For every card attached to the opposing champion, the opponent must roll a d10. If the number rolled is even, the attached card is discarded. (Off 4)
Copyrights:
TSR
Wizards of the Coast
The Entropy Shield is an interesting wizard spell. It provides no icon bonus, and is very unstable, possibly not doing anything in the round of combat. However, there is a 50% chance that any card played after it will be discarded without ever activating.
Rigged Dice (22/MI) can be used to guarantee a specific card dies, but that should only be used if the opponent plays a card that would end the battle immediately. Because the power only activates for cards played after Entropy Shield, any battle you don't expect to win outright with the first card should start with your spellcaster casting it.
No other card could be as effective as Entropy Shield, but Entropy Shield also has the same chance as being totally worthless.
I wouldn't expect to to see Entropy Shield in most tournament quality decks, but it could be very common in fun decks. If you love to gamble, this is a great card. Otherwise, pass on it and find something dependable.