Note: Apologies for how long this took to put together; hopefully you'll find it worth the wait.
The Infinite Mirage is a dream come true. Like a dream, anything one can think of might be found here, and like a dream, most of it will vanish as soon as one leaves. Still, this simple fact has drawn many people here, and the would-be utopias they've formed are things of beauty in any plane. But the riches there hide the desperate struggle they go through to obtain their desires, and the prison this plane becomes for many.
The outer circle is temperate and idyllic, with rolling fields of tall grass, groves of sweet fruit, tall mountains surrounding valleys, and so on. This is a bit deceptive, however, as it is something of the product of long-term magic use by the inhabitants. Here and there, traces of the original landscape can be found - white, fine sand under an iridescent sky. Inbetween the leftovers and the newfound paradises, transitory landscapes can be found, with trees or grass forming out of the sand and progressing until they resemble the rest of the outer circle.
The communities found in the outer circle have had difficulty in the fact that though the land is beautiful, food grown here does not sustain them. The difficulty is that they can trade little of their personal wealth elsewhere, as most of it merely dissolves to sand in other planes. Instead, travelers go deeper into the plane to gather up powerful conjuration components which can then be transmuted into more "real" sustenance, or others seek deals with other planes for supplies. Some have been become trans-planar tourist spots, offering wonders few other planes could duplicate.
More rarely seen are the Obscura, wellsprings of illusion. Winding their way from the inner circles to the outer circles like rivers, few dare to enter - much less cross - these zones. Various creatures of shadow dwell in these dark patches, where shades begin to dim as pitch-black, ink-like shadows color everything in high contrast, while colors dim and gray. They also contain one of the most valuable assets on the plane - matter that can be shaped into something real. It is not unknown for some to venture into these areas to collect the shadowy material, which is then sold at the various communities about the plane. Even food and drink can be crafted with the shadowstuff and magic, though most imbibe such creations in moderation. Those who consume too much of it find themselves becoming changed by it, gaining strange powers but also weakening in various fashions, from madness to infirmity.
- Impeded Magic: All spells that are not illusion or universal spells. The Spellcraft check is only made at (DC 10 + the level of the spell).
- Enhanced Magic: All illusion spells are heightened by one level (as if Heighten Spell had been used on them, but the spells don't require higher-level slots). Spells and spell-like abilities that are already heightened are unaffected by this benefit. Alternately, instead of gaining this benefit, a spellcaster may decide to add a single metamagic feat to an illusion spell, but only if the metamagic feat normally requires that the spell's level is increased by one (such as for extend spell, silent spell, or still spell).
- Magically Morphic: Illusion spells that alter the appearance of the local terrain may modify it semi-permanently (hundreds of years) if cast repeatedly in such a fashion. This requires a caster level of 20 to do at once. It can be altered more slowly by casting the spell in the same fashion at least once a day, and the required caster level "accumulates" until it reaches 20. So, for example, a 2nd-level caster casting an illusion spell once a day would take 10 castings and 10 days to make it semi-permanent. Similarly, if a 2nd, 3rd, and 5th level caster all cast the same illusion spell once a day in the same fashion, it would take them 2 castings each and 2 days.
The first inner circle is both more malleable and less permanent, making it more hostile. Supplies must be carried, for few inanimate objects remain unattended in this area, sand burying them in hours or days. A rolling desert of dunes, this realm is made up of the malleable sand only found occasionally on the outer circle. Despite the bleak appearance of the land, there is no extreme heat, and the light is merely that of twilight, shifting stars spinning through the sky. It darkens to pitch-black as one approaches to the dark black sand of the Obscura. Here, the laws of reality begin to bend more profoundly, with even gravity itself lessening.
Only dedicated and powerful illusionists can afford to call this place home, and it largely appears unpopulated. Instead, one usually encounters beings, monsters, and places similar to those from one's past. These sorts of mirages are often oddly familiar, but details are always off from the original memory. Sometimes when folk travel close together, meldings of their memories are warped into entirely new, and sometimes intensely bizarre mirages. Other times, one will encounter things created by the past experiences of other travelers, lingering past their presence. Though these fade away over time, they do not fade in the presence of their 'creator'. Though they fade to sand when brought outside the plane, they are real enough in this land, and affect things normally while they do exist. It is not unknown for those from the outer circle to seek out these mirages, for they can often be brought back... though they do not venture into the outer circle of their own accord.
In the Obscura, the mirages tend to have a more nightmarish quality, and tend to appear more often as enemies or predators of their creators. Ironically, there are fewer physical shadow creatures, as there is less reality to support any such ecology. Instead, mirages and less substantial creatures make up most encounters in this realm. Though overall less dangerous, it has the potential to be far more dangerous on rare or unique occasions.
- Low Gravity
- Impeded Magic: All spells that are not illusion or universal spells. The Spellcraft check is only made at (DC 15 + the level of the spell), however.
- Enhanced Magic: All illusion spells are heightened by two levels (as if Heighten Spell had been used on them, but the spells don't require higher-level slots). Spells and spell-like abilities that are already heightened are unaffected by this benefit. Alternately, instead of gaining this benefit, a spellcaster may decide to add a single metamagic feat to an illusion spell, but only if the metamagic feat normally requires that the spell's level is increased by one or two (such as for extend spell or empower spell).
- Magically Morphic: Illusion spells that alter the appearance of the local terrain may modify it temporarily if cast repeatedly in such a fashion, lasting several days. This requires a caster level of 10 to do at once. It can be altered more slowly by casting the spell in the same fashion at least once a day, and the required caster level "accumulates" until it reaches 10. So, for example, a 2nd-level caster casting an illusion spell once a day would take 5 castings and 5 days to make it semi-permanent. Similarly, if a 2nd, 3rd, and 5th level caster all cast the same illusion spell once a day in the same fashion, it would take them 1 casting each and 1 day.
The second inner circle is more a sea of iridescent mist than a landscape, as the sand begins to drift towards the sky until it becomes a fine mist of dust and sand, swirling and obscuring vision. Though it is not immeditately dangerous to breath, those who sustain themselves on the air of this plane risk losing their reality and becoming little more than just illusions themselves. Those who have perished in this fashion become insubstantial illusions, aping out scenes from their past for all of eternity. Even objects become instinct, fuzzy versions of themselves if left about entirely. Here gravity becomes lost entirely, and one can will oneself in any direction. There are few hazards to be found here other than the plane's essential nature, save within the Obscura.
In the veins of Obscura that wind through the plane, these faded illusions become real, and often dangerous, replaying more violent or traumatic experiences in their lives. Even objects can be dangerous, as sometimes they are left drifting at dangerous speeds... or may be dangerous by their mere proximity. They fade to nonexistence again outside the Obscura, but are dangerous while they remain there.
- Subjective Directional Gravity
- Impeded Magic: All spells that are not illusion or universal spells. The Spellcraft check is made at (DC 20 + the level of the spell).
- Enhanced Magic: All illusion spells are heightened by three levels (as if Heighten Spell had been used on them, but the spells don't require higher-level slots). Spells and spell-like abilities that are already heightened are unaffected by this benefit. Alternately, instead of gaining this benefit, a spellcaster may decide to add a single metamagic feat to an illusion spell, but only if the metamagic feat normally requires that the spell's level is increased by one to three (such as for extend spell, empower spell, or maximize spell).
- Magically Morphic: Illusion spells that mimic a real thing actually reproduce an actual copy of that thing here for the duration of this casting, though such a replication vanishes outside the bounds of the second or third inner circle of the Infinite Mirage. These copies can inflict real damage, though the caster cannot create anything with a challenge rating or character level (whichever is higher) greater than half his caster level in this fashion. This includes traps, hazards, and any other type of challenging or dangerous encounter.
- Thick Mists: The mist blocks all vision (low-light vision, darkvision, etc.), scent, and hearing beyond 30 ft. In addition, all detect spells have their range similarly reduced to 30 ft.
- Fading: This is a special trait unique to the Infinite Mirage. Creatures who are not outsiders native to this plane begin to fade entirely. Every 24 hours a character spends here, they must make a Will saving throw (DC 10 + 1 per hour spent here) or take 1d6 points of temporary ability damage to their lowest ability score (determine randomly if there is a tie). If an ability score is reduced to 0 in this fashion, they become illusions that wander this plane, their body fading away entirely. Additionally, characters that die in this plane also fall victim to this fate if they or their body has remained on this plane for an hour or more. The same is true for inanimate objects that have been in the plane for an hour or more if they remain away from a character for more than a turn, though magical items get a saving throw just as a character does. If they succeed, they must then continue to make saving throws each hour (as a character would) until they fail or are taken up by a character again. Only a true ressurection or a wish or a miracle followed by a ressurection spell can restore a character that dies in this fashion, though objects are lost forever.
Though much like the second inner circle, the purity of the illusion magic here increases greatly, breaking down people and objects so fast it can be seen clearly. In addition, those who fade here, though still a form of illusion magic, remain real but nonsentient, mockeries of their former selves. This makes this area even more dangerous, and they change the local landscape to fit their former existence. For example, an mock-elf from a woodland home will replicate that woodland environment in their immediate vicinity, though this can be far more dangerous when it comes to mock-outsiders, who even bring copies of their former planes with them. Sometimes such copies even bring their companions or inhabitants of the realms they recreate, though that can make it very hard to determine which is the "core" copy. The random quality of such dangers can make this area of the plane extremely hazardous beyond the magical erosion that occurs here.
In the Obscura, all of the above holds, though as with the second circle, the illusions that wander this circle become more dangerous and violent. Furthermore, those closest to the purest example of shadow magic risk becoming altered by it by their mere presence, becoming tainted by it as mentioned above.
Finally, in the core of the plane, even the mockeries and illusion that infest this plane are devoured by the spinning, swirling mass. A globe of marbled iridesence and shadow, it is said to slowly consume the reality of the plane in order to keep this plane from ever becoming truly static. Here, one risks becoming consumed entirely in mere seconds.
- Subjective Directional Gravity. Near the core (within 100 ft.), the core exerts a normal gravity on all nearby.
- Limited Magic: All spells that are not illusion or universal spells do not function.
- Enhanced Magic: All illusion spells are heightened by four levels (as if Heighten Spell had been used on them, but the spells don't require higher-level slots). Spells and spell-like abilities that are already heightened are unaffected by this benefit. Alternately, instead of gaining this benefit, a spellcaster may decide to add a single metamagic feat to an illusion spell, but only if the metamagic feat normally requires that the spell's level is increased by one to four (such as for empower spell, maximize spell, or quicken spell).
- Magically Morphic: Illusion spells that mimic a real thing actually reproduce an actual copy of that thing here for the duration of this casting, though such a replication vanishes outside the bounds of the second or third inner circle of the Infinite Mirage, or beyond the third inner circle of the Infinite Mirage if the challenge rating or character level (whichever is higher) is greater than half his caster level. These copies can inflict real damage, though the caster cannot create anything with a challenge rating or character level (whichever is higher) greater than his caster level in this fashion. This includes traps, hazards, and any other type of challenging or dangerous encounter.
- Thick Mists: The mist blocks all vision (low-light vision, darkvision, etc.), scent, and hearing beyond 15 ft. In addition, all detect spells have their range similarly reduced to 15 ft. Most of the recreated environments ignore this restriction, though only within their bounds.
- Fading: This is a special trait unique to the Infinite Mirage. Creatures who are not outsiders native to this plane begin to fade entirely. Every 24 hours a character spends here, they must make a Will saving throw (DC 10 + 1 per minute spent here) or take 1d6 points of temporary ability damage to their lowest ability score (determine randomly if there is a tie). If an ability score is reduced to 0 in this fashion, they become illusions that wander this plane, their body fading away entirely. Additionally, characters that die in this plane also fall victim to this fate if they or their body has remained on this plane for a minute or longer. The same is true for inanimate objects that have been in the plane for a minute or more if they remain away from a character for more than a turn, though magical items get a saving throw just as a character does. If they succeed, they must then continue to make saving throws each minute (as a character would) until they fail or are taken up by a character again. Only a true ressurection or a wish or a miracle followed by a ressurection spell can restore a character that dies in this fashion, though objects are lost forever. In the Obscura, the character just make two rolls, the first to determine if they become shadow-tainted, and the second to see if they fade as well. In the core of the plane, the same is true, only it occurs every round rather than every minute. Only a wish or a miracle followed by a true ressurection spell can restore a character that dies in this fashion near the core, though objects are lost forever.
(Though no firm rules are presented for the shadow-tainted, a spot solution is to use the shadow template from Manual of the Planes, found on page 190, but the victim loses 1d6+2 points from their lowest ability score as well, permanently.)
