From Nature: Zombies are on the attack. Victims’ organs must be replenished to save humanity from the undead. But only players with an understanding of cells, tissues and organs can regenerate the lost body parts. This is the challenge set forth in Progenitor X, a problem-solving video game in which players learn how to reprogram more than 200 human cell types. “People play Progenitor X because it is fun to learn some things about science as they play,” says game developer Kurt Squire. Squire is one of a growing number of informal-science-education (ISE) researchers, who focus on providing learning experiences outside of the formal classroom environment. The field encompasses a diverse group of talents, including video-game developers, as well as people who design, develop and evaluate science-education experiences for museums, television shows, after-school programmes, science festivals and national parks.