zeruslord wrote:I don't really like that plan. Gates being linked into the hearts of stars doesn't feel like a D&D problem, and you're begging for the Union issue where there's a bunch of world-wrecking badasses sitting around as glorified town guards. I think gates should be paired and not swappable, to maintain the limitations of the portal network on travel times.
Flavor-wise, anywhere unpleasant works. You don't have to link into stars; it could be the plane of fire, or of negative energy, or to a slaad nest in limbo, or the bottom of a desert of black sand, or
whatever. In any case, you get a situation where gates are heavily guarded, instead of in the middle of markets.
If gates are just two-way bridges, they're like passes through the mountains. Specifically, they're
exactly like passes through the mountains, and your DM is just describing the scenery a little differently. That's cool and all, but it's a lot of conceptual overhead vs. just putting some mountains on your worldmap, and no net benefit.
Now, I thought, perhaps wrongly, that the design goals for this thought experiment included (1) gates are something people can make, and (2) people still fly spelljammers about. For spelljammers to be worthwhile, there has to be a reason not to take gates. Specifically, there has to be a reason not to just ship goods through gates, and that reason must translate into a lower cost for shipping via spelljammer than via gate. since making spelljammer shipping cheap is fairly impractical, you have to make gates expensive. It's not as cool, and doesn't make for as good of a game if gate travel is inherently limited (because you can't march armies through them and have games about taking a beachhead, but also because the obvious solution is "build more gates"), so either you have to directly charge for using the gates (e.g. they run on souls) or add significant risk to using gates.
Stargate went with adding risk, and I thought that worked out pretty well. Heck, half their story mileage came from stories about new ways the gate could be used against them; why not select a proven concept?