Tournament Play - Sideboards

[Rataskor]

I work at a game store and am responsible for running a day of wreckoning event this weekend. When looking through the information about tournament play, I noticed that it's up to the organizers and players to determine if the tournament will have best of one or best of threes.

In the case of a best of three tournament, are sideboards allowed? If yes, how many cards are allowed?

[Majobasil]

I am bumping this old thread because I am curious as well.

[Aleph]

There are no provisions or rules for sideboards in the official rules or in the tournament regulations.

From the Tournament Regulations:

Players in Constructed events must use this deck throughout the event; changes are not allowed.

Players in Select events can change their deck between rounds, but can only use cards they opened during the draft or sealed event.