When an effect resolves that was activated by your opponent's Effect Monster on the field, they can discard 1 card. If they do not, that effect is negated.
NM-Mint 1st Edition - $2.70
NM-Mint 1st Edition Non English - $2.70
Lightly Played 1st Edition - $2.60
Lightly Played 1st Edition Non English - $2.60
Moderately Played 1st Edition - $2.40
Moderately Played 1st Edition Non English - $2.40
Heavily Played 1st Edition - $2.20
Heavily Played 1st Edition Non English - $2.20
Damaged 1st Edition - $1.80
Damaged 1st Edition Non English - $1.80