomness as GM, though I'm unfortunately not that good in executing it myself
Illusionism is giving players the illusion of choice while negating it in practice. So yes it is closer to what you are talking about. Moving the adventure location to the PC location is illusionism. It's only railroading if the players are trying to avoid the adventure. Just-in-time procedural content generation is 'improv' but is not 'illusionism', especially if player choice determines eg which table gets rolled on (hill encounters vs forest encounters, say).
IME running a sandbox there is inevitably a mix of pre-created and just-in-time content generation, this doesn't make the sandbox a railroad or illusionist.
Yes. I think it's good take. I mean let's say you want player meet team of assassins send for them - they can move all around map, and will catch to them eventually, no matter where player move (though of course environment may change how encounter will look like, so still choice of players to move north instead south can matter.)
Thinking about it, I do tend to agree with the OP that using published material can be good practice to avoid illusionism. I like to buy a f-ton of short published adventures and seed them around my sandbox. The players are typically aware of at least several possibilities for adventure at any one time, and can decide where to go and what to do.
Though many published adventures have enough bad illusions all around that you need to tweak them to make game working anyway.