I’m not a big RPG guy, but that news about adding “mystical gateways” to the Forgotten Realms canon is interesting. Yes, it will unbalance campaigns that get crazy with them, but for some campaigns it may be the balance they want. But that’s not what I’m thinking about.
Suppose you had a campaign with a couple of towns, and a trade route between them. Then some wizard discovers how to open a portal between the two towns. There is great public interest, and the wizard gets the bright idea of restricting use of his/her portal to those willing to pay him/her a fee. (Maybe the portal saps more of his/her energy depending on how much mass you move through it. I leave the wizard’s motivations up to you. Maybe the portal is preexisting but the wizard discovers how to make it more stable.)
So, wealthier merchants are able to get their goods to the other town much more quickly, giving them an economic advantage, and poorer merchants lose out on this advantage, thereby becoming even poorer. The king sees how this is wreaking havoc in the mood of the citizenry and hires the players to put a stop to it. (Or, perhaps, to stop the band of former forest bandits who, upon the drying-up of their old trade-route pickings, have decided to exercise their forest ambush tactics in town!)
This illustrates a couple of good game-design maxims: 1) Turn difficulties into the path. 2) Steal economies from real life. The latter maxim drove the first stage of development of my card game in progress, Napalicious. But I’ve said too much already…