Set 2 Field Spells with different names from your Deck on the field (1 on your field, and 1 on your opponent's field). While either of those cards remain Set on the field, neither player can activate or Set other Field Spells.
Near Mint Unlimited - $5.40
Lightly Played Unlimited - $5.10
Moderately Played Unlimited - $4.50
Heavily Played Unlimited - $3.90
Damaged Unlimited - $3.00