There are eight basic attributes in Oblivion and four derived attributes. In general, the term "attribute" is used to refer just to the basic attributes, rather than the derived ones. For example, the Fortify Attribute effect alters only basic attributes; there are separate Fortify Health, Fortify Magicka, and Fortify Fatigue effects that apply to the derived attributes.

All of them except Luck govern three Skills, as detailed in Relation between Attributes and Skills:

Agility
Endurance
Intelligence
Luck
Personality
Speed
Strength
Willpower
Each of these attributes has a base value and a current value. The base value is, generally speaking, the value without any active enchantments, magical effects, diseases, or other temporary modifiers. The current value, on the other hand, is the value after all such modifiers are taken into account. If the current value is different from the base value, then its value in your journal will be colored (green if boosted, red if negatively influenced).

The base value of each attribute normally can only range from 1 to 100. Each time your character levels up you have an opportunity to permanently increase the value of three attributes, up to the maximum value of 100. There are also a limited number of opportunities to receive attribute bonuses as rewards. Some of these bonuses (in particular, the Oghma Infinium) directly alter the attribute base values. The others are implemented as abilities with a Fortify Attribute effect. Because they are abilities rather than standard enchantments or spells, these bonuses are effectively treated as if they altered your character's base attribute values. Abilities are the only way to temporarily alter the base value of an attribute.

The current value of an attribute can be boosted past 100, and many, but not all, benefits of the attribute continue to increase for values greater than 100 (see Magical Effects on Attributes). Most aspects of game play are based upon the current value of the attribute.


Derived Attributes
The values of these attributes are quantities that are derived from the character's primary attributes. In general, it is possible to magically alter these derived values either directly (e.g., Fortify Magicka) or indirectly via the primary attribute (e.g., Fortify Intelligence).

Health
Magicka
Fatigue
Encumbrance

NPC Attributes
All NPCs have the same basic and derived attributes as the player character, although there are some differences in how those attributes are calculated and used, as explained at NPC Statistics.

In addition, there are some attributes specific to NPCs that determine their behavior:

Aggression
Confidence
Disposition
Energy Level
Responsibility
In general, NPC attributes are not visible to the player within the game. The main exception is the NPC's disposition towards the player, visible from within Bartering and Speechcraft dialogues; percentage damage to an enemy's health is also visible when you are in combat. To obtain the other values, you must use the Console (for example, via the SetDebugText options) or the Construction Set. Values obtained in this way are listed on the individual articles for all of the game's named and unnamed characters.


Magical Effects on Attributes
Magical effects can be applied to attributes. These are:

Restore Attribute – An attribute can be restored only after it has been damaged. Restoring an attribute increases the value of that attribute up to that attribute's base value; it can only go above its base value if a Fortify Attribute effect is active.
Fortify Attribute – Fortifying an attribute temporarily raises that attribute's value above the base value; this temporary increase may go over the maximum value of 100.
Drain Attribute – Draining an attribute temporarily lowers the attribute below the attribute's base value. The attribute cannot be restored and is instead set to its original value once the effect is over. Although the attribute cannot be restored, it can be returned to its original value by dispelling (in the case of a spell) or curing (in the case of a poison) whatever is causing the drain.
Damage Attribute – Damaging an attribute reduces the attribute until it can be restored.
Absorb Attribute – The target's attribute is drained by a certain amount. The same attribute on the spellcaster is then fortified by the same amount.

Relation between Attributes and Skills
Although all attributes except luck govern three skills, the governing attribute does not have a direct effect on the skill levels. The one exception is luck, which invisibly alters nineteen of the twenty-one skill levels (every one except Athletics and Acrobatics). Although the character's journal pages will not show any change in values due to luck, increases in luck above 50 will cause larger effective skill levels, which are taken into account when calculating factors such as weapon damage and magicka costs. There's an absolute maximum of 100 in each skill. Therefore, a high luck attribute becomes less useful when your skills are close to master.

Several attributes do indirectly improve your ability to do the related skill. In particular:

Both the skill level and the attribute level are used to calculate the damage (The Complete Damage Formula) done with a melee weapon, which is determined both by the appropriate skill (blade or blunt) and by the strength attribute.
Similarly for bows, both the marksman skill and agility attribute determine the damage.
In other cases, the attributes have no effect on the skills:

Intelligence does not alter the characteristics of potions made using Alchemy.
Intelligence and willpower do not affect the magicka costs of spells, though a high willpower level will increase your magicka regeneration rate (see Magicka Regeneration for the formula used).
On the other hand, skill levels indirectly affect attribute levels. Using a skill allows larger attribute bonuses to be applied when leveling up.