There’s something rotten on the streets of Bristol. The city’s IgFest begins today, offering a range of ‘urban games’, in which groups of players take part in themed chases around the Old City, following mission objectives and immersing themselves in living interactive narratives. In other words – they’re playing video games, but on the streets and in person. For real.

The highlight of this year’s event, which runs until 8 September, is likely to be 2.8 Hours Later, a zombie chase adventure that challenges participants to navigate and survive an undead apocalypse. Organised by Bristol-based developer Slingshot, the game involves following a map to a series of locations within the allotted 2.8 hour running time. En route, team members will be attacked by zombies – or more accurately, actors dressed as zombies, although it’s very easy to get caught up in the atmosphere.

There are two other headline games to get involves with, all running every evening of the festival. Cargo, co-designed by Slingshot and The Orchid Project has you legging it through the city attempting to deliver a package to a boat while being helped – or hindered – my a mysterious AI that contacts you via your phone. Incitement by Splash & Ripple is a stealth game in which players attempt to bring down a dystopian Authority. Apparently combining street gaming, theatre and digital technology, it’s set to close with something of a spectacular surprise finale – perhaps an actual revolution?

Urban games have been around for a number of years, often organised by interactive art collectives like Blast Theory or offbeat creative agencies like Hide&Seek. Theatre companies like Punchdrunk are also exploring the boundaries between interactive theatre and gaming.