Today I read about the Romulan home star system and it looks like it might be impossible for such a star system to exist.
Memory Alpha describes Remus:
Remus was tidally locked, with one hemisphere always facing its primary while the other always faced away from it. The civilization of the Remans was located on the night side.
Remus is farther from their star than Romulus. Romulus rotates many times during a single orbit of their star while Remus is tidally locked and rotates once per orbit of their star.
If a planet orbits even deeper in the gravity well of their star than Remus it should be even more likely to be tidally locked than plants further out.
Could tidal interactions with neighboring planets and/or its moons prevent a planet from becoming tidally locked while being unable to prevent planets further out from being tidally locked?