Battlefield friendships are some of the most enduring, second only to the bonds shared by shipwrecked sailors and survivors of Willy Wonka's nightmarish factory tours. Solidify your acquaintanceships with today's Groupon: for $25, you get a rental starter package including a full day of play, rental equipment and air fills, and 200 paintballs at Fox 4 Paintball in Upton (a $50 value). Open play runs from 10 a.m. to 3:30 p.m. Saturday and Sunday.

Adrenaline and jocular exhilaration flood Fox 4 Paintball's sprawling, 34-acre field, a verdant wonderland carefully overseen by veteran staff. Show off an inner warrior as strong as Sylvester Stallone's man-corset when armed to the teeth with a semi-automatic paintball gun, mask, and ammo pouch laden with 200 rounds of colorful ordnance. A full day of play, fueled by unlimited compressed-air refills and trips to the snack shack limited by your pocket change, scatters jubilant warriors across Fox's wooded Valhalla and multitude of colorfully-spattered bunkers and obstacles. Warriors with fearsome appetites may replenish combative reserves with food and drinks brought from home after cathartic combat and strenuously competitive fetal-positioning.