How wide of an area are characters dispersed when a Rope Trick spell ends?

Per the spell description:

Anything inside the extradimensional space drops out when the spell ends.

and

The space can hold as many as eight Medium or smaller creatures.

Given that a medium sized creature occupies a 5ft square, that would mean there is at least 200 sq ft of extradimentional space.

If I wanted to lay a trap below where someone cast Rope Trick, do I need to cover the full 200 sq feet? Or do they all fall on top of each other centered on where the rope went up?

In a more concrete example, could I just make a 10 sq ft spike trap centered on where the rope is (was if pulled up), or could character crowd the "edges" of the extradimentional space and fall outside of the pit?

For clarity: Since I'm basing this off a a question where the characters are only 7ft up, I'm not concerned with falling damage, nor will there be time to twist and turn during descent to avoid the trap.

• Note: a 5 ft square = 25 sq ft Dec 18, 2017 at 21:36
• on miss-conception to address a medium sized creature does NOT occupy a 5ft square, except in combat. And even then it doesn't fully take up that space it simply needs that much space to fight. This is represented in the fact that you can actually move through any space occupied by someone willing to let you pass Dec 18, 2017 at 21:36
• @MattVincent, thanks. It's Monday and brain not working yet. Dec 18, 2017 at 21:45

It's a DM call (like most things), but here is some precedence if desired:

• The Magnificent Mansion spell says: "When the spell ends, any creatures inside the extradimensional space are expelled into the open spaces nearest to the entrance".
• Banishment says: "the target reappears in the space it left or in the nearest unoccupied space if that space is occupied"
• Gate: "instantly transported to the other plane, appearing in the unoccupied space nearest to the portal."
• Maze: "When the spell ends, the target reappears in the space it left or, if that space is occupied, in the nearest unoccupied space."
• Blink: "you appear in the nearest unoccupied space (chosen at random if more than one space is equally near)"

All Fall Down

Rope tricks (PHB, 272) tell us about the entrance to the extradimensional space - along with what it looks like to peek out:

At the upper end of the rope, an invisible entrance opens...those inside can see out of it as if through a 3-foot-by-5-foot window centered on the rope.

Finally, when the spells it ends:

Anything inside the extradimensional space drops out

We know that you have to climb up the rope to access it, that the access window is about 3'x5' centered on the rope, and that when it ends, anything inside tumbles out.

We can safely assume that the 'tumbling out' occurs through the 3'x5' window that one climbs through to get into the space.

The Where

Functionally, anyone inside is tumbling out and down through that opening. Where they end up is going to be around that opening at the base of where the rope was.

The How

But how they're dispersed is going to be up to the DM. There aren't specific rules around this. But some things to consider are that they are going straight down and all at the same point. You could ask for Acrobatics checks to remain upright and not piled on the floor prone, but it wouldn't be unreasonable for everyone to be clustered together.