This article's content is accurate to the most recent public game version, 0.4.8d.
"[5 turns] Greatly boosts the party's DEF."
Cost: 6 MP
Source: Veronica - Unlocked if she has the highest affection at the time of the trip to Earth and subsequently accompanies Eric(a).
Dampening Field is a spell that gives two stages of DEF Up to all party members for five turns.
As per all long lasting party buffs it is helpful in prolonged fights, especially against enemies with strong physical attacks. Dampening Field in particular though lacks the flexibility of Misty Illusions, but can still prove useful, especially in conjunction with other stat enhancing skills.