D&D 5E Moving out of an enemy creature's space

[Rya.Reisender]

Some creatures have the ability that they can stop on a enemy creature's space (e.g. Water Elementals).

Since for other creatures the rule is that they cannot move through a creature's space, I was wondering if those creatures cannot move at all when such a creature is on top of them or if moving out of a creature's space is allowed, just not entering it? How would you rule that?

 

[Distracted DM]

You can move out of their space, yeah.

 

[Rya.Reisender]

Thanks! I think I'll allow it as long as the target space is not occupied (we play on a grid).

 

[Hriston]

Yes, moving out is allowed. Conceptually, moving through a space is entering that space, so entering a space with difficult terrain costs two spaces of speed whereas entering a normal space only costs one.