You read that right, when crossing any door you can make it a gateway into a different realm where fantasy is real. However, there's some rules like humans cannot exist there (You can bring them later), things from this world cannot go to Earth (You can bring things from Earth there), time flows faster than on Earth (You decide how much, but is to be at least a day), the technological levels cannot go beyond ''Medieval Times'' and if magic exists, it cannot alter the past or revive the dead other than as undead.
The many details of this world are up to you, like making it either round or flat, as well shape the cosmos around it. As for the people and creatures, they won't be mindless slaves that obey your commands, they're beings of free-will and their view on you shall be determinated by your actions. Some details before starting to imagine, you'll be cured of any physical ailment upon going to this world for the first time and when you die on Earth, you'll revive on the other world, but becoming permanent resident there until you die again.
For example, this would be my world...
My world is a round planet (A little bigger than Earth), with the days lasting 24 hours as the world rotates around the Sun, most of the twelve months lasting at least 25 days and beyond the planet, there's one moon and is part of a solar system that includes five more planets (As well meteors and comets). Besides animals from Earth, rare beasts with mystical properties exist and then there's Spirits, which can take many forms and bring either good or bad. In this world, all living beings come and return to Aturan The Spirit of Life, receiving the ''Final Sleep'' upon death and eventually coming back through reincarnation. Meanwhile, the sapient beings shall be granted their own ''Dream World'', which can either be a paradise or nightmare depending on their what life they lived, but you can still ask to be reborn or wait for a long time until your spirit is cleansed, becoming ready for reincarnation. All the sapient races have one universal trait, as all women being able remain infertile as long as they want until wishing to have children, preventing any undesired pregnancy and the risk of overpopulation. Most of them live in Gard, a massive continent similar to Eurasia and what lies beyond of the ''Western Ocean'' is a mystery for them (Fearing the unknown waters and sea monsters that may live there), thus keeping to themselves on their own communities akin to Classical Antiquity (Babylon, Egypt, Greece and Rome).
As for who lives here, the main races are...
Satyrs: Humanoids with goat ears, tail, legs, and horns. Also known as ''Children of the Forest'', they are elusive and agile thanks to their animal traits, living in tight-knit communities and practicing vegetarianism. Although being peaceful and trying to not outstand (Mainly to avoid their enemies), satyrs will celebrate a great festival during New Year's Eve akin to a bacchanal, to signify their survival of another year in this world.
Harpies: Short humanoids with large eyes with vertical slit pupils, bird wings for arms and feathered digitigrade legs that end on sharp talons. Thanks to their ability to fly, they can travel long distances and settle in tall locations away from enemies, living in tribal communities of hunter-gatherers. Like other fantastical flying creatures (Such as Dragons and Gryphons), harpies can change their gravitational pull and hovering in the air, then using their wings to propel themselves.
Centaurs: A proud and graceful warrior race, trained in the art of archery and strategy. Like in Greek Myths, they are creatures with the upper body of a human (Although having pointed ears like elves) and the lower body and legs of a horse. In ancient times, centaurs lived in herds lead by one or two males, who had a harem of several females, but as civilization progressed, they were introduced to new lifestyles. Now many ''herds'', live in more organized societies where males and females coexist in even numbers, forming sedentary communities and also performing services for other races. Despite that evolution, there's still cases of ''Primal Centaurs'', who continue to behave like they originally did and that means, pillaging small remote villages for mates, food and alcohol.
Merfolk: Aquatic humanoids that present pointed ears, webbed hands, blue scales covering their skin and a fish-like lower body. Like in legends, female merfolk or ''Mermaids'' possess beautiful singing voices and are capable of putting those who hear it on a trance. At birth, merfolk have two tails and these can become legs to escape to the surface from predators, but as they grow and become adults, the tails shall fuse into one capable of giving them high-speed swimming skills. As expected from an aquatic species, merfolk can endure freezing waters, oceanic pressures and even the most poisonous creatures of the sea. When underwater, merfolk communicate with a mix of telepathy and echolocation, creating a sort of ''musical language''.
Lamias: An all-female race of beautiful women with the lower body of a snake. Living in the deserts, they remain neutral until needing to replenish their numbers and will pilgrim to nearby lands, stealing men to breed with them (Later giving birth rather than laying eggs). Living in large communities in the deserts, lamias remain neutral towards other races, until needing to replenish their numbers and will pilgrim to nearby lands, forcing men to breed with them (Later giving birth rather than laying eggs). Albeit lamias don't kill their mates, for some that would more preferable, as they say how mating with a lamia makes mating with human women feels like nothing and will only feel that pleasure again with a lamia. Some lamias are born with green skin and dark hair, being called ''Gorgons'' and armed with a powerful toxic gas released from their eye sockets, which can paralyze those who breath it.
Giants: Most giants look like huge humanoids, typically between 15 and 19 feet tall, but once a generation a few giants reach over 25 feet tall. Unsurprisingly, giants possess immense strength and stamina, they have a resistance against magic that protects them from any enemy spell and even the most deadly curses will not affect them. Giants have access to a form of photosynthesis, which allows them to survive long periods of time without food by feeding on sunlight. As a result of that ability and a ''secondary heart'' (Which helps them flow their blood through their large bodies), most giants can live between 140 and 160 years, in addition to having a less severe aging process. However, their technological levels are not that impressive, they rarely wear armor in battle and use weapons such as clubs and battle axes.
While Magic is real (Albeit rare), there's three major restrictions even the most powerful magic users are unable to break, these being that the past cannot be altered to create a different outcome, the dead shall remain dead (Attempts will just create undead) and to prevent easy fortune, any object replicated with magic shall disappear after one day. Beside these, doing things like conjure things out of the air, transforming into non-human creatures and teleport across the world are extremely difficult and only the most powerful mages can perform them. In most cases, one must be born of someone with magic to use it, but through special methods (Like rituals, potions or magical items) is possible to gain access to it. Despite its power, magic can be easily lost if the bloodline is mixed, since when a mage and a non-mage form a family, it's very likely their children will not possess magic. Instead, magic will become a recessive trait and if reappearing, it happens after a couple generations through atavism.
What do you think of my world? What about yours?
