Oracle en-Vec — ruling 1

The way the card works is that the target player chooses which creatures will attack on their next turn. Creatures which are chosen to attack, but do not attack, are destroyed at the end of that turn. Creatures which are not chosen to be attackers are not affected in any way other than being unable to attack.

Oracle en-Vec : règles, fonctionnement et interactions (MTG)

Oracle en-Vec 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

: Target opponent chooses any number of creatures they control. During that player's next turn, the chosen creatures attack if able, and other creatures can't attack. At the beginning of that turn's end step, destroy each of the chosen creatures that didn't attack this turn. Activate only during your turn.

How it works : Oracle en-Vec

Original English text — Wizards of the Coast / Scryfall

#1October 4, 2004· Wizards of the Coast
The way the card works is that the target player chooses which creatures will attack on their next turn. Creatures which are chosen to attack, but do not attack, are destroyed at the end of that turn. Creatures which are not chosen to be attackers are not affected in any way other than being unable to attack.
No other card is named in this ruling.