Statistics
Strength
Modifies the character's damage roll. While this is typically a bonus, it is a penalty at particularly low values.
Adds a bonus to the character's carry capacity.
Determines the maximum weight a character's mainhand weapon can be.
Intelligence
Modifies the character's armor class. While this is typically a bonus, it is a penalty at particularly low values.
Reduces all mana costs.
Increases passive mana point recovery.
Wisdom
Modifies the character's saves. While this is typically a bonus, it is a penalty at particularly low values.
Adds a bonus to all forms of active mana recovery, such as cantrips or Brawler's Renewal.
Grants a bonus to healing effects.
Dexterity
Modifies the character's hit roll. While this is typically a bonus, it is a penalty at particularly low levels.
Reduces all move costs.
Increases the range of weight a character's offhand weapon can be when dual wielding.
Constitution
Grants a chance to resist poisons.
Increases passive hit point recovery.
Increases the character's maximum death total.
Charisma
Modifies the character's prices when purchasing from shops. While this is typically a bonus, it is a penalty at particularly low levels.
Increases the character's chances of a successful reward with sacrifice.
Increase the caster level of spells cast.
Hitroll
Hitroll represents your chance to hit a given target. This chance is reduced by the target's armor class, parrying, and dodging abilities. Factors that increase your hitroll include: dexterity, various skills and spells, weapon quality, and enchantments on items or weapons.
Damroll
Damroll represents various factors that increase the damage you do with every physical blow. Things that increase your damroll include: strength, various skills and spells, weapon quality, and enchantments on items and weapons.
Armor class
Your armor class, visible with the 'SCORE' command, tells you how well-armored you are against the physical and magical dangers of the world. It is a combination of natural intelligence, the protection offered by worn items, and magical enchantments or enhancements. Your AC is also affected by your body position--sleeping characters have worse AC.
The lower (more negative) your AC number is, the more effective your armor will be at reducing damage, as a percentage value, with increasing returns for lower values. Against lesser opponents it may help to avoid being hit altogether. On the other hand, having an AC higher than zero will increase vulnerability to damage.
Hit points
Run out of them, you're dead. All classes gain the fast healing skill that improves passive health regeneration.
Mana
A resource used to fuel most active abilities and spells. All classes gain access to the meditation ability that improves passive mana regeneration, and some classes gain trance which improves it further. Some classes also gain active mana regeneration, such as cantrips and Brawler's Renewal.
Movement Points
A resources consumed when walking from room to room, and fuels some abilities. Walking over difficult terrain consumes more movement points, but this can be mitigated by flying. A few classes gain abilities that improve movement regeneration. If your movement is drained, you cannot walk from room to room.