Filter artifact

Filter artifacts, like filter lands, allow players to exchange incorrectly colored or colorless mana into a color of their choosing.

Description

Common artifact mana was often weak as fixing for many years before Ravnica: City of Guilds, which produced some of the strongest fixing in the Signet cycle, 2-mana artifacts which filtered into a color pair. However, this meant that nongreen decks had a consistent colored ramp, which undercut green's ramping spells, as Rampant Growth was already quite strong. Five-color mana stones eventually got their average rate at three mana, giving space for weaker fixing at two and one, which is where filter artifacts reside.

These artifacts are often common in rarity and low in power and mana cost, as they are not meant to be premium mana fixing; this can be achieved by either costing two mana to filter into one colored, requiring a tap or can only fix once through sacrificing. Unlike mana stones, these artifacts rarely generate mana on their own. However, they can provide other utility, such as being creatures or drawing a card.

Some are termed as "eggs", where sacrificing (or "cracking") them gives both mana and a card. As this can let them be cycled through easily, at mass they can become the cornerstone of certain combos, such as in Second Sunrise or Krark-Clan Ironworks combo.

List of filtering artifacts

Mana only

• Azorius Signet — Filters for , .
• Boros Signet — Filters for , .
• Celestial Prism — Filters for , .
• Dimir Signet — Filters for , .
• Gemstone Array — Filters for , remove a Charge counter.
• Golgari Signet — Filters for , .
• Gruul Signet — Filters for , .
• Izzet Signet — Filters for , .
• Mana Cylix — Filters for ,
• Mana Prism — Filters for , ; can also tap for .
• Orzhov Signet — Filters for , .
• Prismatic Lens — Filters for , ; can also tap for .
• Pyramid of the Pantheon — Filters for , ; taps for 3 mana once powered up
• Rakdos Signet — Filters for , .
• Selesnya Signet — Filters for , .
• Simic Signet — Filters for , .
• Standing Stones — Filters for , , and 1 life

Creatures

• Coal Golem — Filters into and sacrificing, is a 3/3
• Codie, Vociferous Codex — Filters into , tapping, and is a 1/4
• Crosis's Attendant — Filters and sacrifice into , is a 3/3
• Crossroads Candleguide — Filters for , is a 3/4, exiles a card in graveyard
• Darigaaz's Attendant — Filters and sacrifice into , is a 3/3
• Dromar's Attendant — Filters and sacrifice into , is a 3/3
• Gravestone Strider — Filters for once a turn, is a 1/3; can exile one card in a graveyard
• Pili-Pala — Filters for and untapping, is a 1/1
• Prismite — Filters for , is a 2/1
• Rith's Attendant — Filters and sacrifice into , is a 3/3
• Salvaged Manaworker — Filters for once a turn, is a 1/3
• Scarecrow Guide — Filters for once a turn, is a 2/1
• Shire Scarecrow — Filters for once a turn, is a 0/3
• Signpost Scarecrow — Filters for , is a 2/4
• Stonework Packbeast — Filters for , is a 2/1
• Treva's Attendant — Filters and sacrifice into , is a 3/3

Draws a card

• Arcum's Astrolabe — Filters for , ; draws as an entry ability, is and makes snow mana
• Energy Refractor — Filters for , draws as an entry ability
• Prophetic Prism — Filters for , ; draws as an entry ability 

Requires sacrifice (eggs)

• Astrolabe — Filters 2 for , draws on the next upkeep
• Barbed Sextant — Filters for , draws on the next upkeep
• Chromatic Sphere — Filters for , draws as a mana ability
• Darkwater Egg — Filters 2 mana into , draws as a mana ability
• Implements of Sacrifice Filters 2 mana for and sacrifice.
• Chromatic Star — Filters for , draws as a "dies" ability
• Golden Egg — Filters for , draws as an entry ability, is a Food
• Guild Globe — Filters 2 different mana for , draws as an entry ability
• Jack-o'-Lantern — Filters for , exile from your graveyard, draws as a "dies" ability
• Kaleidostone — Filters 5 mana into , draws as an entry ability
• Mossfire Egg — Filters 2 mana into , draws as a mana ability
• Shadowblood Egg — Filters 2 mana into , draws as a mana ability
• Skycloud Egg — Filters 2 mana into , draws as a mana ability
• Sungrass Egg — Filters 2 mana into , draws as a mana ability
• Terrarion — Filters 2 mana for , draws as a "dies" ability
• Wizard's Rockets — Filters X mana for , draws as a "dies" ability

Other

• Mox Lotus — Filters into 1 mana, taps for infinity, Acorn.
• Mystic Skull — Filters for , ; transforms to a 5/6 for
• North Star — Mana washing for , .
• Urn of Godfire — Filters for , destroys a creature or enchantment for and sacrifice