Oblivion:Leveled Lists

Leveling is a fundamental aspect of gameplay in Oblivion: as the player's character grows stronger, the rest of the game world also becomes more powerful.  This page describes the leveled lists that are used to implement changes in the world.  Details of the character's level are provided on the Leveling page.

Overview
The leveling system used in Oblivion undoubtedly has both pros and cons.  Whatever your opinion of the system, it is an inescapable part of gameplay (at least without installing major overhaul mods).  There are multiple ways used to implement leveling, most of which can overlap or otherwise integrate with each other.  This page documents most of the features of the leveling system.

The actual leveled lists used in the game are not listed here.  For creatures, the leveled lists specific to each creature category are listed on the appropriate page (i.e., on Animals, Daedra, Goblins, Monsters, and Undead); leveled lists used outdoors are listed at Outdoors Creatures.  For items, the various item pages all document the level at which a given item appears in leveled lists.  The standard leveled lists used for non-magical Armor and Weapons are provided on each of those pages.

Creatures
Individual Leveled Creatures and NPCs
Some creatures and most NPCs have statistics that are variable depending upon the player character's level.  The identical creature/NPC encountered at a later level will have better statistics (for example, if you choose to sleep for an hour in the Fighters Guild in order to level up, when you awaken the other Fighters Guild members will also have increased in level).

All creatures and NPCs have a level; for many creatures the level is fixed.  For individually leveled actors (creatures or NPCs), the level is set to be a fixed offset relative to the player character's level.  The actor's level is then used to determine its statistics.  Some actors have an upper or lower limit on their level.  The lower limit for an actor's level is always at least 
one.

In the case of creatures, the statistics that vary with level are:
Health = HealthMultiplier * CreatureLevel
Magicka = SpellPtsMultiplier * CreatureLevel
Fatigue = FatigueMultiplier*CreatureLevel
CombatSkill = Combat + 2*CreatureLevel
MagicSkill = Magic + 2*CreatureLevel
StealthSkill = Stealth + 2*CreatureLevel
Attack Damage = AttackMultiplier + 0.5*CreatureLevel
Soul is determined from the CreatureLevel, as discussed at Souls

Leveled creatures are generally used for the most powerful creatures in the game.  This ensures that even for high level characters (i.e., characters higher than the maximum level of any lists) the creatures continue to get more difficult.

In the case of NPCs, a much larger range of statistics vary with level.  NPC Statistics summarizes these statistics and how they are calculated.

Leveling of NPCs is almost always accomplished using this mechanism, so "leveled lists" for NPCs are strictly speaking not used.  However, there are many lists that are used to generate a random NPC.  For example, there are multiple different bandits that can appear at a given spot; which one appears is determined by randomly selecting from a specified list.  These lists are labeled as leveled lists, but character level does not have any effect on the outcome; it is purely random.

Fixed Creature Lists
In some cases, there is a single fixed creature that will be generated by a list depending upon the character's level.  In other words, at any given level there is one (and only one) creature that will be encountered.  These types of lists are often used for quest-specific or boss creatures.  Sometimes the name of the creature is the same at all levels; other times, the name varies to reflect the different creature.

Some examples of such lists are:
Minotaur of the Grove: always generates a minotaur identified as Minotaur of the Grove, but the statistics are different at different levels
Pale Pass Ogres: always generates an ogre, but the names vary (Pale Pass Ogre Groundling, Pale Pass Ogre Stonewrecker, etc) and the statistics vary.
Llathasa's Spirit: generates a different ethereal undead (ghost, wraith) that is always identified as ''Llathasa's Spirit
Sanctified Dead: generates different ethereal undead with different names (Sanctified Dead, Ancient Sanctified Dead, Sanctified Ancient Spectre'').

Random Creature Lists
These are the most common type of creature leveled lists, and are used to generate a random creature depending upon the character's level.  So at any given level there will be multiple creatures that can possibly be generated; the exact one that appears is determined randomly.

Each creature in a leveled list has an assigned level.  That level is lowest character level at which a creature will be encountered.    As the character's level increases, more difficult creatures will start to appear.  At the same time, lower level creatures may drop off the list of possible creatures.  The parameter   determines when low-level creatures disappear; this parameter is by default set to 8 (but could be altered by mods).  It provides the maximum difference in level between the highest level and lowest level creature that can appear.   Once the list of possible creatures is determined, there is an equal chance for any of those creatures to appear.

To demonstrate how this works, the following table shows the probability of any monster appearing based on the standard monster leveled lists (specifically, LL1MythicEnemy100).

For this particular list the total chance of encountering a creature is 100%; there are other versions of the list with 75% (LL1MythicEnemy75), 50% (LL1MythicEnemy50), or 25% (LL1MythicEnemy25) chances of a creature existing.  So, for example, if a location specifies that a LL1MythicEnemy25 creature exists at that spot, a level 8 character will have a 75% chance of finding nothing, a 12.5% chance of finding an imp, and a 12.5% chance of finding a troll.

The minotaur entry in the LL1MythicEnemy100 list has a couple extra layers of complication.  First, there are actually four different varieties of minotaurs that can appear whenever a minotaur is generated.  Second, there is a one in three chance that the minotaur will carry a weapon.  These options do not increase the likelihood of minotaurs appearing relative to other monsters because they are accomplished by nested leveled lists.  So the LL1MythicEnemy100 list shown above does not directly include minotaurs in the list but instead includes a reference to the list LL1Minotaur100, which contains 2 entries for an unarmed minotaur (LL0Minotaur100DUPLICATE000)and one for an armed minotaur (LL0MinotaurWeapon100).  The LL0 lists then list the four different minotaur varieties.

The pages on this site provide information on each creature's standard level.  This is the level at which that creature is first encountered in the standard leveled lists (i.e., the most commonly used lists); the pages detailing each creature has a section on "Leveled Lists" that provides specifics on the standard leveled lists.  However, there are hundreds of variations on the standard leveled lists that can be used in specific situations.   For example, even though Daedroths are normally not encountered until level 16, they can be encountered at level 10 in the count's quarters of Kvatch Castle where a specialized list is used.

The maximum 8-level difference means that level 1 creatures, such as Imps, Deer, and Rats, are less common for level 20 characters than level 1 characters.  However, it does not mean that such creatures are never encountered, because of several twists in the leveling system:
Some lists only include relatively weak creatures.  For example, on the Outdoors lists used in valleys, the most dangerous creature is a Timber Wolf (level 6).  Since the 8-level difference is applied relative to the creature of the highest level on the list, this implies that imps are always possible using this list.
Weak creatures are sometimes duplicated on lists at higher levels in order to ensure that they can always be generated.  For example, Deer are included multiple times in all of the outdoors lists.  On LL1WildernessPlains, Deer are listed at level 1, 8, and 17.
Weak creatures are sometimes added by nesting lists within another list.  For example, the LL1MythicEnemy100 list is nested within the LL2MythicEnemyLair100 list, which specifies that there is a 1 in 5 chance of a Rat appearing instead of a leveled monster.  Any given cave will generally include a mix of different types of lists, some nested and some not.

Items
Leveled lists are used to generate most items in containers and NPC inventories, although some items are fixed. Most of the features available with creature leveled lists are also available for item leveled lists. In particular, item lists can also be nested in many different ways, resulting in a complex system.

Leveled lists cannot be used to generate items that sit out in the open, so anything on a bookshelf or table is a non-random item. 

The contents of an area's containers are determined when you enter that area (i.e., when you open the door and a load screen appears). While you wait and stare at the load screen, the computer goes through everything in that zone and determines its contents. If you have never visited the area, a set of contents will be generated. If you had visited the area previously but the conditions for respawning are met, a new set of contents will be generated. Otherwise, the game loads the previously-determined contents from your save file. 

The equipment carried by NPCs is determined by the lowest level between the NPC in question and the player, as detailed in 
 .  In other words, boss-level NPCs will not carry better equipment than otherwise available, but very weak NPCs will carry unusually poor quality equipment.

Although the level of any specific item does not vary with time, the skill system imposes a similar variability.  A character's proficiency with using an item, as described by skill and attribute statistics, determines the actual usefulness of the item.  For example, the amount of damage done by a sword is determined by the character's Blade skill and Strength attribute.  A sword first acquired at low levels may only do 5 pts of damage; the exact same sword later in the game could do 15 pts of damage.

Fixed Item Lists
For some items, there is a single specific item that will appear depending on the character's level; at any given character level there is one and only one item that will appear. Many of these items are listed at Leveled Items. The item is determined at the time you receive it; a leveled item received at level one continues to be the low-level item for the rest of the game, and will not be updated when your character levels up. The only exception to this is the Crusader's Armor in the Knights of the Nine official mod, which can be updated using the armor stand. There are also unofficial mods such as the   mod that allow leveled items to change each time a character levels up.

Random Item Lists
Random item leveled lists are used when there are multiple possible items that could appear for any given character level.  The list of possible items is determined based upon the character level, and then one is randomly picked.

As with creatures, there is a parameter (in this case  ) that sets the maximum difference between the highest level and lowest level items that can appear.  By default, this parameter is set to 8.

The following table demonstrates the probability of any particular type of weapon appearing according to the standard weapon leveled list, LL1LootWeapon100.  Note that elven weapons actually appear twice in this list, at level 9 and again at level 18.  This ensures that elven weapons continue to appear even for the highest level characters.