UPDATE: You can check out the rules for island creation on Google Drive, and comment on any specific part you want.
To help get your creative juices going, as well as to make it easier when trying to create an island on the fly, here is the current draft for island creation guidelines from A Sundered World. Let me know if you think it is missing something or needs clarification.
Given that A Sundered World is the somewhat stabilized result of numerous collapsed planar realities and accompanying rules, the word island has changed to become a kind of catch-all term that includes—for starters—chunks of rock, metal, ice, or bone, a cluster of root-entangled trees or ships that have been tied together, a massive creature, the corpse of a massive creature or entity like a
god, primordial, the burnt out husk of an aberrant star, or a
combination of the above.
Similar to steadings, islands have tags that describe what they are, how big they are, what lives there, and what they have to offer (though these tags can also be applied to specific steadings). An island's tags can help inform you about the steadings, monsters, and dungeons that can be found on it.
WHAT IS IT MADE OF?
The first step is to figure out what an island is made of. Islands can be made of virtually anything you want, though most are made of some kind of stone. Knowing what an island is made of can help determine how big it is, as well as what lives there or what resources it has to offer. Feel free to use multiple tags if, for example, an island is a bunch of ships lashed to a massive beast that swims through the astral sea, or miles of ice sheets surrounding the impaled corpse of an ice primordial.
- Astral Beast: The Astral Sea is full of strange creatures, some so massive that settlements can be built upon their backs. Is the creature alive or dead? Is it a whale, turtle, or something else? If people live on it can they control or communicate with it, or are they just along for the ride?
- Corpse Star: The island is the husk of a corpse star. Great if you are looking for cold iron, bad if you want to avoid eldritch horrors from beyond space and time, losing your sanity, star cults, being horribly mutated, and who knows what else. Corpse stars are thankfully usually located at the edges of known Astral space.
- Dead God: The whole god, or just part of one? Is the god's domain known? If you know which god it was, it can help inform what goes on around it: a god of life might spontaneously give rise to life, empower healing magic, or even bring the dead back to life, while a god of war might have tribes constantly fighting each other and have weapons "growing" out of it (Resource: Weapons?). Usually dead gods are inhabited by angels, religious folk, or celestial animals, and are located near the Golden Road or Fading Heavens.
- Essence: The dominions of gods were formed from the gathering of Astral essence, shaped by their wills. While it is difficult for lesser beings to even learn to temporarily craft simple weapons from it, it is possible for islands to be shaped out of it. Essence islands can be transformed at the whim of whoever made it, often appearing to be made out of something else.
- Ice: Is it an iceberg, a block of ice, sheets of ice, or some other shape? A block of ice could contain a creature imprisoned during the Dawn War, sheets of ice could be the result of an ever-bleeding primordial corpse, or it could have an ice vortex at its center. Ice elementals and other elemental creatures, and Winter Court fey can all be found.
- Metal: What kind of metal? Is it forged into something? This could include something like the City of Brass, the weapon or shield of a god, a massive ingot, or just an iron cube.
- Primordial: As with a dead god, is it the whole primordial, or just part of one? Most primordials are aligned to one or more elements, like a fire primordial, or a magma primordial (earth and fire). The cthon tend to settle on them, but elemental monsters are known to spawn from them.
- Ships: How many? What kind? Do they still work?
- Stone: Stone islands can be barren, but most can somehow support at least plant-life. Some formations near or from the Maelstrom are elementally charged (usually fire).
- Wood: A huge chunk of wood, maybe a branch, maybe an entire tree, several trees fused together, or even one of the dryarks that travel along ley lines connecting the Wandering Wyld's gate cities.
The Astral Sea is filled with plenty of small, useless chunks of stone and other debris, most of which are not worth mentioning. For the rest, here are some guidelines: small islands are usually not capable of supporting people on their own, and often lack any meaningful terrain features. Larger islands are more likely to have arable land, powerful spirits, or enough usable real estate to get a colony going. Keep in mind that these guidelines are for supporting a steading: if the steading is a trade city or fed through divine miracles, then it can exist on a smaller island.
- Small: The island has enough space to harbor a small group of people, but probably not enough resources to sustain them without the help of magic or a spirit. They likely hunt or gather elsewhere, salvage ruined ships, or engage in piracy to survive. Dungeons could include abandoned towers, sealed vaults, portals, or extra-dimensional spaces.
- Medium: The island can reasonably sustain a single steading, probably a village, town, or keep, but a city is also feasible, especially with assistance. There might be a mountain or two, small forest with a small animal population, lake, or other similarly-sized terrain feature.
- Large: The island can easily sustain an entire city, or two smaller steadings. There might be several mountains, an expansive forest with animals, a large lake with a stream, or a combination of a few.
- Huge: The island can easily sustain a couple cities, a city and another steading or two, or several smaller steadings. Mountains, forests, and streams are all possible.
Islands that have nothing of value are often uninhabited, except by things that want for nothing, have been bound there, or use it as a lair or waystation. For the rest you can represent what it does have to offer with some steading tags, like Safe, Resource, and Exotic, but there are some things to take into consideration with a few existing tags, as well as some new ones:
- Cold Iron: This is a type of Resource or an Exotic good that is especially effective against arcane magic and fey. Corpse stars are the only source of cold iron; not only does this make it difficult to procure, but its psychic residue needs to be scrubbed to prevent it from causing nightmares and insanity.
- Elemental Vortex: The island resonates one or more kinds of elemental energies, like fire, air, or lightning. The energy can be harnessed to power ritual magic, though exceptionally powerful weapons might need to be constructed on a vortex. A vortex can affect things that live there (leading to sorcerers and elemental animals), and also produce elementally-aligned crystals and metals.
- Food: Despite a lack of sunlight and water plants can still grow, even on stone islands (but not always). Spirits and angels can cause food to grow, even where it would normally not.
- Mobile: The island is not stationary. It could be a holy cathedral that drifts across the Golden Road, a giant beast swimming through the Astral Sea, located in a particularly turbulent region of the Astral Sea, an eladrin border city that fades from the Wandering Wyld to a ley line intersection (which might be more appropriate for a steading-level tag), or a kind of lost colony that drifted too close to a corpse star.
- Souls: An Exotic tag. Usually devils deal in soul trafficking (or rather, abduction), though Mes-Atbaru has its share and even some corrupt angels have been known to deal with them in the name of the "greater good". Souls have a variety of uses, from darker magical applications to fueling anima reactors.
- Transit: The island has access to an angel gate, teleportation circle, portal, or ley line, enabling quick, safe travel across the Astral Sea.
- Water: Water can spring from islands even when it "should not". Also, like food spirits and angels can produce water, as can a water vortex.
Not every island is inhabited (at least not in the typical sense), but when it is, use these tags:
- Mortals: This is a generic racial tag that applies to any mortal race, like dwarves, elves, halflings, tieflings, and the like. If there are one or more dominant races, you can add them as separate tags.
- Spirits: While minor spirits can be found in almost any natural feature, this tag is for islands that have a meaningful spiritual presence, whether beneficial or malevolent. Spirits can produce food or water (regardless of the island's size), and protect or enslave the island's inhabitants.
- Celestials: Angels, including corrupt angels and devas, are usually found on floating cathedrals, fading dominions, or god corpses. Such islands will often be found near the Golden Road and Fading Heavens, and steadings will often have the Divine tag.
- Elementals: Base elementals, but also includes elemental beings like djinn, cthon, and dragons. Often there will be an Elemental Vortex and it will be located near the Maelstrom.
- Fey: Elves, gnomes, hags, and other fey entities. The Wandering Wyld, border cities with gates linked to the Wandering Wyld, dryarks, and the like.
- Aberrants: Do things lurk on the island that should not exist, like aboleths, star cults, beholders, and other denizens of the Outer Gods? Then it probably deserves this tag. Corpse stars are obvious candidates, but islands with a secret cult dedicated to Dagon, or a forest filled with the Black Goat's dark young are equally valid.
- Devils: Asmodeus is the poster child of islands with this tag. Any island inhabited by devils or associated with them works. Typically these can be found in or near the Iron Circle.
If an island has something of value, whether food, raw materials, location, and the like, then there is probably someone (or something) that is interested in it, or interesting about it in some capacity. It is also possible that something just lives there and helps or hinders its inhabitants (or those that would like to inhabit it). Use the answers and tags generated in previous steps to describe at least one thing worth mentioning.
Examples: Dwarf thane, high priest, guardian angel (or angels), exceptionally powerful spirits, one or more fey lords, a dragon that regularly demands tribute, star cult leader, infamous monster, orc chieftain, djinn emir, rakshasa imprisoned in a secret vault, an ancient artifact, ruin, or spell, place of power, one of Autokrython's machines.