Game:

Trials of Mana (2020)

Duration: 0:30

445 views

4

[Quantum item]
To perform the glitch use the last item in a stack and interrupt the item use animation by starting a cutscene, loading a savefile, or getting staggered from an enemy hit. In order to interact with a quantum item, there can be no other items in the same item category.

[Stack dupe]
Once you have a quantum item, open the main menu and set the item that you want to duplicate to the ring menu (even if it's already set), then go to the quantum item and set the quantum to the ring menu. You should now have another stack of the target item. The stack's amount is set as soon as you stack dupe, so gaining/using an item resets the value back to the amount when the stack was duplicated. If you use/sell an entire stack, it only removes a single stack at a time.


-- Speculative Explanation --

[Item stacks]
The game has a system for tracking items. Items are tracked in multiple places — the hard stack (tracks the item stack's state; shown in the main item inventory/shop list), and various soft stacks (these are derived from the hard stack, eg. quick use menu/battle ring menu/battle quick use menu). Whenever you use an item, the hard stack is immediately updated at the start of the item use animation, but some soft stacks wait for the item use animation to play out before updating (eg. done for cosmetic reason in the quick-use menu; note that there are ways to force refresh these before they are automatically refreshed by the item use animation). If the item use animation has been interrupted in any way before this cosmetic update is done, a refund system is triggered.

[Refund System, aka item duping]
The refund system returns a single item of the kind you just attempted to use but **DOES NOT RE-SET THE STATE OF THE ITEM STACK IT'S UPDATING**. The refund system is extremely sensitive (it seems to be set up in a global way) and can be triggered simply by getting staggered from an enemy hit, starting a cutscene, loading a savefile (this enables item duping), etc... A crucial edge case of the refund system occurs when transitioning to 0 items of a stack. The game sets the internal state of the hard stack to [some inaccessible/disabled/non-interactable state?] immediately along with setting the number to 0, but then the refund system is triggered and quantum items occur — you have a [some inaccessible/disabled/non-interactable state?] stack of a non-zero number of items.

Other Statistics