Guild Wars 2

“Vapor Blade can hit twice (once on the initial path, and once when it returns to you). "
So it should be.

If any obstacle is in front of you or behind your enemy (e.g. a wall), the blade is not coming back (just one hit).
Is that intentional?

It makes sense that the projectile gets destroyed when it hits an obstacle..

LittleZoe.4970:

It makes sense that the projectile gets destroyed when it hits an obstacle..

Not really. If it can fly right through a heavily armored enemy without even slowing down, why would a nearby tree present any more of a challenge?

It’s also a very poor design from a gameplay perspective, since it halves both the damage and utility (vulnerability stacking) of that attack, punishing the Elementalist for fighting in enclosed areas, which seems to me would be the ideal place to use the dagger main hand.

Whether or not this is the intended function of the skill, I can’t really say. If so, it might be worth looking into changing how it handles obstacles. I can only assume that they were following the “if a projectile hits an obstacle, then the attack is obstructed” model, but that only works with attacks that fly from their source to their destination and do nothing else. For attacks that return to their source after a certain distance, especially ones whose damage is split between the launch and return, it would be much better to have the entity detect the wall and return early than to simply destroy it.