Bond of Discipline — ruling 1

You can cast Bond of Discipline even if your opponents control no creatures or you control no creatures. The creatures that are on the battlefield will be affected as appropriate.

Bond of Discipline : règles, fonctionnement et interactions (MTG)

Bond of Discipline 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

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

How it works : Bond of Discipline

Original English text — Wizards of the Coast / Scryfall

#1May 3, 2019· Wizards of the Coast
You can cast Bond of Discipline even if your opponents control no creatures or you control no creatures. The creatures that are on the battlefield will be affected as appropriate.
No other card is named in this ruling.