What are the 'Special Event Addenda' rules in Riftbound and can stores apply them to any event they host, such as allowing dice/mobiles for scoring?

Ruling: Special Event Addenda rules are modifications to Tournament Rules that apply to specific large/special events (like the Houston event example), not to regular store events like Summoner Skirmishes. Stores cannot arbitrarily modify Tournament Rules for their regular events using Special Event Addenda.

Nuances:

• The Houston event's missed trigger rule modification is an example of legitimate Special Event Addenda use
• These are not blanket permissions for stores to modify TR as they see fit for regular play