Intruder Alarm
Enchantment{2}{U}
Creatures don't untap during their controllers' untap steps. Whenever a creature enters, untap all creatures.
Colour identity Blue
In short
Intruder Alarm has 6 listed printings; the most valuable is the Secret Lair printing from SLD at US$12.89 on TCGplayer's market price. Prices below are the cheapest in-stock listing in the United States.
Every Intruder Alarm printing
Secret Lair
Intruder Alarm
SLD · 229
TCGplayer market
US$12.89
Intruder Alarm
STH · 34
TCGplayer market
US$6.55
The List
Intruder Alarm
PLST · 8ED-86
TCGplayer market
US$5.94
Intruder Alarm
8ED · 86
TCGplayer market
US$5.87
Borderless
Intruder Alarm
TLE · 15
TCGplayer market
US$4.20
Borderless
Intruder Alarm
WOT · 21
TCGplayer market
US$3.87