If I damage a unit before casting Imperial Decree, does it still die, or do I have to deal damage after casting Imperial Decree?

Ruling: Imperial Decree only kills units that take damage after it resolves. Units that were damaged before you cast Imperial Decree will not be killed by it, even if they are still damaged.

Sequence:

• Cast Imperial Decree
• Imperial Decree resolves and creates a triggered ability for the remainder of the turn
• When any unit takes damage while this effect is active, the trigger fires and kills that unit

Nuances:

• "Takes damage" refers to the event of receiving damage, not the state of being damaged
• Imperial Decree does not look back in time to kill units that were previously damaged
• Reducing a unit's Might (such as with counters) is not the same as dealing damage and will not trigger Imperial Decree