Showstopping Surprise — ruling 1

If the target creature is a face-down creature that can’t be turned face up for any reason, it will remain face down on the battlefield and still deal damage equal to its power (which is very likely to be 2) to each other creature.

Showstopping Surprise : règles, fonctionnement et interactions (MTG)

Showstopping Surprise is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Choose target creature you control. Turn it face up if it's face down. Then it deals damage equal to its power to each other creature.

How it works : Showstopping Surprise

Original English text — Wizards of the Coast / Scryfall

#1February 2, 2024· Wizards of the Coast
If the target creature is a face-down creature that can’t be turned face up for any reason, it will remain face down on the battlefield and still deal damage equal to its power (which is very likely to be 2) to each other creature.
No other card is named in this ruling.