It's a play rewriting the rules of theatre - a live performance with a supporting cast of the undead.

Starting in Auckland tomorrow night, Apocalypse Z offers an "immersive theatre experience" to its hundred-strong audience. They'll be admitted to a purpose-built military outpost in Aotea Square and there, with just four guards protecting them from the zombie hordes outside, they will face challenges that alter the way the show plays out.

Who will fight? Who will flee? Who will risk their life to save another?

We got writers-actors Simon London and David Van Horn and director Andrew Foster to explain the rules.

Other than an outbreak of zombies on TV, movies and phone apps, what has caused the zombies in this scenario?

It's a virus called Z, which is brought into New Zealand on an overseas flight. It begins when you are bitten by an infected person. Within two hours, the infected are fighting a battle in their hearts and minds between being human and succumbing to bloodlust and hunger. Two days later, they'll be in the active decay stage and within five days the latter stages of advanced decay. Death usually occurs on day six but, by that time, chances are they've infected many, many others.

You can find out more about how survivors are coping and preparing by visiting their website.

Can these zombies run?

It all depends where they're at in the cycle of infection. In the first two to three days, yes, but after they can struggle to get around because hard tissue and bone is deteriorating.

Can these zombies talk and, if so, do they say anything but "braaaaaaaaains?"

As the virus progresses, they lose the battle to retain human faculties like speech and end up moaning and groaning. It's a very painful process.

So are the zombies more Evil Dead or The Walking Dead variety?

They're an amalgam of both plus a little of the 28 Days [Danny Boyle's 2002 UK horror film] variety. It's a virus, rather than demonic possession, which causes the condition and the action. It's concerned with what happens when society is on the brink of total collapse.

How much protection can those soldiers provide?

They'll do their best to keep everyone safe but they're just four people against an unknown number of zombies, so the odds are stacked against them. It means everyone has to listen carefully to the instructions they're given and make choices, based on their own moral code, about how best to carry these out.

What sort of tasks might the audience have to undertake?

Stemming the flow of blood if - when - anyone gets attacked, getting the power back up and running when it goes down, guiding a transporter to the outpost and deciding how to deal with any survivors who are bitten.

What does happen if a zombie attacks anyone at the outpost?

Tough question. If someone gets bitten, they're most likely infected so it's up to the survivors how to proceed. They might be dealt with on humanitarian grounds - quarantined to live out their last few days in isolation - but the world's disintegrating so who knows what rules may apply? We've got some fairly stringent checks and tests in place to ensure no zombies sneak into the cast.

What should audience members wear and are their own weapons permitted?

Come dressed in survival gear that is appropriate to the conditions on the night, but be prepared to get wet from water and blood. Given the recent run of good weather, there's likely to be more of the latter. Weapons will be confiscated. We simply can't run the risk of having nervous, trigger-happy survivors at the outpost especially as the tension builds and nerves start to fray.

Should you recognise one of the zombies - say from a small role on Shortland Street - should you show them mercy because of it?

Exercise some humanity because in this scenario so-called celebrities aren't immune from the Z virus, which strikes irrespective of fame, fortune or whatever. Chances are they've been infected on the way to the outpost.

You're opening tomorrow night on Queen St. Isn't there a risk this could all go horribly wrong - or is going horribly wrong actually a good outcome?

Well, anything can happen in a situation like this but safety is our top priority. We've actually consulted psychologists about how people might react and what contingency plans to put in place for the unexpected. Our best advice is don't come if you have a phobia of blood.

What: Apocalypse Z, interactive play
When: From April 12 to April 27 at Aotea Square. Tickets from the-edge.co.nz
Info: whatwillyoudotosurvive.com

- TimeOut

By Dionne Christian