Can a Teleport spell to a false destination have no similar area?

Question

I am struggling a bit to grasp the limits of the "similar area" definition in the description of the teleport spell for D&D 5e.

The part I have a problem with is more specifically with the "area that's visually or thematically similar to the target area".

For example if the caster was in the elemental plane of fire and tried to teleport to some kind of Oasis that he would have been tricked into thinking exists on that plane what happens?

Does it get teleported to the closest lava pool with a shape somewhat similar to where it thought it was going? Does it get teleported to the water it has in its backpack or does the spell fails?

With the definition of the spell I would assume that if anything on the plane has some kind of link with the target area that the DM can think of, it should be allowed to be defined as a similar area, but some situations may have some really messed up link and I wonder if in extreme cases it isn't more logical to have the spell to fail.

Answer 1

There is a lot of DM-leeway in what this spell does.

"Visually or thematically similar" is incredibly broad, as long as you don't take the description literally. The example given in the spell suggests that teleporting to your laboratory could take you to an alchemist shop just because it contains the same kind of equipment. It also says that you could wind up anywhere on the same plane so distance isn't a factor.

In the case of an oasis:

There could be somewhere on the plane that contains a place to get water - e.g. an outpost of the Efreet such as the City of Brass, which very likely has an area capable of supporting non-natives (with a magically supported water fountain).

Or you could simply take it to mean an 'area of respite from the flames' and take you to a (relatively) cooler area in a structure built by some other long-forgotten planar travelers.

Really, the only limit is your imagination.