(Lisa Bolton/The Washington Post) Will one of these pumpkins become your prize-winning Jack O'Lantern? (Lisa Bolton/The Washington Post)

Ordinarily, we don't encourage the combination of alcohol and sharp objects. But when bars host pumpkin carving contests around Halloween, we'll make an exception. All of these competitions are free to enter, and they all have one golden rule: The actual carving of the pumpkin must be done at the bar, not at home.

Jimmy's Old Town Tavern in Herndon hosts its pumpkin carving contest tonight. Owner Jimmy Cirrito says the bar has "an unlimited number" of pumpkins to hand out to guests, along with steak knives for carving. (You can bring your own carving knives or tools, and props to decorate the pumpkin are also encouraged. Show up whenever you want to start making the Jack O'Lantern; the only rule is that work must be finished by 11 p.m. Judging takes place at midnight with a $50 gift certificate for the winner, a $25 certificate for the runner up, and "a pumpkin ale" for third place, Cirrito says. All pumpkins will be used as decorations for Jimmy's Halloween party on Saturday night, which includes a "scary scream contest" at 10:30, and a costume contest with a $150 cash prize for the winner.

On Sunday, the Red Derby's annual pumpkin-carving contest will be held from 7 to 9 p.m., with the winner announced at 9:30. Ten pumpkins will be handed out at the bar, so bring a team or just BYO pumpkin. (Again, even if you bring a gourd from home, the bar stresses that all work must be done "on premises.") Kid-safe carving kits will be provided to minimize the loss of fingers. Winners receive gift certificates from the bar.

Helix Lounge's night-before-Halloween contest is the most popular around: Thirty pre-scooped pumpkins will be handed out at 6 p.m. Wednesday, but teams and individuals arrive right after work to secure a pumpkin and a set of safety tools. Prizes include a weekend night at the Helix Hotel for the best overall design and a $50 gift certificate to the lounge for the top “locally themed” pumpkin featuring a Washington landmark or politician. Pumpkin beers and pumpkin-spiced cocktails are served at happy hour prices until 9 p.m.