Birth Signs

"Redguard" introduced the major constellations with a rather intricate puzzle involving figuring out where each of them was in relation to the others. "Morrowind" incorporates these constellations into a characteristic called a "Birth Sign." Those born under particular constellations (kind of like the zodiac) gain certain abilities, powers or spells. The manual that came with the game gives a decent general description of what you gain by being born under a particular sign, but here are the exact details. Again, abilities are always active, powers may be used once per day and spells go into your spell book.

BIRTH SIGN EFFECT
The Apprentice Abilities: Fortify Magicka (1.5 x INT), Weakness to Magicka (50%)
The Atronach Abilities: Fortify Magicka (2.0 x INT), Spell Absorption (50 pts), Stunted Magicka (cannot regenerate Magicka points)
The Lady Abilities: Fortify END (25 pts), Fortify PER (25 pts)
The Lord Abilities: Weakness to Fire (100%)
Spells: Restore Health (2 pts for 30 seconds on Self)
The Lover Abilities: Fortify AGI (25 pts)
Powers: Lover's Kiss (Paralyze 60 seconds on Target; Drain Fatigue 200 pts on Self)
The Mage Abilities: Fortify Magicka (0.5 x INT)
The Ritual Powers: Mara's Gift (Restore Health 100 pts on Self)
Spells: Blessed Word (Turn Undead 100 pts for 30 seconds on Target); Blessed Touch (Turn Undead 100 pts for 30 seconds on Touch)
The Serpent Spells: Star-Curse (Poison 3 pts for 30 seconds on Touch; Damage Health 1 pt for 30 seconds on Self)
The Shadow Powers: Moon Shadow (Invisibility for 60 seconds)
The Steed Abilities: Fortify SPD (25 pts)
The Thief Abilities: Akaviri Danger Sense (Sanctuary 10 pts)
The Tower Spells: Beggar's Nose (Detect Animal/Enchantment/Key 200 ft. for 60 seconds); Tower Key (Open 50 pts on Touch)
The Warrior Abilities: Fortify Attack (10 pts)