Promotional cards are official Dominion kingdom cards and Events which do not belong to any particular set. They are a result of Donald X trying to meet the requests of his publishers, and typically either released to help promote Dominion at conventions (such as Origins or GenCon), or to commemorate the anniversary of another game, to help promote both.
 Card List
- Envoy (November 2008)
- Black Market (March 2009)
- Stash (February 2010)
- Walled Village (June 2011)
- Governor (October 2011)
- Prince (June 2014)
- Summon (November 2015)
- Sauna/Avanto (September 2016)
- Dismantle (December 2017)
- Church (August 2019)
- Captain (August 2019)
 Cards gallery
 Kingdom cards
 Impact of Promo Cards
The promotional cards range from simple, but balanced cards that there simply wasn't room for in a main set (Envoy and Walled Village), to being almost patently ridiculous in their mechanics. As such, Promo cards frequently feature in complicated engines or combos that hinge on their peculiar mechanic.
- Envoy - has a draw that rivals Smithy at the same cost
- Black Market - can give access to a key card that makes an engine or combo work that no other player will be able to get
- Walled Village - Villages are always useful, but this one ensures that it will be in a hand with other engine parts
- Governor - an engine unto itself at times
- Prince - ensures that a cheap component is played every turn, smoothing out your engine
- Sauna/Avanto - together act as both a trasher and a self-sufficient engine
- Summon - ensures that a cheap component is played immediately, without costing an Action
- Envoy - better than Smithy+BM
- Stash - four of these guarantees a Province every shuffle
- Governor - gains Gold, for a price
- Black Market - aside from the power of having the sole copy of a card, it can play Treasures during your Action phase, allowing for, e.g., playing Treasures before Tactician or draw-to-X.
Until the release of Summon, each Promo had its own unique expansion symbol, either referring to the convention it was distributed at, or the other game it was helping to promote. When Summon was released, Donald X felt there was a need for a generic Promo symbol, which ended up being a flag. All other Promos released since then have had that symbol, and all previous Promos were given that symbol as part of the second edition update.
Several Promo cards are "outtakes", or borrowed from a yet-to-be-released set. Governor was designed on the spot, borrowing a name and mechanic from the game Puerto Rico, and Summon was designed by a playtester after the release of Adventures. Further details on the design and history of the cards can be found on the individual card pages.
 Online-only promos
After this post, TGG has stated that they would be interested in implementing an online-only promo.
 Obtaining The Promo Cards
- The cards can typically be purchased on the BGG store.
- Occasionally, game stores or conventions will offer the Promotional cards in conjunction with a purchase.
- Various iterations of the Big Box have included one or more Promotional cards, Black Market was included in Special Edition, and Summon was bundled with pre-release orders of Adventures German version.
- Tournaments may offer Promo cards as prizes.