What do you do when you like the idea of a rule more than the rule itself? You modify it, of course. I like the idea of the Birth Augur and Lucky Roll of Dungeon Crawl Classics RPG (see table 1-2 in the rules), but I prefer one based on zodiacal signs rather than a hodgepodge of signs and circumstances ("the bull," "unholy house," "raised by wolves," "conceived on horseback," etc.)
Below are two alternate tables representing the most common forms of astrology in our world. Either could be modified to suit the particular requirements of a fantasy world by substituting appropriate flora, fauna, or figures of that world's mythology.
Zodiac Sign and Lucky Roll (Western Astrology)
Roll 1d12
1. Aries (Speed (each +1/-1 = +5'/-5' speed))
2. Taurus (Fortitude saving throws)
3. Gemini (Detection checks)
4. Cancer (Armor Class)
5. Leo (Melee attack rolls)
6. Virgo (Will saving throws)
7. Libra (Reflex saving throws)
8. Scorpio (Initiative)
9. Sagittarius (Missile attack rolls)
10. Capricorn (Damage rolls)
11. Aquarius (Skill checks)
12. Pisces (Spell checks)
Zodiac Sign and Lucky Roll (Chinese Astrology)
Roll 1d12
1. Rat (Armor Class)
2. Ox (Fortitude saving throws)
3. Tiger (Damage rolls)
4. Rabbit (Reflex saving throws)
5. Dragon (Hit points (applies at each level))
6. Snake (Spell checks)
7. Horse (Speed (each +1/-1 = +5'/-5' speed))
8. Goat (Initiative)
9. Monkey (Skill checks)
10. Rooster (Attack rolls)
11. Dog (Detection checks)
12. Pig (Will saving throws)
