If your discard pile has any cards in it: +1 Coffers, then if you have at least 4 Coffers tokens, take the Treasure Chest.
Swashbuckler is an Action card from Renaissance. It is terminal draw that gets you Coffers and, if you save up the Coffers instead of spending them, will eventually get you its corresponding Artifact, the Treasure Chest. Getting the Coffers and the Treasure Chest are contingent upon having a discard pile; for example if the draw from Swashbuckler causes you to reshuffle, you will get no additional effect from Swashbuckler. Cards that let you discard and other players playing junkers can help you get a discard pile to activate Swashbuckler.
 Official FAQ
- First you draw 3 cards, then you check to see if your discard pile has any cards in it; if drawing those cards caused you to shuffle, your discard pile would be empty.
- If your discard pile has at least one card, you get +1 Coffers, and if you then have 4 or more tokens on your Coffers, you take the Treasure Chest.
- You cannot get the Treasure Chest unless your discard pile had at least one card.
- Plaza. It's a Village, which helps make the terminal draw useful. It discards cards, which helps activate the extra functionality. And it can produce Coffers, which helps get the Treasure Chest if you want it.
- Inn. In addition to being a village that discards, its on-gain effect can move cards from the discard into your deck, which helps prevent the depletion that (after Swashbuckler draws 3 cards) triggers a reshuffle, losing the discard pile entirely. Similarly, Herald is a non-terminal discarder whose on-gain effect (with overpayment) restocks your deck from your discard, and Annex is especially good for deck replenishment.
Swashbuckler is a prime Terminal draw Big Money card: a Smithy with the added possibility of coffers and an even more tantalizing prospect -- money doesn't get bigger than a guaranteed Gold every turn. However, its relationship with other conventional aspects of the Big Money strategy is finnicky. Drawing too many cards with non-Swashbucklers can eat up the discard pile (by reshuffling) before Swashbuckler has the chance to observe it. For similar reasons, it also doesn't work well with the Engine approach, especially deck-thinning.
 English versions
|+3 Cards. If your discard pile has any cards in it: +1 Coffers, then if you have at least 4 Coffers tokens, take the Treasure Chest.||Renaissance||November 2018|
 Other language versions
|Chinese||劍客 (pron. jiànkè, lit. swordsman)|
|French||Bretteuse (Note: explicitly feminine)||+3 Cartes Si votre défausse n'est pas vide : +1 Coffres, puis si vous avez au moins 4 jetons sur vos Coffres, prenez le Coffre au trésor.|
|German||Freibeuterin (lit. privateer, explicitly feminine)|
|Japanese||剣士 (pron. kenshi, lit. swordsman)||+3 カードを引く。 捨て札置き場にカードがある場合:+1 コイントークン、4枚以上コイントークンを所持している場合、宝箱を得る。|
|Russian||Головорез (pron. golovoryez)|
 Secret History