Armory Guard — ruling 1

Vigilance only matters when Armory Guard is being declared as an attacking creature. If Armory Guard is already attacking, losing control of your only Gate won’t cause Armory Guard to become tapped or to leave combat.

Armory Guard : règles, fonctionnement et interactions (MTG)

Armory Guard 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

This creature has vigilance as long as you control a Gate.

How it works : Armory Guard

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2012· Wizards of the Coast
Vigilance only matters when Armory Guard is being declared as an attacking creature. If Armory Guard is already attacking, losing control of your only Gate won’t cause Armory Guard to become tapped or to leave combat.
No other card is named in this ruling.