What is Fallout's Graphical Projection?

Fallout (1997) Game Cover via Moby Games

With the recent release of Amazon Prime's Fallout series, I started to re-watch video reviews and interviews from the original Fallout role-playing game that the TV series is derived from. Despite having never played any of the games, I was always a fan of the design and artwork.

From the videos I reviewed, I noticed a misunderstanding of the type of graphical projection Fallout used. 

From LGR's review, Clint Bassinger states:

Now, you’ll see some refer to Fallout’s aesthetic here being isometric, but technically it’s cavalier oblique projection. This perspective was chosen in order to better suit the hex-based areas you’ll be navigating and it works quite well for what it is. 

Timothy Cain, the original creator and lead programmer of Fallout, describes the origins of the game as being isometric:

I went back to good ol’ sprites, and 2D, isometric… and uh, starting to put together just a little isometric game. 

So what type of projection was it? To lay this to rest, I grabbed a screenshot of the game and overlayed an axonometric grid in Affinity Designer.

Affinity Designer's Grid and Snapping Axis pallet.

Designer has several presets including isometric and axonometric, but I used the cube mode to visually overlay the grid over geometric features in the screenshot. 

Fallout screenshot with axonometric grid overlay.

The different angle values told me the answer I was looking for, the projection for Fallout is trimetric. 

I don't blame Tim Cain for saying isometric because it's common practice to use that term to mean a projection that is not in perspective. But Clint went out of his way to say it's not isometric but rather another projection type which was incorrect anyways. A rare misstep, as he's usually on top of his research and technical information.