Mudslide [Ice Age] Rare players can't untap more than

players can't untap more than one land during their untap steps

If you do and they guessed wrong

{T}: Prevent all damage that would be dealt to you this turn by attacking creatures without flying

Set: Unlimited Edition Type: Creature — Troll Rarity: Rare Cost: {2}{R} Sedge Troll gets +1/+1 as long as you control a Swamp

Mishra also mastered the intricacies of artifice

Mudslide [Ice Age] Rare players can't untap more thanSet: Ice Age Type: Enchantment Rarity: Rare Cost: {2}{R} Creatures without flying don't untap during their controllers' untap steps. At the beginning of each player's upkeep, that player may choose any number of tapped creatures without flying they control and pay {2} for each creature chosen this way. If the player does, untap those creatures.