Petter Nallo grew up in northern Sweden, and started playing both the American role-playing game (RPG) Dungeons & Dragons as well as Swedish RPGs Mutant, KULT, and Eon.
In 2000, as a freelancer, Nallo contributed to the second edition of Eon being produced by the game's publisher, Neogames.
In 2006, Nallo, Marco Behrmann, and Jonas Karlsson created a new dystopian Swedish RPG, Noir.
[3] In 2008, Nallo joined Jungle Peak Studios, where he and Edward Anton wrote scripts for the Swedish television series Azaya.
[4] About this time, Nallo, Anton Wahnström, Jonatan Gertler and Niklas Fröjd decided to create a 4th edition of Neo.