Disarmament

[clustro]

Disarmament
Enchantment
Creatures with +1/+1 counters on them can't attack you unless their controller removes those counters.
Equipped creatures can't attack you unless their controller detaches their Equipment.

"No blades. No bows. Leave your weapons here."

[Xyx]

Feels more like a white effect.

[Magus Jr]

Feels more like a white effect.

Indeed. Also, players can't really just willfully Remove counters. Takes cards that no one runs to do that.

[Xyx]

Well, you can't willfully pay mana when attacking with creatures either. Takes a Ghostly Prison to do that.

[guyarney]

Possible wording?:

Each creature with a +1/+1 counter on it can't attack you unless its controller removes a +1/+1 counter from each of those creatures he or she controls that's attacking you.