Starting dimension
Realms of the upper planes: Closest to the realms of Stars, Dreams, Light, Harmony, and Order the upper planes are generally seen as a safer area to colonize then most, but like all realms they have they're own problems and plenty of creatures would see these verdant areas dispoiled to please the forces of evil.
Common Factions: Toads, Angels, Ponies, Dreamlands.
Common threats: Hostile Dreamlanders, Goombas, The Koopa Troop, Changelings, Angels of Jubileus, Dark Matter
Faction Notes: Vampires have a weakness to 'holy' abilities, things that are very common in these realms.
Wallagart: An upper realm closest to the land of dreams Wallagart is a water filled dimension with several island chains and a low number of native inhabitants.
Benefits: High access to aquatic resources, easy access to the dream realm.
Flaws: Massively increased chance of encountering dark matter forces.
Faction Notes: Succubi/Incubi have strong ties to the realm of dreams.
Kallerake: Closest to the realm of stars Kallerake is effectively one giant grasslands, and plays host to several outposts from a peaceful kingdom known as the 'Mushroom Kingdoms' as well as an aggressive kingdom of turtle like beings.
Befits: High access to realm of stars resources, possible early ally.
Flaws: Extremely aggressive and power neighbor.
Rallath: The lowest of the upper realms Rallath is more often then not the first realm attacked by the lower factions, and is also the sight of a great deal of infighting between upper realm armies. Still several natural formations make for great defensive positions and the entire place is great for research. Outside of the easily defended oasis's Rallath's terrain is desert like and desolate due to the constant fighting.
Benefits: Defensible starting areas with a great deal of resources.
Flaws: You'll need those defensible positions.
Vellanus: An upper realm close to both the realms of light and order Vellanus is mostly peaceful aside from fighting between angelic factions. Vellanus's terrain is strange and marble like, an indicator of its proximity to the upper realms above.
Benefits: Bonus to light based research.
Flaws: Increased encounters with the Angels of Jubileus.
Palara: Closest to the realm of Harmony Palara is ironically a large and chaotic jungle. This plane of reality is great for research but inhabitanted by countless monsters both of it's own making and from the realm of dreams.
Benefits: Plenty of unique resources and creature.
Flaws: Large number of monsters, chance of encounter with the Forces of Nature.
The Elemental Realms: Strange realms inhabited by mystical beings the Elemental Realms are the closest to the Elemental Planes, and each of these planes usually posses very large differences from one another.
Common Factions: Elementals, neutral/benevolent nature spirits, benevolent estorics.
Common Threats: Hostile Elements, Orcs, Space Pirates (Kid Icarus), Ing, Murlocs, Undead, Goombas, Darklings, The Forces of Nature, Dragons, Microniods.
Pyros: Closest to the realm of fire Pyros is a planet infested with fire elementals and other flame based creatures, any civilization setting up hear had better be ready for a fight because fire elementals love nothing more then to burn.
Benefits: Rich in mineral resources.
Flaws: High chance of running into fire elementals.
Toxicas: A realm covered in swamps populated venomous wildlife, Toxicas's oceans are composed of poison from the elemental realm of the same name and as such are very hostile to organic swimmers.
Benefits: Bonus to chemical research.
Flaws: Organic units take heavy damage in the water when not in port.
Faction Notes: Once unlocked Hydras (Likely through gaining Casterwill support) and creature with sufficient Hydra DNA are immune to the toxicity of the realm, and may even get a bonus to regeneration within it.
Other: Faction here start out with purification technology and can convert the poisons into fresh drinking water with the resulting structures.
Glacius: Closest to the realm of ice Glacius is a hostile environment with a sparse population and harsh weather.
Benefits: Few rivals.
Flaws: The rivals that do exist are pretty scary.
Faction Notes: If Snow Maidens are unlocked as a backer you basically get a gain to general growth in this realm.
Sallaw: A realm close to the realm of shadows Sallaw is a strange environment that is commonly warred over by the forces of darkness.
Benefits: Unique research options.
Flaws: Increased chance of Dark Matter, Microniod and Ing encounters.
Kzyer: Closest to the realms of the Winds of Magic Kzyer is dominated by several unique environments and fought over by a variety of strange creatures.
Benefits: Several unique resources.
Falws Several unique enemies.
Faction Notes: Your human population has a strange affinity for the winds of magic.
Arraca: Close to the realm of the Arcane the realm of Arraca is a common place of conflict between multidimensional forces. Arraca's terrain is desert like and many strange creatures wander the realm.
Benefits: Bonus to magical research.
Flaws: Increased chance of multi-dimensional invasion, increased chance of encounters with the burning legion.
Luscia: A realm filled with many different forms of life the realm of Lusica is naught but an endless jungel.
Benefits: Bonus to population growth.
Flaws: Your settling on prime real estate and everyone knows it, even foes uncommon to your real have a high chance of making an appearance.
Gravica: A realm of graves and death, in Gravica the dead are restless and the living are slothful. This realm takes the form of a dead forest, desolate and devoid of most life.
Benefits: Surprisingly small amount of hostile factions.
Flaws: Lower population growth.
The Stable Realms: The realms closest to earth the Stable Realms also host some of the greatest wars between 'normal' species.
Common Factions: Reticulans, Crawlers (Normal beyond earth aliens), The Protoss (weaker then cannon) , Eldar (See Protoss), The Covenant, Toads, Ponies, Nerubians.
Common Threats: The Scrin, The Chitauri, Gnolls, The Fallen, Dragons, the Cabal, The Heirarchy, Microniods, Giant Ants(Don't ask how they got off earth), Giant Wasps (Same as the ants), Wargot, The Chimera, The Ethereal Empire, Goombas, Orks, Gobilins, Homeworld Gems (Weaker then Cannon), Trolls, Murlocs, Skaven (Again don't ask how they got off earth), Biomass, Space Pirates (Metroid).
Fungeal: Populated almost entirly by Fungus based life Fungeal is a planet locked in war between two of the most common species in the multiverse.
Benefits: Bonus to health and population growth.
Flaws: Orcs and Goombas everywhere!
Crazack: A realm caught between two alien plagues an enhanced version of Tiberium created by the Scrin and Phazon compete for domination over this planet.
Benefits: Easy acess to potent resources.
Flaws: Your caught in a war between Phazon and Super tiberium do I need to say more?
Qualth: Qualth is a planet covered in stranger organisms with some of the prominent being single celled organisms that have grown far larger then should be natural.
Benefits: Unique research.
Flaws: Heavy Micronoid presence.
Misasu: Covered almost entirly in a strange Miasma Misasu has an extemly heavy Crawl populated and an incredibly alien environment.
Benefits: Bonus to base Harmony Path
Flaws: If you tick off the crawlers expect to be swarmed.
Swath: Covered with biomass on one side and Miasma on the other Swath is a plenty fought over by Biomass life forms and Crawlers in a struggle for domination.
Benefits: Threats to focused on earth other.
Flaws: Most of the inhabitable areas are stuck in between said threads.
Grow: One of the first areas discovered by earth Grow is a rocky planted filled with underground tunnels. When the Giant Ants and Skaven first broke off from earth this was one of the first places infested, and the two war over control of the planet with Night Goblins and Nerubians to this day.
Befits: Heavy access to mineral resources.
Flaws: A heavy Skaven presence with all that entails.
Radac: Another realm discovered early by Earth Radac was the sight of a war between early human colonists and the Hierachy. The resulting conflict left the surface of the planet choked with radiation of both types and deserted settlements around.
Benefits: Not widely sought after, infrastructure that only needs a bit of radiation scrubbing.
Flaws: Hierarchy Remnants are present in force.
Mieral: A resource rich and rocky realm Mieral is fought over by Home world Gens, Skaven, and the Heirarchy all of whom seek to claim it's bountiful resources for itself.
Benefits: Resource rich.
Flaws: Large number of warring factions present,
Culuk: An artificial realm created by the NOVA builders Culuk is a world of endless machinery, and opportunity.
Benefits: Plenty of ruins to explore.
Flaws: Infested with Protoss and Covinant fanatics.
Alat: An earth like planet Alat is a relatively peaceful and out of the way location.
Benefits: No outstanding flaws.
Flaws: No outstanding benefits.
Eleden: An extremely lush realm Eleden is a realm that is sought over by many rising empires.
Benefits: Extreme bonus to population growth.
Flaws: Extreme competition.
The Lower Realms: Extremely close to the infernal Realm the Lower Realms are about as hostile as an environment can get while still being inhabitable by normal life, and us infested with a wide variety of malevolent life forms from the lower reams to boot.
Common Factions: Non hostile Goombas, Some Mutant Minion Tribes.
Common Threats: The Forces of the Chaos Gods, The Burning Legion, The Forces of the Abysse, Dark Matter, The Underworld Army, The Darkness, The Legions of hell (DOOM), The Nine Hells, Skaven, Gnolls, Goombas, Minions, Darklings, Ing.
Faction Notes: Youkai are stronger in these realms, youkai are resistant to corruption.
Velen: A realm equally distant from all of the infernal realms Velen is a frequent sight for battles between a variety of infernal forces.
Benefits: No infernal forces will focus on you.
Flaws: You'll be besieged by a much wider variety of infernal forces.
Muka: A planet crawling with mutants the most common 'normal;' inhabitants of this place are followers of the chaos god of change.
Benefits: Plenty of research options.
Flaws: Lots of angry mutants.
Plcas: A plain infested by plague Plcas is a prime place of worship for the Chaos God of disease, as well as the Skaven who thankfully hate the Chaos God in question.
Benefits: Bonus to research about disease.
Flaws: Penalty to population growth.
Warrac: A realm covered in the powerful fellstones Warrac is fought over by the Skaven and burning legion, both of whom want the valuable resource for themselves.
Benefits: Easy access to a valuable resource.
Flaws: Said resource is incredibly dangerous.
Bloodwell: A realm close to the domain of the blood god and Hell itself this place is often besieged by both factions, who care not for any resources within, but for the simple act of carnage itself.
Benefits: Easy combat experience.
Flaws: Almost no chance at peace.
Grula: A somber realm Grula is covered in wayward souls from the the realms above and as such is heavily contested by the Underworld Army, The Abyss and the Nine Hells all of whom want a cut of the soul profit. Dark Matter, the Ing, and the Darklings are also known to be more common then average here.
Benefits: Bonus to soul research.
Flaws: Like most realms expect a lot of combat.
Xellex: A realm of oil and metal Xellex is research rich and out of the way a good combination for 'normal' settlers of the lower realms.
Benefits: Massive resources, lower amounts of demons,
Flaws: High chance of Skaven and the Hierarchy.