Oblivion:Skill Underflowing

Skill Underflowing

Category: Player Stats

Also Known As: Underflowing

Version Compatibility

v1.0	v1.1.511	v1.20214	v1.2.0416
?	?	?	✔

Required DLC Images will go here.

Details

Found By:	MeemawHustlin
Date Found:	9/23/2021
Archaeologist:	N/A
Date Recovered:	N/A
Original Source:	Link

Skill Underflowing is a glitch that allows the player to reduce a skill's base value below zero, resulting in the integer value underflowing back to the maximum integer value of 255.

Instructions

There are two currently known ways to underflow skills, either by using the Class Reset glitch, or by using the Molag Bal Glitch.

Class Reset Method

1. Acquire some combination of the Underflowable Boosts listed below.
2. Perform the Class Reset glitch, making sure that any skills you desire to underflow are reset to values less than the total boosts you have acquired in step 1.
3. Remove the acquired boosts using the appropriate means, either dropping the Skeleton Key or drinking the Cure for Vampirism potion.

Molag Bal Method

1. Acquire some combination of the Underflowable Boosts listed below.
2. Steps will be added in soon.

Mechanics

Underflowable Boosts

There are several free skill boosts in the game that are incorrectly programmed to give the player boosts to a skill's base stats rather than fortifying it as a magic effect. These types of boosts are what makes underflowing possible:

Boost	Skill Bonuses	Acquired From	Class Reset	Molag Bal	Removed Via
Skeleton Key	+40 to Security	Nocturnal quest	✔	✔	Dropping the Skeleton Key
Vampirism	+5 to +20 Acrobatics, Athletics, Destruction, Hand to Hand, Illusion, Mysticism, and Sneak	Getting/developing the disease to the final stage.	✔	✔	Drinking the Cure for Vampirism
Night Mother's Blessing	+2 to Acrobatics, Blade, Marksman, Security, and Sneak	Whodunit? quest	✘	✔	Molag Bal Glitch
Gray Prince's Training	+3 to Athletics, Blade, and Block	Origin of the Gray Prince	✘	✔	Molag Bal Glitch

Effectively, this means that we currently know how to underflow 11/21 skills in the vanilla game. (Acrobatics, Athletics, Blade, Block, Destruction, Hand to Hand, Illusion, Marksman, Mysticism, Security, and Sneak). However, small boosts like Night Mother's Blessing would require that your skill be at 1, which is only possible if you can reduce your skill down first. Due to a bug, the only skills that can be reduced by spending time in jail are Armorer, Athletics, Blade, Block, Blunt, Hand to Hand, Heavy Armor, Alchemy, Alteration, each with a decreasing chance. The RNG required to reduce specific skills to 1 is likely going to take more time than leveling those skills via training.

DLC Underflowable Skill Boosts

The DLC adds a number of additional skill boost in the form of abilities. Additionally, it adds a second cure for vampirism, which is much faster to complete, however it also prevents you from completing the original quest, rendering it useless for 100%.

It also adds a duplicate method of performing the Molag Bal glitch, where you can die in the Isles using Sheogorath's Protection and respawn without any permanent abilities.

Boost	Skill Bonuses	Acquired From	Class Reset	Molag Bal	Removed Via
Dwemer Fireheart	+15 to Armorer	Battlehorn Castle Dwemer Forge	✔	✔	Leaving the forge area
Alchemical Brilliance	+15 to Alchemy	Frostcrag Spire Alchemy Lab	✔	✔	Leaving the alchemy area
Crusader's Arm	+10 to Blade or Blunt (mutually exclusive)	Sword and Mace of the Crusader	✔	✔	Unequipping the weapon

The only interesting option is the Alchemy lab, as most combat skills can be maximized at level 135 with a female Orc and specialization in combat and reading the Oghma Infinium. You can permanently receive the ability at the Dwemer Forge or Alchemy Lab by standing near the location and then load warping away (where you would presumably class reset). In order to remove the permanent ability, simply go back to the original location.

Both the Sword and Mace of the Crusader can apply their respective abilities at the same time, but as soon as you exit the inventory the bonuses will go away if you don't have the respective weapon equipped. If you can somehow open the class reset dialog while in your inventory, it might be possible to underflow both at the same time.

DLC Underflowable Attribute Boosts

Underflowing Attributes is significantly less useful, as Attributes are not required in the 100% speedrun, and would only help with movements peed, carry weight, combat, or magicka, all of which can be improved with Permanent Enchantments.

Boost	Requirement	Strength	Endurance	Speed	Agility	Personality	Intelligence	Willpower	Luck
Vampirism	Vanilla game, Porphyric Hemophilia	+20		+20				+20
Greenmote	Ritual of Mania Quest	-10	+10	+10	-10	+10	-10
Felldew Euphoria (addicted)	Addiction Quest/Felldew	+20			+20		+20
Felldew Euphoria (cured)	Addiction Quest/Felldew	+5			+5		+5
Ruinous Felldew Withdrawl	Addiction Quest/Felldew	-15	-10	-10	-15		-15	-10	-15
Jyggalag's Ascendancy	Eat a Heart of Order	+25
Storm's Fury	The Prince of Madness Quest/Manipulate Weather	+20	+20	+20	+20
KotN Blessings	Umaril the Unfeathered Quest	+5	+5	+5		+5	+5	+5	+5

Due to how class reset works, any positive bonus is actually a *negative* when it's removed, and any negative bonus is actually a *positive* when it's removed. So resetting your class during a Ruinous Felldew Withdrawal will permanently increase your attributes significantly, or it can be used to temporarily lower your stats after you lose Felldew Euphoria. However, acquiring Greenmote requires you to be cured of your Felldew addiction, which means you can't do both. Much of the sources require completing a significant portion of the game, which may mean it's not worth attempting to underflow in a speedrun setting.

Strength is very easy to underflow, however, with Felldew and a Heart of Order, providing -45 strength combined, and can be picked up relatively quickly in the Shivering Isles questline. You can also subtract 15 strength via Ruinous Felldew Withdrawal for an easy -60, but the extra 15 will be lost when you complete the Addiction quest.

A Female Breton (30 str, 30 end, 40 spe) can theoretically underflow all 3 attributes by combining all non-felldew options.

Class Reset Mechanics

When a Class Reset is performed, it resets the player's stats based on their current level among many other factors. Since the base stats are altered by these skill boosts, Class Reset effectively ignores them when calculating the new skill values, but keeps their effects active on the player. For example, the Skeleton Key gives +40 Security, so if the player Class Resets and picks Security as a minor skill, Security could for example be reset to 39 (it is based on player level and will not always be this value.) However, since the base stat is now 39, and the Skeleton Key is still on the player, the player currently has a +40 Security boost for a total of 39 Security, meaning that if the player then drops the key, they will lose 40 Security, resulting in a final total of -1. Skills are unsigned 8-bit integers, which means that they can only be a positive value from 0-255, so a value of -1 is interpreted as rolling backwards from 0 to 255. This is what results in the final desired effect of skills underflowing to a very high value.

Ongoing Work

Fevus — 2021-10-11 1:27 PM found something, if we decide to use dlc content, greenmote can be used to fortify personality, speed, endurance by 10 base which we can remove with level scaling glitch so we could start with base 15 personality and maybe we have enough to underflow speed now