Edison format ruling
Widespread Dud

Card effect (current official text)Select 2 face-up Attack Position monsters on the field. When any of the selected monsters are removed from the field, destroy this card. When this card is destroyed, destroy the selected monster(s).
Rulings
- "Widespread Dud" targets the 2 face-up monsters. The effect to destroy the targeted monsters does not start a Chain.
- If "Enemy Controller" is Chained to "Widespread Dud" and shifts one of the targeted monsters to face-up Defense Position, "Widespread Dud" will still resolve normally.
- Even if one of the targeted monsters is changed to Defense Position after "Widespread Dud" resolves it will still be affected by "Widespread Dud."
- If "Book of Moon" is Chained to "Widespread Dud" and flips one of the targeted monsters face-down, only the other one will continue to be targeted.
- After "Widespread Dud" resolves, when one of the targeted monsters is removed from the field "Widespread Dud" is destroyed and the other monster is destroyed.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.