In Strategic Primer, my strategy game, players can lift the technological level of their forces quite rapidly from the package of “advances” each player starts with. I’ve described before how in the first campaign players went from chariots to space in only a few turns, but even at the more usual, somewhat slower pace imaginative or well-read players will eventually reach the point where they can send explorers to other worlds.
This might be by launching an interstellar spacecraft or probe, or it might be by implementing any of the various devices that science fiction and fantasy authors have described to transport people between parallel worlds. (Players’ possibilities for discovery are not even limited by strict consistency with our current understanding of how the universe works.) Managing any of these, with a possibly exponential increase in complexity, could create some problems for me as game designer and campaign Judge.
Because of this, and to promote player interaction after these technologies are invented in-game, I added one simple concept to the rules: There are an indefinite number of worlds in the game, but they are the same worlds no matter how you travel from one world to another. (To help this abstraction, in the game each star has only one habitable or otherwise “interesting” planet or other major world.) So a player who discovers paratemporal transposition and one who invents a starship are likely to end up on the same world.