Strength-Testing Hammer

Whenever equipped creature attacks, roll a six-sided die. That creature gets +X/+0 until end of turn, where X is the result. Then if it has the greatest power or is tied for greatest power among creatures on the battlefield, draw a card.
Equip {3}

Grand Marshal Macie

You may choose not to untap Grand Marshal Macie during your untap step. If you do, put a pause counter on it, then you lose 1 life for each pause counter on it.
Whenever Macie becomes untapped, remove all pause counters from it.
{2}, {T}: Choose an "until end of turn" or "this turn" effect. As long as Macie remains tapped, that effect doesn't end.

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 Urza's Fun House.

Exchange of Words

When Exchange of Words enters, choose two target creatures. For as long as Exchange of Words remains on the battlefield, exchange the text boxes of those creatures.

Comet, Stellar Pup

0: Roll a six-sided die.
1 or 2 — [+2], then create two 1/1 green Squirrel creature tokens. They gain haste until end of turn.
3 — [−1], then return a card with mana value 2 or less from your graveyard to your hand.
4 or 5 — Comet, Stellar Pup deals damage equal to the number of loyalty counters on him to a creature or player, then [−2].
6 — [+1], and you may activate Comet, Stellar Pup's loyalty ability two more times this turn.

Standard Procedure

{1}, Reveal Standard Procedure from your hand: Choose an instant or sorcery card with mana value 3 or less currently legal in the Standard format. Standard Procedure becomes that card until end of turn.

Opening Ceremony

Add {W}{U}{B}{R}{G}{C}. You may open a sealed Magic booster pack. Until end of turn, you may cast spells from among the cards in that booster pack.

Trigger Happy

Choose a triggered ability of target permanent. It triggers. You control that ability.