Is it illegal to have multiple copies of nullify (face down) on my mage?

[phillipsjr2]

I know that revealed enchantments you destroy a second copy, but is this true of face-down enchantments such as nullify that would be used once and then discarded?

[sIKE]

It is not illegal to have multiple copies, however, you would have to reveal all of them when the trigger mechanism is met. You could chose to pay the reveal cost of one, all, or none. Your choice....

[Kroko]

It is illegal. You can't have more card withe the same name on your mage/creature. So you can't cast four Nullifys on your mage. If you use one then you can cast another.

[DarthDadaD20]

Kroko is correct.

From the rules-

There is no limit to the number of different enchantments
that can be on an object, but each object or zone cannot
have more than one enchantment with the same name
attached to it at one time. This includes both hidden and
revealed enchantments. For example, you cannot attach two
Bear Strength spells to the same creature.

[Shad0w]

Yes it looks at both face up and face down enchants

[piousflea]

It's illegal to knowingly place a duplicate enchantment. It is possible to accidentally place a duplicate enchantment.

It is  theoretically possible that both players could put the same face-down card on the same creature. For example, two opposing Priest/Priestesses could place Divine Intervention on the same creature. (one player intending to use it defensively, the other intending to use it offensively) This is legal because there's no way you'd know that your opponent played the same card as you did.

[DarthDadaD20]

^ and once one is revealed the other is destoyed.

I didnt go into that as to prevent information overload!