Vigil for the Lost — ruling 1

As the ability resolves, you choose a value for X and decide whether to pay {X}. If you do decide to pay {X}, it’s too late for any player to respond since the ability is already in the midst of resolving.

Vigil for the Lost : règles, fonctionnement et interactions (MTG)

Vigil for the Lost 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

Whenever a creature you control dies, you may pay . If you do, you gain X life.

How it works : Vigil for the Lost

Original English text — Wizards of the Coast / Scryfall

#1January 1, 2011· Wizards of the Coast
As the ability resolves, you choose a value for X and decide whether to pay . If you do decide to pay , it’s too late for any player to respond since the ability is already in the midst of resolving.
No other card is named in this ruling.