Underdome

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to pay Un-costs.

Very Cryptic Command

Choose two —
• Switch target creature's power and toughness until end of turn.
• Target creature can't be blocked this turn.
• Draw a card. If that card's art is by Wayne England, you may reveal it and draw another card.
• Assemble a Contraption.

Steamflogger Service Rep

Whenever another Goblin you control enters, you may pay {1}. If you do, this creature assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Midlife Upgrade

As an additional cost to cast this spell, sacrifice X Contraptions.
Assemble X plus one Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Nearby Planet

Rangeling (This card is every land type, including Plains, Island, Swamp, Mountain, Forest, Desert, Gate, Lair, Locus, and all those Urza's ones.)
This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.

Chipper Chopper

Flying
When this creature enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on this creature and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Cogmentor

Flying
{4}: Reassemble target Contraption you control. (Move it onto another one of your sprockets.)

Steamflogger Temp

{6}, {T}: This creature assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Joyride Rigger

When this creature enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Steamflogger Boss

Other Riggers you control get +1/+0 and have haste.
If a Rigger you control would assemble a Contraption, it assembles two Contraptions instead.

Incite Insight

Assemble X Contraptions. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Overt Operative

Menace
Whenever this creature deals combat damage to a player, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Riveting Rigger

When this creature enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on this creature and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Contraption Cannon

{2}, Sacrifice this artifact: It deals damage to any target equal to the number of Contraptions you control.

Vorthos, Steward of Myth

As Vorthos, Steward of Myth enters, choose a named Magic character.
Each spell you cast with the chosen character in its name, flavor text, or art costs {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.

The Big Top

{T}: Add one mana of any color that appears on your top. (A top is an outerwear garment worn on the upper body.)

Steamflogger of the Month

When this creature enters, it assembles a Contraption for each Contraption you control. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

City of Ass

This land enters tapped.
{T}: Add one and one-half mana of any one color.

Finders, Keepers

Destroy target creature, then assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

R&D's Secret Lair

Play cards as written. Ignore all errata.
{T}: Add {C}. (This mana is still added to your mana pool.)

Steamfloggery

Roll a six-sided die. Assemble a number of Contraptions equal to the result. (To assemble a Contraption, put the top card of your Contraption deck face up onto one of your sprockets.)

Kindly Cognician

Spells you cast that refer to artifacts or Contraptions in their rules text cost {1} less to cast.

Spell Suck

Counter target spell, then assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Crafty Octopus

When this creature enters, this creature assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Garbage Elemental

When this creature enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Watermarket

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

Wrench-Rigger

Aerial Toastmaster

Flying
{3}{W}, Sacrifice another artifact: This creature assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Suspicious Nanny

Whenever this creature deals combat damage to a player, it reassembles target Contraption that player controls. (Gain control of it and move it onto one of your sprockets.)

Jackknight

Whenever another artifact you control enters, put a +1/+1 counter on this creature. If that artifact is a Contraption, this creature gains lifelink until end of turn.

First Pick

Destroy target artifact or enchantment. Assemble a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Clock of DOOOOOOOOOOOOM!

{4}, {T}: Move the CRANK! counter to your Contraption deck's next sprocket and crank any number of that sprocket's Contraptions.

Urza's Fun House

{T}: Add {C}.
{T}: Add {∞}. Activate only once and only if you control an Urza's Mine, an Urza's Power-Plant, and an Urza's Tower.
{7}, {T}: Head to AskUrza.com and click this land.

Secret Base

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with this land.

Steady-Handed Mook

Deathtouch
When this creature enters, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

Work a Double

Assemble two Contraptions. (Put the top card of your Contraption deck face up onto one of your sprockets. Then repeat this process.)