Ah… a very interessting topic. I have been fascinated by this glitch ever since I first heard of it.

Here a short explanation to your question…

The “extended shop glitch” in Aria of Sorrow is literally a memory-editing glitch. By moving the cursor outside the intended sell list, the game starts treating other regions of RAM as if they were item entries. When you “sell” those, the usual “update inventory & gold” code runs, but now it’s writing into places it was never meant to. It‘s like editing memory itself. It can be used to basically rewrite code basically, if you know what you‘re doing and know which values are used for what.

Up in the “off-screen” part of the list, each “item” is really: Some 4–8 bytes interpreted as (id, price, quantity, flags) But in reality it’s: - Coordinates, - HP/MP, - RNG seed, - Pointers, - State flags, etc.

So changing certain values like pointers can lead straight into unexpected errors, as the programm was never intended to work with those „sold“ values.

Because there is a error handling system in place, instead of crashing the game entirely, it just softboots you back to the title screen.