Can a session of an RPG take place on a train and not be a railroad? Yes, groans all around.

If the transportation is on rails and the action happens on the transportation, how do you handle the game play and not make it a “railroad”?

There’s a scenario like “Murder On the Orient Express”, or a train robbery in the old west, or many others.

Similarly, if the players are on a ship at sea or a vessel in space, their ability to go when and where they want is limited.

As with all sandbox style play, the players should have a choice of whether or not they get on the thing. They can choose to remain on board for the entire duration of their stated journey, or exit at any scheduled or unscheduled stop, or jump off mid-voyage. Although jumping off a moving train is probably safer than jumping off a ship in the middle of the ocean or a star ship between systems. Unless there is some device or plot element to enable near guaranteed survival.

Players should be free to follow or not follow any clues to past, present, or future adventures. They should be free to attempt to go to any location on the train, ship, or other vessel, like the engine, or engine room.

As with real life, if I was on a train, and wanted to go to the engine, I could try to do it. I might slip and fall to my death, but I can try it. So if a player says they want to go to the engine room of the ocean liner, let them try it. They might meet a surly crew member, or end up in the brig, or they just might make it work.

With any sandbox style of play, the answer from the GM should not be “No.”, but “Let’s see what happens!”

Be ready for the appropriate random rolls for skills, abilities, morale, reactions, or combat. If they can turn invisible and/or walk through walls, it might be a trivial task. However, if they can’t do those things, it could be an epic way for a character to “retire” ….