So, I was playing D&D yesterday, and something happened that kind of bugged me. There was a disagreement on how the area of effect from thunderwave works. I'm no expert on the rules, but I thought that it was a square outward in one direction from the caster, like it's in front of them. They way both the DM and the player who cast it said it worked was that the square appeared centered on the character that cast it. Does anyone know which is true?

"Areas of Effect" in the PHB:

Cube

You select a cube's point of origin, which lies anywhere on a face of the cubic effect. The cube's size is expressed as the length of each side.

A cube's point of origin is not included in the cube's area of effect, unless you decide otherwise.

Spheres originate from the center and move outward. Cubes originate from a surface of the cube. Thus the Thunderwave cube is adjacent to the caster, not on top of them.

Thanks!

Might help to show them Thunderclap as a contrast.