Rule 822.1
Ambush is a Passive Ability keyword.
- 822.1.a It is normally present on Units.
- 822.1.b It is functionally short for "I may be played to a battlefield where you control Units" and “I have [Reaction] as long…
- 822.1.c It is a passive ability that adds options to locations that are valid for a Unit to be played to during the Make…
- 822.1.d Ambush can also appear as a verb on a card. In such a case, the verb is taken to mean “play with the permissions of…