REDU format ruling
Trap Master

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)FLIP: Select 1 Trap Card on the field and destroy it. If the selected card is Set, pick up and see the card. If it is a Trap Card, it is destroyed. If it is a Spell Card, return it to its original position.
Rulings
- This card can destroy a Trap Card on either side of the field. So if your opponent has no Trap Cards and no Set Spell or Trap Cards, you must destroy a card on your side of the field. If it is face-down Spell Card you must reveal it to your opponent, and it is not destroyed.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.