CR 611.2b tells us that continuous effects with “for as long as ~ remains tapped” (e. g. Amber Prison, Vedalken Shackles) won't do anything “if the ‘for as long as’ duration never starts, or it ends before the moment the effect would first be applied”.

What if I pay {4} and tap my Amber Prison targeting creature A, then untap the artifact (e. g. with Voltaic Key) before the ability resolves, and then pay {4} and tap Amber Prison again targeting creature B? I'd say that both creatures don't untap during their controllers' untap step, because when either of the activated abilities resolves, it sees a tapped Amber Prison, so the continuous effect is created and applies to creature A or B, respectively. The continuous effect shouldn't care about what happened before, it just should check at the very moment it is created, i. e. when the ability resolves.

Whether or not my guess is right, CR 611.2b should express this more accurately.

Mario Haßler

Creature A will untap like normal, Creature B will not. 611.2b the rule that applies, as you already alluded to:

611.2b Some continuous effects generated by the resolution of a spell or ability have durations worded “for as long as . . . .” If the “for as long as” duration never starts, or it ends before the moment the effect would first be applied, the effect does nothing. It doesn’t start and immediately stop again, and it doesn’t last forever.

The creature remains tapped “as long as Amber Prison remains tapped”. Since the Prison became untapped before its ability resolves, the duration ended before it could begin, so that part of the effect won't do anything. So Creature A will become tapped, but it will untap like normal during its controller's untap step. It does not matter that the Prison became tapped again before the ability resolves, what matters is that it became untapped before the effect first applied, so the Prison will not prevent it from untapping.

Nathan Long
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