Artifact Ward

Enchant creature
Enchanted creature can't be blocked by artifact creatures.
Prevent all damage that would be dealt to enchanted creature by artifact sources.
Enchanted creature can't be the target of abilities from artifact sources.

Priest of Yawgmoth

{T}, Sacrifice an artifact: Add an amount of {B} equal to the sacrificed artifact's mana value.

Mishra's Workshop

{T}: Add {C}{C}{C}. Spend this mana only to cast artifact spells.

Dragon Engine

{2}: Dragon Engine gets +1/+0 until end of turn.

Orcish Mechanics

{T}, Sacrifice an artifact: Orcish Mechanics deals 2 damage to any target.

Gaea's Avenger

Gaea's Avenger's power and toughness are each equal to 1 plus the number of artifacts your opponents control.

Artifact Possession

Enchant artifact
Whenever enchanted artifact becomes tapped or a player activates an ability of enchanted artifact without {T} in its activation cost, Artifact Possession deals 2 damage to that artifact's controller.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Reverse Polarity

You gain X life, where X is twice the damage dealt to you so far this turn by artifacts.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Argivian Blacksmith

{T}: Prevent the next 2 damage that would be dealt to target artifact creature this turn.

Transmute Artifact

Sacrifice an artifact. If you do, search your library for an artifact card. If that card's mana value is less than or equal to the sacrificed artifact's mana value, put it onto the battlefield. If it's greater, you may pay {X}, where X is the difference. If you do, put it onto the battlefield. If you don't, put it into its owner's graveyard. Then shuffle.

Reconstruction

Return target artifact card from your graveyard to your hand.

Tablet of Epityr

Whenever an artifact you control is put into a graveyard from the battlefield, you may pay {1}. If you do, you gain 1 life.

Rocket Launcher

{2}: Rocket Launcher deals 1 damage to any target. Destroy Rocket Launcher at the beginning of the next end step. Activate only if you've controlled Rocket Launcher continuously since the beginning of your most recent turn.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Urza's Chalice

Whenever a player casts an artifact spell, you may pay {1}. If you do, you gain 1 life.

Coral Helm

{3}, Discard a card at random: Target creature gets +2/+2 until end of turn.

Tawnos's Wand

{2}, {T}: Target creature with power 2 or less can't be blocked this turn.

Phyrexian Gremlins

You may choose not to untap Phyrexian Gremlins during your untap step.
{T}: Tap target artifact. It doesn't untap during its controller's untap step for as long as Phyrexian Gremlins remains tapped.

Rakalite

{2}: Prevent the next 1 damage that would be dealt to any target this turn. Return Rakalite to its owner's hand at the beginning of the next end step.

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.

Argothian Pixies

Argothian Pixies can't be blocked by artifact creatures.
Prevent all damage that would be dealt to Argothian Pixies by artifact creatures.

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Grapeshot Catapult

{T}: Grapeshot Catapult deals 1 damage to target creature with flying.

Amulet of Kroog

{2}, {T}: Prevent the next 1 damage that would be dealt to any target this turn.

Clay Statue

Colossus of Sardia

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Colossus of Sardia doesn't untap during your untap step.
{9}: Untap Colossus of Sardia. Activate only during your upkeep.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Battering Ram

At the beginning of combat on your turn, Battering Ram gains banding until end of combat. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's blocking.)
Whenever Battering Ram becomes blocked by a Wall, destroy that Wall at end of combat.

Crumble

Destroy target artifact. It can't be regenerated. That artifact's controller gains life equal to its mana value.

Power Artifact

Enchant artifact
Enchanted artifact's activated abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.