How is the portion of the frightened condition meant to be interpreted:
The creature can’t willingly move closer to the source of its fear.
More specifically, what is meant by "move closer"?
Here are a few options I've come up with which may include some insights into the answer:
- The shortest linear path (ignoring obstacles) cannot be decreased
- This would mean I could not approach a wall when the source of fear (let's say a creature) is on the other side even if it increases the distance it would have to travel to get to me (say around a winding corridor)
- The distance that would need to be travelled to reach the source cannot be decreased
- This has the opposite effect of option 1. I could move closer to the wall, but not into the winding corridor that the creature is approaching from.
- The travel time to reach the source of fear cannot be decreased.
- This is relevant for cases such as difficult terrain, variable movement speeds, planar travel (would portals factor in?), and other such factors.
I'm sure there are other interpretations that I haven't come up that may be more in line with the rules.
Best Answer
Closer is physically closer
I think you may be reading more into this than necessary, but the language of can't move closer is really as simple as can not get physically closer. If at any point in the target's movement they try to be physically closer to the source of their fear, they can not continue and must choose a new path.
That leaves #1 as the answer to your question.
You may move around, you may take a path that is the long way to the caster, but as soon as that path puts the target in a position that is closer than where they were when first affected, they must stop and go somewhere else.
Scary monsters!
Remember, you are frightened! You do not want to get anywhere physically closer to your fear. It's all about proximity, that's all your thinking about. It's not about time to travel to get to them, it's about being close to them. And that's exactly where you don't want to be. You are not thinking logically, you are reacting irrationally to your fear.
Fear is a funny thing
The role-playing goal here is to play scared. If you've got an idea that plays that, and aren't trying to get close enough for a spell or attack, then by all means describe it to the DM. Rule of Cool is cool.