When people speak of breeding in (or marrying for) good genetic traits, what comes to mind? Genius most of the time, and occasionally strong.

What many people miss is that of all the good genetic traits, attractive has the potential to be the most powerful.

Howso you ask? Most people's experiance with attractive is modest. Their male ruler gets a freebie +1 diplomacy. Yay... Nothing to complain about, but nothing to write home about either. This is because attractive's power is largely wasted on a male ruler. To see it really shine, it needs to be on a female ruler.

In addition to the previously mentioned +1 diplomacy, being attractive gives you one more, often missed, bonus: a +30 "Attraction to:" relationship bonus to adult males (and homosexual females).

This is a global bonus. All vassals, all courtiers, your Liege, rulers of other nations and even the freaking pope! +30 to them all for free for life.

The implications of this are HUGE since 95% of the people in power are male.

1. An attractive female rising to the throne is much less likely to suffer from revolts, pretenders and other forms of civil war. Her short reign penalty is completely nullified by attractive...and then some!
   
   
2. Once her reign is established, her realm becomes even more stable than normal. Vassals are less willing to form, join or remain in factions.
   The buffer in vassal opinion allows you to run harsher levy/tax laws and reap their full benefits.
   
   
3. Bishops are more likely to give YOU their taxes and levies rather than the pope.
   
   
4. You can carry more of a tyranny penalty without destabilizing your realm, letting you be more flexible with revokes and/or banishments.
   
   
5. You are more likely to find people willing to join your plots, or be within bribing range of wanting to join. This includes courts full of people who would normally despise you. (I've been able to plot to kill muslim rulers as a christian, and get plenty of muslim court members to help me do so)
   
   
6. Foreign rulers are somewhat less likely to attack you due to their generally higher opinion.
   Allies are more likely to come to your aid when called into war.
   
   
7. You are less likely to be excommunicated by the pope, even when running free investiture, freeing your Chaplin to either convert or research culture, rather than kissing the pope's rear.
   If you are in elective, your vassals are more likely to vote along with your wishes.
   
   
8. You are unlikely to be killed via plot as many people will be unwilling to join a plot against you.
   
   
9. Claimants are more likely to accept an invitation to your court.
   
   
10. Allies of your enemies are less likely to join them in a war against you.
    
    
11. Changing major laws (crown authority) and/or succession laws becomes easier when all your vassals like you.

The list goes on. If you can pick up Gregarious (an additional +5 global, plus another +5 to vassals plus a few extra points in diplomacy) and have a decently high diplomacy stat, the effect becomes even more powerful.

The easiest way to get an attractive female ruler is to be in Agnatic-Cognatic Elective. This will allow you to nominate anyone, including women. Breeding for attractive is the same as breeding for Genius and Strong.

If you have never had an attractive female ruler, give one a try!