on rails

on rails

1. (video games) Rail-based.
2. (video games, of a character or object) Constrained to travel along a preset fixed path.
   • 2012 November 10, Scott Manley, 0:18 from the start, in What does it Take To Deorbit A Moon In Kerbal Space Program‎, archived from the original on 26 September 2022:

     So, first of all, let's clear it out of the way: it is not possible to deorbit any of the moons in the game. They are all on rails, and nothing you can do will adjust their orbit in any way whatsoever.

3. Used other than figuratively or idiomatically: see on,‎ rails.

• Lairson, Larison, Nailors