Goat format ruling
Fissure

Card effect (current official text)Destroy the 1 face-up monster your opponent controls that has the lowest ATK (your choice, if tied).
Rulings
- You can activate Fissure even if your opponent only has 1 monster on the field.
- If there are two or more monsters with equal ATK on your opponent’s side of the field, you (the player who activated Fissure) select which monster will be destroyed.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.