Can official Riot Riftbound Sleeves with holographic backs be used in tournaments, and does using matte outer sleeves over them make them legal?

Ruling: Official Riot Riftbound Sleeves with holographic backs violate tournament rules because reflective surfaces can accidentally reveal card information to opponents. The head judge at the event ruled them illegal even when double-sleeved with matte outer sleeves.

Nuances:

• The rule exists to prevent accidental information leakage through reflections
• Different events may have had different enforcement (some players reportedly used them at Houston regionals)
• Using matte outer sleeves (double-sleeving) was suggested as a potential solution but was still ruled illegal at this particular event
• Head judges have final authority on rulings at their specific events
• It's recommended to use proper opaque and matte sleeves for high-level events to avoid disputes