In TranscendenceRL, the “Rogue Frontier” (the counterpart of the Black Market) is a force of chaos in gameplay. It is planned to reveal itself through small, unexpected events. One idea that I came up with just now is to have something happen when the player docks at a station where a certain ship is also docked.

In the case of Transcendence, when the player docks at a Commonwealth Metropolis where an outlaw freighter is also docked, the player should get a hint about smuggling for the Black Market. Such an event might not happen reliably enough given purely random conditions, but in that case, I think it would make for a good Easter egg.