Other than my various flavors of homebrew over the years, it was probably Empire of the Petal Throne.

Second to that would be the Albedo TTRPG.

I did this in a novel I wrote, actually. I assigned TLA 'names' based on their job (ENG, PIL, etc), and any time a gender would normally be referenced in the text I used XXX - both for easy searching. I got about 70% of the way through when my beta readers rebelled - they absolutely HAD TO KNOW what gender everybody was. Sigh.

But by this time the characters' personalities and speech patterns were well established, so I flipped a coin for each one, and continued onward. I'll probably do this again some day and just ignore the beta readers.

Argh! Ow.

As a gryphon who is very tired of seeing dragons everywhere... I love this.

And yet... people buy modules all the time. I always thought that turned into a board game.

I really enjoyed the few games of (1st edition) Traveller I got to play. Most fun I've ever had dying during character creation. Repeatedly.

Why would they need to make sense? That's clearly not a requirement here.

Chaotic Neutral. People freak out (chaos) due to ignorance (neutral).

Pencil and paper.

"Dragons? Even less so!"

"What if there are gryphons?"

"Now you've got my interest."

I was very fond of Albedo. Still am! Empire Of The Petal Throne was also one helluva great setting. Complicate rules, but that's not always bad.

Empire of the Petal Throne. It's just so wonderfully strange. Also very fond of Traveller, because where else can you die during character creation?