Urza's Tower

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

Scepter of Empires

{T}: This artifact deals 1 damage to target player or planeswalker. It deals 3 damage instead if you control artifacts named Crown of Empires and Throne of Empires.

Trophy Mage

When this creature enters, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Trinket Mage

When this creature enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Tinker

As an additional cost to cast this spell, sacrifice an artifact.
Search your library for an artifact card, put that card onto the battlefield, then shuffle.

Urza's Mine

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

Throne of Empires

{1}, {T}: Create a 1/1 white Soldier creature token. Create five of those tokens instead if you control artifacts named Crown of Empires and Scepter of Empires.

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 Cave

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Crown of Empires

{3}, {T}: Tap target creature. Gain control of that creature instead if you control artifacts named Scepter of Empires and Throne of Empires.

Staff of Nin

At the beginning of your upkeep, draw a card.
{T}: This artifact deals 1 damage to any target.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Tribute Mage

When this creature enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Mazemind Tome

{T}, Put a page counter on this artifact: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{2}, {T}, Put a page counter on this artifact: Draw a card.
When there are four or more page counters on this artifact, exile it. If you do, you gain 4 life.