the best pokemon gen 1 glitch is brock through walls, entirely because it's called "brock through walls"

you know the guy who prevents you from leaving pewter city until you fight brock and leads you right to the gym door? well, he has two different paths he can take depending on whether you're talking to him from the west or south

what happens if you talk to him from the east? it doesn't matter, he has a wall to his north and he stops you if you try to pass you on the south so you can't possibly get to the east.

anyway here's how to talk to him from the east:

- pause your game, put your cursor on "save", unpause
- walk in front of the guy and buffer a pause
- you'll notice that, while the game is paused, you can't move your cursor. good thing it's already on "save". save your game
- reset
- walk to the east

tada

now, when you talk to him from the east, he looks up which path he should take you on depending on your coordinates. but there's no path for talking to him from the east, so he ends up reading garbage data

and if you set up some memory in just the right way (for example, i thiiiink you have to have a move with 16 pp remaining in your lead pokemon's 3rd attack slot), the game gets put into a state where it thinks you're being led by an NPC but you actually have control. and while the game thinks you're being led by an NPC, it doesn't check collision while you move around the overworld

brock through walls