It is the exception to the rule. For one night of the year children are allowed to go against parental advice by dressing up and asking strangers for lollies.

As neighbourhoods around New Zealand prepare for the onslaught of ghouls and witches this evening, churches, theatre groups and the Auckland Museum will host Halloween functions to balance child safety with the youthful desires for lollies and fancy dress.

Auckland parent Shannon Alexander said having options did provide peace of mind.

"Obviously you go with them door knocking so it's not unsafe but I do worry about the message it sends.

"I spend forever telling my kids not to go up to strangers, but for one night it's okay. It seems wrong and confusing for a 4-year-old."

But Diane Westwick, who has three children, said she saw no problem with trick or treating.

"We did it and we're all fine now. You just need to make sure your kids are going in a group with adults.

"I always check the lollies when they come home and confiscate anything that looks tampered with or isn't wrapped properly.

"If they can't dress up and have fun on Halloween, when can they? People are way too precious these days."

Auckland Zoo will host its annual Boo at the Zoo Halloween event in which visitors can dress up and walk through the especially scary zoo grounds between 6 and 9 tonight. Tickets cost $25 and there will be prizes for the best dressed costumes.

This weekend, Auckland Museum will also open its doors after hours for a scary, and sweet, event.

Tickets cost $25 and guests are invited to dress up and navigate the museum's galleries with a torch.

Exhibits will include the grey lady, a mysterious ghost who haunts the corridors, an overly zealous dental nurse, a grumpy dinosaur, a woman with an oversized pet spider and a policeman trying to control the creepy crawlies.

Those with a sweet tooth will be enticed by a gory blood-red chocolate fountain and treat-or-treat goodies. The early part of the event is for children 7 and over, but it becomes R13 after 8 tonight.

Museum marketing manager Margi Mellsop said it was the first Halloween event the museum had hosted but staff had wanted to do something to celebrate the occasion for some time.

"A lot of museums overseas do something similar and a lot of the staff here are mums so it was quite nice to do something we knew would be safe and fun for kids."

For a cost-free alternative, Essex Park in Mt Eden will host an afternoon of mayhem today.

Seven witches and wizards will let kids participate in spooky entertainment created by some of Auckland's leading actors and theatre makers. Between 12.30 and 2pm guests will have their fortunes told, make puppets, get a zombie makeover and dance to ghoulish music.

Like many other community churches, St Peter's in Pakuranga will host a Light Party tomorrow as an alternative to Halloween.

Children will be encouraged to dress up as their favourite hero or heroine and will be entertained by balloon sculpturing, games, a sausage sizzle and Cherry the clown.

Light Party events originated in 2004 when founder Wendy Reid became concerned about the risks in traditional Halloween activities.

The vicar of St Peter's, Lucy Nguyen, said a Light Party was a positive way for children to learn about, and celebrate, death without fear or scariness.

"It's an opportunity for children and families to gather and learn about the origins of the eve of All Saints Day [October 31] before celebrating All Souls Day where we honour all people who have gone before us and celebrate their lives," she said. "It's about framing death as not being about darkness, it's not about being scared. Even though people have passed on we want to remember them fondly.

"It struck me that Halloween is an imported holiday that has not grown out of a culture of being light and fun for kids to do. It's dark and scary."

The people who started Light Party events wanted a positive alternative - "plus you still get to dress up and eat candy".

The Light Party will run from 2 to 4pm and entry costs a gold coin.