Oblivion:Scroll Duping

Scroll Duping is a glitch that allows you to duplicate an item into several copies of itself when dropped by manipulating a stack of scrolls.

Instructions

Select a scroll stack that has at least 2 of the same scroll from your inventory.
Without exiting the inventory, drop an item you want to dupe that is in a smaller stack than the scroll stack you selected.
Exit the inventory and the chosen item will be dropped in a stack the size of the scroll stack.

If you accidentally select a few different scroll stacks in a row, you may have to exit and open your inventory and try the glitch again.
This glitch will not work on certain items, including weapons/armor that have been damaged/repaired.
It is faster and less laggy to dupe a stack of an item rather than a single item when duping up to a large quantity. Try duping a single item with a smaller scroll stack first, and then dupe that larger stack of that item again with a larger scroll stack. Duping a single item with a 200+ scroll stack may crash the game.