Filter land

Filter lands can refer to two different sets of dual lands. Their name describes the ability to take one mana and turn it into a combination of two colored mana.

Odyssey filter lands
The original filter lands were a cycle of lands that appeared in Odyssey. They each have an activation cost of and produce two mana of different colors of an allied color pair.
 * Skycloud Expanse
 * Darkwater Catacombs
 * Shadowblood Ridge
 * Mossfire Valley
 * Sungrass Prairie

Shadowmoor/Eventide filter lands
Newer filter lands were previewed in Future Sight. The cycle of ten dual lands was finished in the sets Shadowmoor and Eventide. In Shadowmoor the cycle of allied colored lands were printed, while Eventide had the cycle of enemy colored lands. They each take one mana of two possible colors and produce two mana of any combination of the two colors that can be paid. They can also tap for mana. They were reprinted in Oath of the Gatewatch: Zendikar Expeditions and Double Masters


 * Future Sight Timeshifted Shadowmoor preview
 * Graven Cairns

Allied colored from Shadowmoor

 * Mystic Gate
 * Sunken Ruins
 * Graven Cairns</c>
 * Fire-Lit Thicket</c>
 * Wooded Bastion</c>

Enemy colored from Eventide

 * Fetid Heath</c>
 * Cascade Bluffs</c>
 * Twilight Mire</c>
 * Rugged Prairie</c>
 * Flooded Grove</c>

Ravnica Signets
During Ravnica block a cycle of ten Mana Stones were printed which have abilities similar to the original filter lands. These artifacts cost to cast and can be tapped to filter  into two mana of two different colors.

Allied colored

 * Azorius Signet</c>
 * Dimir Signet</c>
 * Rakdos Signet</c>
 * Gruul Signet</c>
 * Selesnya Signet</c>

Enemy colored

 * Orzhov Signet</c>
 * Izzet Signet</c>
 * Golgari Signet</c>
 * <c>Boros Signet</c>
 * <c>Simic Signet</c>

Original triple lands
The earliest triple land cycle from Homelands which produces three colors of mana conditionally as follows:
 * undefined: Add.
 * ,undefined: Add M.
 * ,undefined: Add N or O.

where N and O are the allied colors of M.


 * <c>Aysen Abbey</c>
 * <c>Wizards' School</c>
 * <c>Castle Sengir</c>
 * <c>Koskun Keep</c>
 * <c>An-Havva Township</c>

By a looser definition, much like some of the lands listed below, these too are filter lands, but are strictly worse than several of them.

Other filter lands
There are a few other filter lands, that don't belong in any cycle:
 * <c>Cabal Coffers</c> from Torment Adds  for each Swamp you control for.
 * <c>Crystal Quarry</c> from Odyssey Adds  for.
 * <c>Henge of Ramos</c> from Mercadian Masques Adds one mana of any color for.
 * <c>School of the Unseen</c> from Alliances Adds one mana of any color for.
 * <c>Shimmering Grotto</c> from Lorwyn Adds one mana of any color for.
 * <c>Unknown Shores</c> from Theros Adds one mana of any color for.
 * <c>Painted Bluffs</c> from Amonkhet Adds one mana of any color for.
 * <c>Cascading Cataracts</c> from Amonkhet Adds five mana in any combination of colors for.
 * <c>Cabal Stronghold</c> from Dominaria Adds  for each basic Swamp you control for.
 * <c>Cave of Temptation</c> from Modern Horizons Adds one mana of any color for.
 * <c>Crypt of the Eternals</c> from Hour of Devastation Adds, , or  for.

<c>Castle Garenbrig</c> is an unusual case, as it belongs to a cycle in Throne of Eldraine, but the others do different effects. It filters into six  for creature abilities or spells.