A Command variant allows you to play a card not in your deck, for example a card in the Supply. Many are also Commands. Command variants provide extra flexibility and reliability to the deck: when you draw such a card, you get to choose from the effects of whichever other cards would be the most beneficial for you on this particular turn. Because of this flexibility, most Command variants restrict what you can play, such as by only playing cards from the Supply up to a certain cost. So if you need expensive cards, you'll have to buy them straight out. Emptying a Supply pile can severely weaken Command variants because there's one less card they can copy.
 List of Command variants
- Band of Misfits—plays a card in the Supply costing less, normally up to :
- Prince—plays a set-aside card costing up to that you first had to collide with Prince, every turn for the rest of the game :
- /: Estates under the influence of Inheritance—plays a card costing up to set aside from the supply when you bought Inheritance
- Overlord—plays a card in the Supply costing up to :
- Necromancer—plays a card in the trash :
- Captain—plays two cards in the Supply costing up to :
Way of the Mouse's ability mechanically resembles a Command variant, in that its effect is to play a set-aside card, "leaving it there", but unlike a proper Command variant it does not allow the player to choose during the game what that card is.
 Tracking Rules
- Some cards can play a card that isn't put into play.
- When you play one of these cards, leave it in play as long as you would have left the card it plays in play. So if Overlord plays a Wharf, Overlord will stay in play, and if Overlord plays a Throne Room that plays a Wharf, Overlord will also stay in play.
- If it plays multiple Duration cards (e.g., you used Throne Room on it), leave it out until the Clean-up of the last turn that one of them still had effects.
- If you Throne an Overlord, and the Overlord plays a Wharf, the Throne Room will not stay in play.
 Rules complications with Command variants
Early Command variants—prior versions of Band of Misfits, Inheritance, and Overlord—acted by actually changing the identity or abilities of the played card. Thus when you played a Band of Misfits, for example, it "became" a copy of whatever card it was playing as until it left play, and was counted as such for the purposes of such cards as Horn of Plenty. Donald X. had expressed dissatisfaction with this state of affairs because it involved "shapeshifting": two copies of the same card in different locations (e.g., a Band of Misfits in play and one in the trash, or an Estate in your deck and one in an opponent's deck) might have different names, types, and/or abilities. This led to the Dominion 2019 Errata and Rules Tweaks that altered these to work like the later Command variants.
The later Command variants (Necromancer and Captain) work in a different way: technically, instead of "becoming" the target card, they just cause the target card to be played without entering the play area (i.e., "leaving it there"). Certain of these cards are not allowed to play Duration cards, to avoid confusion caused by Duration cards being played with nothing left in play to track them. New tracking rules were added to allow some of these later-style Command variants to track Duration cards (either playing them or playing a card that plays them multiple times).
Later Command variants are more effective at playing one-shots than earlier ones: if you play an Experiment with Captain nothing returns to the Supply, whereas pre-errata versions of Band of Misfits that played an Experiment would. On the other hand, earlier Command variants were more effective with cards that have a "when you discard this from play" ability, like Herbalist (prior version); with later Command variants, the played card is never put into play, so those abilities are never triggered. For these reasons, certain one-shots were given errata to have some of their effects contingent on trashing.
The Command type was added to certain cards (Band of Misfits, Overlord, Captain itself, Prince and Inheritance) to prevent strange loops that could happen if they could (or were forced to) play each other.
 Why aren't Estate and Necromancer Command cards?
 Further thoughts from Donald X.