From FAQ on publisher's website:
Jumpers is a survival roleplaying game set in the infinite multiverse. So, what do we mean by this? Well, let's break it down piece by piece. If you aren't familiar with a roleplaying game, it is a game, played by two or more players, in which one player takes the role of a Jump Master, or the referee, and the other players take the roles of Player Characters. In a roleplaying game, the Jump Master devises a fictional scenario, complete with setting, characters, plot twists and scripted interactions, and has the players interact with this scenario using their Player Characters. While in most games, a Player Character can be an elf or a dwarf, a wizard or a barbarian, a cyborg or a hacker or a alien superhero, in Jumpers, the Player Character is simply a game representation of the player.
When we say 'survival roleplaying', we mean a game that requires players to think about the common aspects of life and living that many other RPGs disregard - things like food, sleeping, proper hydration. Additionally, Jumpers is rife with situations in which the Player Characters must find ways to survive in harsh conditions, with only the resources they carry with them. In many ways, it is a roleplaying game version of a television show like 'Man vs. Wild', or 'Survivorman'.
The game is set in the infinite multiverse. This term refers to the concept that the universe is actually made up of an infinite number of universes, each one slightly different from the next. Jumpers move between the universes from one scenario to the other. Many of these universes are very similar, and it would be hard for the players to tell the difference. However, other universes are drastically different - worlds ravaged by nuclear annihilation, or blessed with world peace... or populated by beings that are not necessarily human. Any scenario, any time line, any history... everything is possible in the infinite multiverse of the Jumpers RPG.