Day Z is a set of campaign wargame and RPG skirmish rules for games set in a zombie apocalypse. The author writes:
This DayZ ruleset is played on a simple grid map, with each grid square representing an area fifty meters on each side. The majority of towns and rural areas can be represented by a twelve-by-twelve map, though some larger areas such as Chernogorsk, Elektrozavodsk, and Solnichniy are better-suited by a double-wide, twelve-by-twenty-four map. The game starts out on the coast of Chernarus, a former Soviet republic currently experiencing a virulent outbreak of a plague rumored to originate from an island offshore of Taviana. The plague does not appear curable, and causes symptoms in its victims similar to ‘zombies’ described in popular media. Its extents are currently unknown, but it is believed to have spread across much of Europe and the Middle East.