Oblivion:Patched Glitches

This article contains glitches that have been fixed by official patches.
Exploitable Glitches
These are glitches that can result in a player advantage of some form.  It does not include various ways to take advantage of intentional game features, because such exploits are not glitches.
Duplicate Items Using Arrows
 
Step-by-Step Guide
This assumes that you wish to duplicate a single item.  Using the glitch on an entire stack of one item will work as well, but entails some complications; see below under "Exact Calculations".
# You need an instance of a droppable item (i.e. non-quest item) and a stack of arrows in your inventory.
# Equip the arrows.
# Perform an attack, such as:
#* Throwing a punch.
#* Swinging a blunt or blade weapon.
#* Firing a staff.
#* Casting a spell.
#* Drawing an arrow on a bow.
# While the attack is still in motion, quickly enter the journal.
# Attempt to unequip the arrows (not drop, unequip). You should get a message that "You cannot change weapons while attacking". (Otherwise go back to Step 2 and try again.)
# Drop the item you wish to duplicate from your inventory.
# Either leave the journal or repeat steps 5 and 6 for other items you wish to duplicate.
Once you leave the journal, as many duplicates of the item will be dropped into the world as there are arrows in the equipped stack.
Exact Calculations
If this glitch is used on a stack of items, things become slightly more complex.  The game will still drop as many items into the world as there are equipped arrows, but they will be grouped in stacks and, depending on the circumstances, a smaller stack may remain in the inventory.

Most of the stacks will contain as many copies of the item as were in the player's inventory (including any equipped copy), but unless the amount of arrows was an exact multiple of that number, the last stack dropped will contain a smaller number, namely the remainder needed to fill the exact number of arrows.  The content of the last stack, whether it is smaller or identical to the others, is what will be removed from the player's inventory.  Thus the process in the Step-by-Step Guide is really a special case with stacks of size 1.

If the last stack is not a smaller remainder, all copies of the item will be removed from the player's inventory immediately, even if one of them is equipped at the time and should be unequipped first.  This can be exploited as well, to gain permanent effects from enchanted items.

While complicated, if you can figure it out, you may find that duplicating multiple copies can be beneficial.  The game will lag if there are many items in the cell at one time, often causing the game to freeze up if you duplicate too many.  Dropping these items in stacks will help avoid that.

Examples:

Amount of arrows equipped: 50 
Items in Inventory: 60 Daedra hearts 
Items dropped: 1 × 50 Daedra hearts 
Left in Inventory: 10 Daedra hearts (=60-50) 
(Note that no duplication takes place.  This is the same as dropping an item normally and answering "50" to the question "How Many".)

Arrows: 50 
Items: 1 Ring of Perfection 
Dropped: 50 × 1 Ring of Perfection 
Left: nothing (=1-1)

Arrows: 50 
Items: 10 potions 
Dropped: 5 × 10 potions 
Left: nothing (=10-10)

Arrows: 50 
Items: 6 Hammers 
Dropped: 8 × 6 Hammers + 1 × 2 Hammers (=50) 
Left: 4 Hammers (=6-2)
Notes
Copies of a piece of clothing, armor, or jewelry obtained through duplication can not be equipped at the same time, however, copies obtained through normal means can.
Instead of trying to unequip the arrows, you can also attempt to equip a different stack of arrows, which has the same effect.
Weapons and Armor need to be at 100% health or less to be duplicated.  Items at 125% health (i.e. items repaired after you have the expert level Armorer perk) will not duplicate.  One way to reduce an item's health to exactly 100% is to ask a smith to repair all of your equipment for you (using the "Repair All" option): even items at 125% health will be "repaired" to 100% health.
A video of this trick is available.
If the quantity of cloned items is very large (over 100) the game is very likely to freeze and not recover. It is safer to use a smaller number of arrows and simply repeat the cloning multiple times - or duplicate a stack, as described under "Exact Calculations".
Good items to clone are those that are expensive but lightweight.  Examples: Varla Stones (1000 gold, weight 1), Poisoned Apples (300 gold, weight 0), filled Grand Soul Gems (500 gold, weight 0.5), and Flawless Diamonds (100 gold, 0.1 weight).
Duplicating a lot of Sigil Stones may cause massive lag. (Because they flash and glow, so a lot of them at once will make the game lag a lot.) Also when you drop them inside they tend to disappear.
Lockpicks will also cause the game to lag. Duplicating just 10 makes the game skip a few frames. Try to duplicate Lockpicks in stacks for best results.
Black Soul Gems have a unique reaction to the duplication trick.  When you duplicate them, they tend to flip out and take off, bouncing off what they hit; try this indoors.
This trick can be used to duplicate paint brushes, which can be later used with the floating paint brushes glitch.
Cloning will only work with some enchanted items.  Enchanted rings that have been cloned include the Ring of Khajiiti, the Ring of Sunfire, and the Jewel of the Rumare
Items that can not be cloned include Nirnroot.
Sometimes if an item will not clone, sell it to a shop, buy it back again then try again. This usually works.
Infinite Money Glitches
Glitches which you can use to get infinite amounts of gold.
Infinite Money - Dorian
 
Infinite Money - Kvatch
 
Infinite Money - Vampirism
 
Problematic Glitches
Significant problems that can prevent further gameplay but not result in a player advantage.
Caught in the Hunt Glitch
 
Clavicus Vile Glitch
 
Reference Bug
 
Minor Glitches
Minor problems that do not affect gameplay to a great deal.
Skill Level is Frozen