Internal consistency
Also said as World logic, Consistent rules
The world obeys its own rules every time, whatever those rules are. A world can be as strange as you like, as long as it stays strange in the same way.
Players rely on the rules to plan. Break one for the sake of a scene and they lose more than the scene, since they stop trusting everything else you have told them.
Say it
“The bell always rings two seconds before the flood. No exceptions, not even for the boss. If we want a surprise, we build it out of that rule, by making the player unable to hear the bell.”
Where you’ve seen it
The solar system in Outer Wilds runs the same way on every 22-minute loop: the sand moves between the twin planets on the same schedule, and Brittle Hollow breaks up the same way. Because it is so consistent, you can plan around it.
Not to be confused with realism
Realism is matching our world. Consistency is matching your own. Gravity can reverse every Tuesday, provided it really does so on every Tuesday.