Dragon Quest's Simplicity

So I watched a 45 minute speed run of Dragon Quest 1r. I am unfamiliar with the Japanese terms for Tool Assisted Speedruns and other techniques. I do believe, and I may embarrassingly be getting this wrong, that this is not exactly a TAS but instead manipulating the random number generator and redoing parts? I think I have to re-watch it and pay attention to the comments on the bottom again.

Clearing DQ1r in forty-five minutes is one thing, but what this video really did was remind me how puzzle-like the original Dragon Quest was. Figuring out where things were, what things did, how things worked together, how to best take out the enemies in those one-on-one fights — which is really key to the game's theme and design. So much was represented by so little and it really shows how much complexity can be performed in very simple rule sets. DQ1 remains an extremely inspirational game.