A: In the vast majority of cases, when a duplicate Rule is played, it simply replaces the previous one, yet causes no change. For example, if Draw 2 is in play, and someone plays another Draw 2, it would replace the old one, and the old one would go into the discard pile, and the Draw would remain at 2 cards per turn.
Functionally, this would have identical results to playing your Draw 2 directly into the discard, and leaving the old one in play. You could choose to execute it that way, but it is important to remember that it is NOT a discard: it counts as one of your Plays, it just doesn’t make any change to the game state. For this reason, we recommend going through the formality of removing the old copy to the discard pile, and playing your new version to the table – at least at first, while you’re still getting used to the concept.
EXCEPTIONS to this would be if you played a new copy of Let’s Keep Doing That or Double Agenda, since these Rules have other cards associated with them which, when you play the new copy, would give the opportunity to change the associated cards.
• Let’s Keep Doing That (LKDT)
Put the old copy and its associated Action into the discard pile, and play your new LKDT. Then look through the discard for whatever Action you’d like to associate with your new play. Yes, you may choose to attach the same Action that was there before if you want.
• Double Agenda
… (ruling TBD)