Question: I played in a game recently where the group did not roll the dice to break the wall. Is this a House Rule?

Answer: Yes, if a group does not roll the dice to “Break the Wall”, it is considered a House Rule. Just keep in mind that “Breaking the Wall” was implemented to avoid cheating. It can be compared to cutting a deck of cards. Cheating would take place during the building of one’s wall. The Cheater would in this case have to be East. While East built their wall, they could place a few Jokers in the first stack of four tiles which, they and only they would be picking.

Mah Jongg Made Easy 2024, page 9, BUILDING AND BREAKING OF THE WALL AND USE OF DICE

See also ID53, The League on House Rules.