The only such rules are Drow Women are not allowed to be caught in an enemy household, or else it is up to the Matron to deal with them accordingly. This doesn't forbid..by ALL MEANS go ahead! To stop all-out war, the matrons aren't allowed to participate. Fun for the family! The outskirts are available for hiding, in addition to the city state; if a male is unable to easily get to whichever Drow House they prefer. Cavern entrances are sealed off magically during the holiday season, restricting runaways while also doubling as a layer of protection for the city state from outside dangers.
In essence, a consort contest; chances to abduct your mate or kill off any you can't get.
Some good pregaming that is cutting deals with specific houses to try setting up contracts beforehand, but ofcourse, in many cases SOME betrayal tends to occur. This becomes an excellent time in a Drow's life to see whether they will live comfortably in a high-yield Drow house or get picked off by the other bachelors or bachelorettes. This is a race; each of the main houses in a Drow City State cast a spell lighting up the lichen lights above their households, signifying that their youngest boys are ready to run out into the wild. Only when all of the lichen lights are lit are the great gates of each household opened up for the men to go running out - carefree and running for their lives. During these 8 eights of the hunt - it is left to both the men & women to do their best. For the guys, it is up to them to either run away from or be found by the houses that are worthy enough for them - or the first to capture them. During this time, any and we mean ANY Drow consort is on the table. This does include Drow Favored Consorts.