"After years of study, I've learned an important lesson: the relics we watch may be watching us back."
—Anowon, the Ruin Sage

Amulet of Vigor

Whenever a permanent you control enters tapped, untap it.

"Everyone is obsessed with this cosmium stuff, but I can sense some kind of comparable power in this droplet of ancient amber."
—Quintorius Kand, research notes

The Lost Caverns of Ixalan Commander

Whenever a permanent enters the battlefield tapped and under your control, untap it.

"Angels guide me while I wake,
and I will watch for evil's creep.
Angels guard me while I dream,
and I will rest in peaceful sleep."
—Amulet inscription

Secret Lair Drop

The List

Worldwake

For Amulet of Vigor's ability to trigger, a permanent must enter tapped due to an effect that says "put [the permanent] onto the battlefield tapped," "[this permanent] enters tapped," or the like. If it enters untapped, the ability won't trigger, even if you tap that permanent afterward.

If you control more than one Amulet of Vigor, each Amulet's ability triggers when a permanent enters tapped and under your control. The first ability that resolves will untap that permanent. If the permanent somehow becomes tapped again before the next ability resolves, the next ability will untap it as well (and so on).