Sifter is a broad term that applies to two types of cards:
- Deck inspectors that allow you to discard cards from the top of your deck
- Cards that draw and force you to discard, or allow you to discard in order to draw
Both are useful for cycling through your deck to get to more desirable cards. Many of these are non-terminal Actions, such as Warehouse. Sifters can increase or decrease handsize, depending on what additional role they take, if any. Some draw-to-X effects are also sifters because they make you discard your hand before drawing.
Card that do something other than drawing cards as compensation for (usually optional) discarding are discard for benefit cards. Cards that reveal (and eventually discard) cards while looking for specific other cards are digging cards.
 List of sifters
Cards in italics have been removed.
 Deck Sifters
Most of these are also deck inspectors.
- Scrying Pool
- Crystal Ball
- Cartographer - Top 4 cards
- Wandering Minstrel - forces discarding of non-Action cards
- Night Watchman
- Zombie Spy
- Scouting Party
- The Sun's Gift
- Forest Dwellers
- Order of Masons - sifts when you shuffle.
 Deck Sifters that are not Deck inspectors
These allow you to sift through your deck, but do not allow you to put cards back:
 Hand Sifters
These cards draw cards then discard, or vice versa.
- Diplomat - sifts as its Reaction effect (using the Reaction does not use up an Action)
- Secret Passage - puts a card back in your deck, rather than discarding
- Stables - Only lets you discard Treasure cards
- Old Map
- Capital City
- Sea Witch
- Young Witch
- Witch's Hut
- Royal Blacksmith - Only discards Coppers, but discards all of them
Some draw-to-X effects are also sifters because they make you discard your hand before drawing.
Sifters, particularly those that give +1 Action, are most useful in trying to get two combo-ing cards to collide. The most extreme case is Treasure Map, but there are other cards that do best in combination with another card. Sifters are optimal for this because they usually draw more than terminal draw cards at the same cost, giving you more cards that could be what you're looking for, and since you're only looking for two cards, you don't care that you have to discard afterwards. All sifters are also quite nice with Tunnel, as they provide the much-needed discard outside of the Clean-up phase to gain Tunnel's Golds.
Sifters which maintain or increase handsize and sifters which draw-then-discard are much more flexible than those which discard first or shrink the player's hand. For example, a single copy of Cellar can provide great value to an engine, but a hand with two cellars forces an awkward choice. On the other hand drawing two copies of Forum is almost strictly better than drawing one, since they require no guesswork and can be chained in any number. Discard-first and hand-shrinking sifters can add consistency to an engine but rarely enable one, while cards like Forum can enable engines even in the absence of Village or Library effects.
Terminal sifters are usually more useful in the context of an engine, or in big money strategies. Without village support, they are highly likely to draw Actions dead, given their higher draw, though this is mitigated by their discarding requirement. This makes them very useful for big money, as they can concentrate your Treasures in hand while skipping over Victory cards. Terminal sifters are especially improved by on-demand +Actions like Villagers and Coin of the Realm, since these effects allow you to sift for villages rather than having them in your starting hand.
 Deck Sifters
 Hand sifters
 Draw-to-X sifters