Cheapest priced copy (Planeshift): $0.49 at Card Kingdom, near mint, their price list as of .
Planeswalker's Mischief 
Enchantment · Rare · Planeshift · #29
{3}{U}: Target opponent reveals a card at random from their hand. If it's an instant or sorcery card, exile it. You may cast it without paying its mana cost for as long as it remains exiled. At the beginning of the next end step, if you haven't cast it, return it to its owner's hand. Activate only as a sorcery.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.49 to $9.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Planeshift | 29 | Rare | $0.49 | $9.99 |
| The List | PLS-29 | Rare | — | — |
3 rulings from Wizards of the Coast
- 4 October 2004If Planeswalker’s Mischief leaves the battlefield, any cards it exiled are still under the effect of the ability and can be cast (and if they are not cast, they are returned to the owner’s hand).
- 4 October 2004When cast, the card goes to its owner’s graveyard after it resolves.
- 4 October 2004If the opponent has no cards in hand, then the ability does nothing.