For the Riftbound release event: What is the sideboard composition, card copy limits, and sideboarding rules between games and matches?

Ruling: The sideboard consists of any cards opened from the champions deck plus 3 booster packs. You cannot run more than 3 copies of the same card. You can sideboard between games within a best-of-3 match, and since there is no registered decklist, you can change cards between matches.

Nuances:

• The release event is not a Riot sanctioned tournament and does not have qualifier implications, so specific rules may vary by LGS