My favorite is the Doom random number generator, which is just a list of “random” numbers that it cycles through and if you know how to use it, you can do things like concentrate BFG attacks.

decino made a video about that, and at 13 minutes in the video they show what happens in-game if you set all values to 0 :)

https://www.youtube.com/watch?v=pq3x1Jy8pYM

:)

the closely related not-at-all-random fizzlefade from Wolfenstein: https://fabiensanglard.net/fizzlefade/

EverQuest also used pre-generated numbers. The randomness was derived from the large number of players using the same list.

That sounds like a pretty strong source of true randomness, frankly.

(It's then filtered through the list, so the list needs to have good pseudorandomness properties anyway, but still.)

Reminds me of a "Dice" electronics kit I assembled when I was a kid. It just used some standard sequential counter ICs run at very high rate. Pressing the "roll" button would just stop the counter!