D&D General Campaign setting in a Gas Giant World with Floating Islands

[pnewman]

Here is an image of Neptune. Its blue color might be what a gas giant might look like with an earthlike atmosphere.

Hi, It would probably be grey because clods of water vapor are grey, and if the planet is not warm enough for clouds of water than it doesn't have an earth like atmosphere. To us it would probably look like a ball of thick smog. Blue would be prettier though.

 

[Yaarel]

Hi, It would probably be grey because clods of water vapor are grey, and if the planet is not warm enough for clouds of water than it doesn't have an earth like atmosphere. To us it would probably look like a ball of thick smog. Blue would be prettier though.

In our planet Earth, the atmosphere makes the sky look blue, because of the way it obsorbs and refracts (scatters) sunlight.

Notice the bluish color of the atmosphere around Earths edge.

 

[Kobold Avenger]

Carl Sagan once theorized about what life might look like if it existed "on" ("in"?) Jupiter. I think it involved enormous creatures that "swam" in the gas clouds.

The first question to ask is how these islands "float". If the answer is that the gas is so dense that they float normally, then you've just got a normal island/water world but with something other than water. Which isn't terribly interesting.

So assuming that it's actual gas, and that you have some mechanism by which the islands float, I see two potentially interesting differences between this and a more typical island world:

I think there would be a mineral in all floating islands that naturally floats, Airships might also use this mineral to remain airborne. But it isn't a fuel to burn, and airship without fuel or propulsion just stays floating in place.

1. 3D. Not only do the ships travel in 3 dimensions, but the islands themselves won't necessarily all be at the same altitude. What determines the altitude of a given island, and does that altitude have any implications for status/trade/etc.? Are some strata better for travel/trade, but others have more pleasant climate? Maybe the calm ones are good for airships, but the stormy ones are good for growing crops? Are there strata perpetually enshrouded in thick clouds, where "bad guys" like to hide?

I think that usually the islands higher in altitude might be the ones of higher status and possibly better for agriculture, but the lower altitude islands might be better for industry.

2. Movement. Do the floating islands change position relative to each other? What are the implications for political structure and alliances?

I think some islands would be of stable positions, but others might shift positions a bit.

 

[pnewman]

In our planet Earth, the atmosphere makes the sky look blue, because of the way it obsorbs and refracts (scatters) sunlight.

Right, but a gas giant has such a thick atmosphere that (if it is at earth like temperatures) than it's going to look overwhelmingly grey when you look down on it or while on it you look down or sideways. It might well look blue as you look up though.

 

[Laurefindel]

I would treat falling as an analogue to be lost at sea; At one point you'll just float in the "lower atmosphere" where you can either be rescued or eaten by cloud-sharks or whatever. Perhaps earth-islands can have their equivalent of "shallow waters", so when your 4-year old kid falls off the pier, it isn't too hard to retrieve them.

 

[Shiroiken]

If you're interested in setting up an interesting metaphysics for it, I'd suggest looking into the first book of the Deathgate Cycle. It has a world of air, with island floating at different levels that move around at a fixed speed (keeping the distances fairly stable). If you don't care about that kind of stuff, you can just have it be "because that's they way it is."

Falling in such a world would be a serous concern for anyone who leaves the islands. Since you're obviously going to have a high level of magic in such a world, it's likely they would have created some magic item to help with this. My suggestion would be the equivalent of a life-preserver, which like the Ring of Featherfall would trigger after falling a certain distance. Once triggered, the character would begin to float like the airships, but lack any method of propulsion. This might be cheap enough for every sky sailor to have one, or costly enough that only captains and important people have them. For the type of item, I'd suggest a ring, since it's not likely to be lost before or during the fall.

The size of the world probably isn't relevant. In most campaign settings you only have a "known area" that's the focus of the game. I'd simply setup the area you need for your game, and like the age of sail there's going to be quite a bit of travel time between locations. Given the setup of the setting, I suspect that this travel is going to be the primary focus of the game anyway. You might consider adding/modifying spells to allow for increased speed, allowing nobles and other important people to hire casters for this service.

As for creatures... there's a lot of science fiction you could use for ideas. The idea I recall was for floating, gas filled, jellyfish type creatures. Flying creatures would have to stay fairly near islands, since they have to eventually land.

 

[jgsugden]

Consider eliminating the 'world' and placing the campaign in the Astral Sea, with ships navigating between large structures that float in the sea ('asteroids', constructed cities, dead Astral Juggernauts, dead Gods, etc...) This is essentially what I have in my Astral Sea.

The ships can allow movement that is much faster than most beings can accomplish with just their minds, so the ships are essential for the long voyages. However, if someone 'falls off', they will not fall forever as they all float in the Astral Sea.

I introduced this back in the early 90s as a way to incorporate Spelljammer - and it was a hit with that group of players. They essentially abandoned their homeworld to sail the Astral Sea and go on adventures there. It saw heavy use from 1991 to 1994, then has been an occasional place visited since then.

 

[Kobold Avenger]

I would treat falling as an analogue to be lost at sea; At one point you'll just float in the "lower atmosphere" where you can either be rescued or eaten by cloud-sharks or whatever. Perhaps earth-islands can have their equivalent of "shallow waters", so when your 4-year old kid falls off the pier, it isn't too hard to retrieve them.

Earlier editions had the Solid Fog spell, I think something like that would exist "naturally" in the world in patches.

 

[Dausuul]

So here's some things I'm pondering, what happens if someone falls off an island or a ship? Should there be a bunch of additional last chances, before falling into unknown oblivion of whatever might be at the planet's mysterious core or lower atmosphere?

Everyone else is exploring world-building questions, so I'll dive into this more mundane one: Given that forced movement is relatively common and easy in 5E, how do you run a D&D game in a setting where many if not most combats take place on the edge of a bottomless pit?

One solution is to house-rule "escape hatch mechanics" where you get a last-ditch saving throw, or something, to avert a fatal fall. However, I don't really like that--for one thing, it leaves too much up to the whim of the dice. I would instead look at solutions within the game world.

First would be to have equipment that gives you a second chance, which could be as simple as nets that hang below an airship (at least a well-designed, OSHA-compliant airship) to catch those who fall. Second would be a feature of the world where falling into the depths doesn't result in automatic death. Perhaps there is a layer where those who fall end up drifting in some kind of coma or temporal stasis, and it is possible--albeit dangerous!--to descend to that layer and rescue them, like rescuing someone from the Underworld.

Hmm. Guess I ended up at world-building after all...

 

[aco175]

I like @Oofta idea about a tree/bramble layer surrounding the core of the world. Things fall and get stuck to layer where undead and plant monsters do bad things to them. Islands can float because of some gas the collects in the plant material and breaks free allowing it to float and grow to float higher. This means that the islands can be shot down as well and fall back to this plant layer. I can see a few adventures where the island springs a leak or fallen PCs need to be rescued from the bottom layer.

Since the islands fall, there can be all sorts of ruins on the base layer that hide monsters and treasure. Ferrymen brave the danger for gold and can try to pick you up when they see your flare, but the lurkers also see the flare. There could be secret tunnels through the layer that allow slipping through the center of the world to pop up on the other side. Of course, there is risk with this as well.

Throw in a BBEG necromance that can float up large groups of undead to attack low-hanging islands and you have problems. A skyport that repairs ships that were salvaged from the deep who happens to have a pilot that is crazy enough to ferry you to the Ruins of Chaka for a cut of the action, as long as the 1,000 Island Imperium does not catch wind of it.