INSTANT [play]GROUND is a portable instant game that can fit in a suitcase and travel to different sites to activate forgotten, unused or misused parts of the city. The game takes no longer than an hour to install and users can start playing and after several games, IpG is placed back into the suitcase and can travel to another site. The area is instantly transformed into a play-zone. Within the context of the Urban Prototyping event in San Francisco in October 2012, a series of sites were identified (corridor areas, alleys and residual spaces between buildings); the traveling project was tested as an instant activator to engage the players and the public audience. The project has a great potential to be used by a wide range of user groups, be mass-produced therefore globally replicated, and to be a portable urban catalyst to instigate and support civic engagement and participation.