From DominionStrategy Wiki
You may play an Avanto from your hand.
While this is in play, when you play a Silver, you may trash a card from your hand.
 Official FAQ
- When you play Sauna, you first draw a card and get +1 Action.
- You may then immediately play an Avanto from your hand. This does not take up one of your actions, including the action provided by Sauna.
- You can only play an Avanto this way directly after playing the Sauna, not if you played another action card in between, even if you have a Sauna in play.
- When you play Avanto, you first draw 3 cards.
- You may then immediately play a Sauna from your hand. This does not take up any of your actions, and Sauna will still give you +1 Action if you play it this way.
- You can only play a Sauna this way directly after playing the Avanto, not if you played another action card in between, even if you have an Avanto in play.
- You can play Sauna and Avanto in alteration this way, taking up only the action for the first of the cards you play.
- You can do this until you don't have the respective card in hand after playing the other.
- When you play a Sauna, you cannot immediately play a Sauna from your hand without using up one action. The same goes for playing Avanto after Avanto.
- While Sauna is in play, you can trash a card from your hand anytime you play a Silver.
- If you play the same Silver several times, such as with Counterfeit (Dominion - Dark Ages) or Crown (Dominion - Empires), you may trash a card each time you play the Silver.
- You do not have to trash anything when you play a Silver.
- You can decide to trash a card every time you play a Silver, you do not have to decide once for the entire turn.
- When Sauna leaves play, such as being trashed with Procession (Dominion - Dark Ages), you cannot use its effect anymore.
- When you have several Saunas in play and play a Silver, you can trash a card from your hand for every Sauna you have in play. You can still decide to not trash a card each time.
 Alternate versions
 In other languages
- German: Sauna
- Japanese: サウナ (pron. sauna)
- Polish: Sauna
- Russian: Сауна (pron. sauna)
 Secret History