Hmmmm it's probably best demonstrated with an example: if you have users a b and c, a normal rotation of a chore would be a b c a b c a b c ... and so on. If user b has 2X, the rotation would be a b b c a b c ... Does that make sense?

Assignment and rotation happens automatically. A chore is setup with a frequency, etc, then as users are assigned they are notified and they only need to intervene when they do the chore.