Virtual graphs, virtual networks, connectivity expressed by derived relationships rather than represented directly… I last wrestled with these concepts in Corrupt Beneficence. In this post I’m waving an 18xx/route-building stick at them. The following discusses a possible mechanical representation of the operational side of 18xx as a card game.
Imagine cards. There are cards which simply represent railroad track and cards which represent revenue locations (cities and towns). Some revenue locations are also the home stations of various companies. Thus, for instance, the NYC card might also be the home station of the NYNH&H.
The director of a company, say the B&O, would have a card before them for Baltimore. On the Baltimore card they’d place a token for the B&O’s (home) station. Other revenue locations (non-home stations) would have spaces for companies to place stations ala the normal model. If player were running a different company than the B&O, they would have a different card of a different revenue location for that company’s home station if enough cards for that revenue location exist in the game
During the course of the game the B&O president would place track cards adjacent to the revenue location. Cards could be placed on each of the four sides (perhaps limited by game phase), forming a stack or route leading away from that location. The president might also place revenue locations at the ends of such stacks, assuming that the stack contains enough cards to satisfy that revenue location (eg the Lancaster card might require 3 track cards before it can be connected/placed).
And this is where the network enters. There are multiple copies of the revenue location cards. Thus for instance, the B&O may place track from Baltimore to Lancaster and thence to Chicago. Meanwhile another, say the C&O places track to NYC, and then Chicago and thence Scranton. There would be two Chicago cards, one on the B&O’s network, and one on the C&O’s network. Indeed a company might have the same revenue location on several of the routes that fan out from the edges of its home station.
This is where the network enters. All those repeated Chicago cards are the same location. Thus in the above example the B&O might run a train from Baltimore -> Lancaster -> Chicago (transitioning to the C&O’s network) -> NYC -> Scranton. In fact a route might transition across several different company networks as they connect shared cities into their routes. And in the above example the B&O might drop a token in Chicago (and thus on all the Chicago cards), thus allowing them to run trains out of every route in every company’s stack that contains Chicago. As companies acquire tokens in other company’s networks, they might also place track and revenue locations directly on those networks (where visible from their tokens) instead of onto the networks directly attached to their home stations. A virtual implied network, all build from cards!