Made by Illwinter Game Design and Shrapnel Games. An unusual Turn-Based Strategy game series in the classic 4X style. Fourth game Domions IV: Thrones of Ascension was released December 5, 2013. In the wake of the apparent death of the one true high god, various entities (Pretender Gods) attempt to attain the vacant position through the expedient method of wiping out all competition.Dominions is a turn-based game on the continental scale, but a very extreme form of simultaneous resolution for tactical battles: You aren't actually allowed to give any orders when battle (and sometimes hilarity) ensues. Instead, you can only give standing formation and conditional tactics orders to a unit of soldiers in the strategic view, then sit back and hope for the best whenever they come into contact with the enemy. This allows the game to be played by email, or over longer periods of Real Life time.Not to be confused with the Board GameDominion or the tv show Dominion.
Dominions provides examples of:
All There in the Manual: There's very little in game documentation for the basics, including an instructive tutorial. But the manual is incredibly useful (if wildly inaccurate at times — read the forums, seriously!)
Amplifier Artifact: Many magical items help their user cast magic, reinvigorate them or can provide a penetration bonus against their targets' Magic Resistance.
Angels, Devils and Squid: All three make an appearance, particularly as summonable beings, alongside a variety of celestial or infernal beings from other pantheons. Angels tend to be associated with Astral magic, and Devils with Blood magic. The Squids meanwhile get their own faction, R'lyeh, which is exactly what it sounds like — a realm ruled by eldritch beings that spread madness wherever they go.
Animate Dead: Death magic allows mages to create and command undead. Also undead priests have the ability to create zombies, ghouls, skeletons, etc based off of their priest level.
Artificial Stupidity: The AI is simply not able to handle a lot of the game's complexity. As such, it will mostly just try to bury you under waves of national or provincial troops.
Ancient Tomb: Some Magic Sites are Ancient Tombs. Also, one might be found in a random event, which can provide both gold and a magic item.
Annoying Arrows: Most of time a single arrow will kill an unarmoured human. Tower shields, heavy armour and certain spells can turn them into their annoying variants.
Artifact of Attraction: Certain magical items can provide negative effects and some of them are cursed, meaning that there is no way of getting rid of them.
Artifact of Doom: Gift of Kurgi, which provides sizeable physical powers but destroys its carrier's mind.
Pretty anything with a chance to inflict a horror mark or insanity, however special mention goes to the Dimensional Rod, the Boots of the Planes, the Tome of High Power, and The Horror Harmonica. Almost all of them require astral or Blood Magic to forge.
An Axe to Grind: Many, many troops carry axes and magical variants can also be crafted.
Barbarian Tribe: Early Era Ulm, Marverni and Sauromatia are nations that are examples of this. In the Early Era most independents are barbarians as well. Some random events can cause barbarians to attack one of your provinces.
Back from the Dead: Pretender gods can be called back, immortals only die permanently outside of your dominion and spells can be used to revive commanders who made it into the Hall of Fame.
Arguably Late Age Ermor and Late Age Ryleh could also be considered strong candidates for this trope, with seemingly endless undead hordes coming from the former and Lovecraftian astral horrors from the latter.
In Dominions 4, Lemuria takes over Ermor's Dominions 3 role in the Late Age (Lemuria's undead are ghosts instead of skeletons, but it's still undead legions with a descent hailing from the old empire of Ermor). In the Middle Age, Ermor is definitely this — it is like the Late Age Ermor of Dominions 3 (the role played by the old Middle Age Ermor is taken up by Sceleria, a splinter empire of Ermor), and was (as revealed in Late Age nations descriptions) the arch-enemy to two other nations — one of which ended up doing a Deal with the Devil to gain the power to actually bring down Ermor.
Black Cloak: Various Blood and Death mages wear these. Interestingly enough, so do Marignon's Friars.
Blood Magic: Involves hunting down special virgins to sacrifice for magical power. Or, for the particularly crass,powerful magic items.
The Call Knows Where You Live: If a unique unit is wished for by another nation, the unit will be transported to their laboratory no matter where it is. Your own version of the unit will then go poof.
Clap Your Hands If You Believe: Although there are a few sacred units that can be recruited on the map or through summons, by and large they are Sacred because your nation's population believes they are — lore-wise, that is. Mechanically it is just a matter of putting the "holy" tag on a unit.
The Machaka Colossal Fetish is a mindless "god" that came to life after hundreds of years of worship and does whatever its worshippers believe it would do.
And then there's the titular concept: the more the people of a given region believe in you, the more you influence what happens there. Conversely if there's nobody left in the world to believe in you because everyone's converted to another religion it's game over, man.
Corrupt Church: Late Era Marignon. They've abandoned their Knight Templar roots, since it's cheaper to pay the Infernal Lords off with blood sacrifice than to wage a neverending war to keep their society pure.
Crapsack World: Dominions 3's Late Era. More and more factions are using death and blood magic. Ermor has become a realm of the dead. Ulm is a realm of vampires and wolves. R'lyeh is a land of insanity and death, where the Veil between reality and the madness of the Void is breaking down. And then you and the rest of the Pretenders come along and start unleashing supernatural monsters and undead horrors over the land. Not to mention that magic is fading from the lands as a whole.
That said, there's evidence that this is a A World Half Full. Jomon has fully thrown off the grip of their Oni oppressors, and Patala is just on the cusp of a Golden Age under the benign rule of the Naga. Humans are also gaining ascendancy in other kingdoms as well, by virtue of the fact that their divine protectors / oppressors are growing less powerful and numerous as a result of the magic gradually fading from the world. Capitalizing on that hope depends on who wins.
The Early Age is a hellish world for a different reason. The magic of the world is in full bloom, completely untamed by human hands, and those without magical powers or enhancement are helpless before terrible creatures that prey on them freely. The humans themselves are often little better, from the Androphags of Sauromatia to the savage, blood-sacrificing Druids of Marverni. And the greatest bastion of human strength in the world, the New Faith of Ermor, is destined to become the Ashen Empire.
The Middle Age is less of a crapsack, without any of the truly horrific evils of Early or Late, but that doesn't make it a nice place by any means. Here, you see where many of the terrible evils of the Late Age started, most notably the decline of Ermor.
Dominions 4 is basically the same, though with some details different — the Early Age gets a bit more positive (Ur is building a civilization without any overt evils, and Berytos is relatively non-bad for a civilization that has fallen under the influence of a blood cult), the Middle Age gets one more horrific evil (Ermor is already its Dominion 3 land of the dead incarnation — though the splinter empire that covers the Dominions 3 Middle Age Ermor territory is presented in a more positive light as well), and the Late Age is pretty much the same, except 'Ermor' is called Lemuria and the dead are ghosts (Ermor got destroyed, but the aforementioned splinter empire managed to repeat some of its mistakes. Oops).
Crutch Character: Pretty common. Niefel Jarls come to mind: they're awesome bless rushers, but if you have nothing but Niefels in the late game, they'll be overwhelmed.
The community term is "thugs," which refer to easily-recruited low-end One Man Armies. Highly useful in the early and midgame, but they don't usually have the staying power to fight the real Super Combatants that get summoned in the endgame.
Crystal Ball: There are are both items and spells that allow Scrying. Also, certain magic sites provide the ability to Scry.
Dark Is Not Evil: Explicit in some units, such as the C'tis Sauromancers, who practice the magic of death responsibly. Implicit, if you're a particularly Nice God who just happens to have undead generals. Can be argued to be the case even of Mictlan's virgin sacrificing priests. Generally not the case in the The Late Age. Definitely not the case for Late Ermor and R'lyeh (or Mid Ermor and the Late Age Lemuria in 4).
The embodiment of this would be Well of Sorrows, a world spell that creates Death gems by siphoning all the misery and pain in the land into the Pretender's body, resulting in death, disease, and old age being much less painful. The congratulatory text implies that this is a minor Heroic Sacrifice on your part.
The Determinator: By the Late Age, Atlantis has suffered two civilization-ending apocalypses and are now teetering on the brink of ruin. What do they chose to do? Train special insanity resistant units for the specific purposes of grinding R'lyeh into the dirt.
The Dev Team Thinks of Everything: One of the Arcoscephale Commander Units is the Heart Companion, their description says they work for the preistesses of the temples and fight alongside their brothers and lovers. In otherwords they are gay. As a result they are immune to seduction.
Did You Just Punch Out Cthulhu?: Can happen with pretender gods, if they die particularly ignominiously. Particularly embarrassing is losing to blood slaves... which are roughly the weakest unit in the game and really only exist to give Blood Mages something to sacrifice in combat.
The way the damage calculations work is that a 'die roll' from 1-6 is made. Every time the computer rolls a 6, it makes a another roll, adding the result to the damage total. This means that it's quite possible, though extremely rare, for "David and Goliath" events to occur, where, say, a lowly militiaman with a sling kills a dragon with a single hit.
Also with certain mods that allow you to pick Cthulhu as a Pretender.
Divine Conflict: The games have a variant of this. You're one of a number of pretender gods, all warring against one another to become the one true god.
Dual Wielding: Several troops. Of particular note are Early Tien Chi's sacred kung fu masters, although technically any unit with two or more arms can wield multiple weapons (or shields). Dual-wielded shields are a semi-popular tactic for kitting out thugs, who need the survivability more than any actual ability to kill things.
Easy Logistics: Strongly Averted. There are tons of ways to circumvent the supply or resource limit — but all of them are expressly magical. However, arrows are always free.
While each province has it's own supply limit that can't be manually transferred, fortifications send out supplies to nearby provinces, with those farther away receiving less. This being in addition to greatly increasing the supplies in the province of the fortress.
Eldritch Abomination: Multiple kinds, actually. R'lyeh is in the service of the Great Old Ones from beyond the stars, while the spell "Horror mark" allows you to draw Soul-Eating Starfish Aliens from the Astral Plane to attack your enemies' commanders, the most powerful of which are the brutal Doom Horrors.
In the Early Age, the Star has not fallen, and R'lyeh is instead ruled by the aboleths, a race of Time Abyss sea creatures that dominate the minds of the lesser aquatic races.
Elemental Embodiment: Each of the elements (Fire, Water, Air, Earth) have six different sizes of elementals and royalties (Queens for Water and Air, Kings for Fire and Earth) to be summoned.
Elite Mooks: Many nations can recruit soldiers that are the best of the best mortal races can provide. This doesn't really raise their life expectancy by a lot.
The Empire: Any state ruled by a Pretender God, but in terms of the lore, Ermor between the Early and Middle Ages was a quite successful example, with no less than five successor and break-away states confirmed after the First Fall of Ermor (the now-undead Ermor itself, the splinter empire Sceleria, Pythium (which rules over the territories that were once Sauromatian), Marignon (the province that once had the Marverni tribes) and Ulm).
Every Japanese Sword Is a Katana: Surprisingly averted. Although there aren't the many variations listed, there are still Wakizashis for most of the villains, tanto for Late Age Ninjas, and Tachis and Nodachis for some of the bigger Oni and Bakemono.
Evil Is Not a Toy: Wishing for a Doom Horror will give you one with a 50% chance of it turning against you. The Eater of the Dead, if allowed to consume enough corpses, will eventually break your control.
Evil Versus Evil: With certain nation combinations this is unavoidable. Also, most of the really powerful endgame summons aren't exactly nice folk.
The Fair Folk: Many nations boast summons and recruitables that fit this role. Also, you can summon actual Faerie Queens, plus entourage. Finally, the nation of Tir Na N'og (added in an early patch) is based on that particular mythology, with Sidhe commanders, banshees, etc...
This applies even more strongly to the Norse nations of Helheim and Vanheim, considering their use of Blood Magic and Human Sacrifice.
Face-Heel Turn: Mind control spells force this on units that fail their magic resist roll.
Fallen Angel: The generic fallen angels Late Era Marignon can call, and the Grigori that Early Era Hinnom can obtain. Both are released from their hellish prisons by blood sacrifice: of particular note, releasing even one of the six Grigori requires the largest single sacrifice of blood slaves in the entire game.
Fantasy Counterpart Culture: Applies to every nation in the game to a certain degree, some more, some less. The rest are mostly Fantasy Counterpart Cultures to other well-known fantasy cultures. However, one big difference is that these cultures are not necessarily human; both the Norse and the Canaanite cultures, for example, are giant races (at least until Late Age, where both cultures are mostly composed of assimilated humans).
Fantasy Kitchen Sink: Nations draw from pretty much every imaginable mythological source. As a result, a war between, for example, the Nephilim of Jewish apocrypha, the Fair Folk of Irish legend, and Japanese oni is pretty par for the course.
Feelies the game's manual is over 300 pages thick.
Fisher King: The properties of a province (such as crop growth, or ambient magic) will change depending on which Pretender has dominion over it. Some dominions may even change the terrain type.
Fish People: The Ichthyids independents and Atlantians.
Flaming Sword: Fire Brand, which is literal flaming blade. Frost Brand burns with cold flames, Shadow Brand burns with shadow flames and Demon Whip is burning whip. There is also a Flaming Arrows spell that applies this effect to your archers and if you build your pretender right you can apply it to your sacreds.
Foe-Tossing Charge: The Trample ability allows units which have it to crush smaller units that fail to resist it and displace the rest.
Frazetta Man: Hinnom's Horim in the Early Age are Frazetta Giants. There are also the independent Cave Men.
From Bad to Worse: Ulm, Pangaea, Atlantis, R'lyeh, and Ermor (the later of which has gone straight to hell... and then came back to murder everybody else).
God Emperor: The pretenders are basically this to their respective nations. In addition, according to the description for the Divine Emperor pretender, the nations for which it is available used Roman-style post-death deification before the Divine Emperor leveraged the technical status as a Son of God that granted him to become a pretender god (and therefore immortal).
Gods Need Prayer Badly: The faith of people in various provinces is represented by a candle. This affects the knowledge you have of the province, the level at which you can affect it and, should you move it into the area, the hitpoints of your Pretender God. Any God who loses all their belief is eliminated from the game.
Then again, considering that regions with 0 population can still hold dominion, and omnicidal factions like LA Ermor and LA R'yleh thrive on them, it seems that dominion involves a more generic "divine influence" rating rather than outright popfaith.
Grey and Gray Morality: With some Black thrown in, like Late Age Ermor. No single faction is unambiguously good, and all of them have the potential to research and use spells with horrible effects.
Half-Human Hybrid: Many nations that have both fantasy races and mortal races boast half human hybrids.
Have You Seen My God?: The whole reason for the Ascension Wars is that the old Pantokrator, the supreme god of the setting, has vacated his post for reasons unknown, opening the way for other divine powers to fight over the top spot themselves. Constant references to "a previous Pantokrator" (rather than "the previous Pantokrator") imply that it's happened at least once before, as well.
Hell: You have the Inferno, a realm of fire, Kokytos, a realm of ice, an an unnamed realm of darkness, an unnamed realm of storms, an unnamed realm of something. There's also Tartarus, which acts as a prison for defeated pretenders.
Hero Killer: The Hunter of Heroes is one of the beings that will deal with especially stubborn horror-marked units. Give that it's a Doom Horror, it's quite up to the task.
He Who Fights Monsters: Late Age Marignon's hat. In order to fight the threat of the malevolent undead of Ermor, they started making pacts with demons.
Hidden Elf Village: Various magical sites provide recruitable units, but most of these must be found by magical searching before they provide their secrets.
Horny Devils: Blood nations can summon Succubi and various other seducers from Hell. Notably, one of the Demon Lords can seduce both men and women.
Horrifying Hero: Your pretender can be a manticore, a skeletal dragon, a two headed serpintine dragon, a vampire, a giant, flaming head, a scorpion centaur, and other even more bizarre entities. Of course, the 'hero' part is largely dependent on your playing style...
Ho Yay: In-Universe, Middle Age Arcoscephale's Hearth Companions, who are big gay Theben men, are described as "liv[ing] and fight[ing] side by side with their lovers and brothers-in-arms". They also can't be seduced.
Hyperspace Is a Scary Place: The travel spell Stygian Paths allows travel to distant provinces, but exposes anybody doing so to attack by the spirits of the dead. Also, beyond the Veil lie the realm of Horrors.
The nature equivalent Faery Trod uses paths of faeries rather than the dead but is no safer, with soldiers being lost forever in the magic forests on the way.
An Ice Person: Nifelheim's frost giants, the Frost Devils from Cocytus, and the Eskimo-influenced Atlantians of the Late Era. The winged people of Caelum also fit the bill to some extent - while their magic mostly revolves around lightning, they wield weapons and wear armours made of ice. Magic ice.
I'm a Humanitarian: Very common, but special note goes to the Rephaim and Nephilim of Hinnom. They eat giants.
Immortality: Units with the immortal tag will resurrect in their capital if they die - provided they die in friendly dominion.
Jerkass Gods: This can certainly apply Pretenders, but it seems to have been the case for the previous Pankrator as well. A number of Pretenders' backgrounds involve them being sealed away by the Pankrator for perceived slights or simply because they were no longer useful.
Keystone Army: An army comprised principally of the undead, demons, or other magical beings can be this. Without any commanders capable of handling them, they will either rout, or fall apart. Never, ever attack an army of mind-blasters with an army of mindless undead unless your commander is also a mindless undead.
Let's You and Him Fight: Some rare spells don't technically summon allies. They just add a third side to a particular battlefield.
Like a Badass out of Hell: Being banished to the Inferno or Kokytus is not necessarily a one-way trip — powerful (or just plain lucky) units can escape.
This is also basically what Tartarian Gate does.
Light Is Not Good: And how! Astral Magic, among other things, can allow the mage to lobotomize the subjects of an enemy Pretender and force a rebellion among the populace. Astral Magic is also the magic that one uses to call forth Horrors.
Horrors need astral magic coupled with blood magic though, so it's kind of a mixed case about those horrors.
Linear Warriors, Quadratic Wizards: Acknowledged in the manual and intended. Although melee combatants can use some pretty incredibly powerful magical equipment, ultimately magic will be the decisive element if the game goes on for any extended amount of time.
Lightning Bruiser: Most giants, especially the ones with armor. Not as fast as cavalry, but much faster than equally well equipped humans.
Giants don't generally have a better to-hit or number of attacks than a comparable human unit. Perfectly applicable to high-end summons, though, which are tougher, smarter and more agile than any regular unit.
Living Statue: The sacreds of middle age Agartha are this, also some summons. But not the Chekhov's Gun version.
Make a Wish: "Wish" is a high-level spell, giving you roughly whatever you wish for, with some dangers if you're too ambitious.
The Magic Goes Away: As Eras change, both the number of magic sites and the number of magically powerful national troops decreases. Several factions that were originally composed of nonhuman races become predominantly or exclusively human, though their cultures remain influenced by the magical races that they replaced. Also, if a pretender god has magic draining scales, magic gems might lose their power in a random bad event.
Mineral Macguffin: Magic gems, which are generated by magic sites and have a variety of uses, either in casting ritual spells, forging magic items, or helping mages "power up" their spells in battle.
More Dakka: T'ien C'hi utilizes a myriad of bow-users, including cavalry. Using hundreds of them can be an impressive sight.
Names to Run Away From Really Fast: Late Age Ermor has an enormous amount of these. A quick grab out of a current game: Leprosy, Carnage, Childslay, Venomspew, Plaguestorm, Hopevoid, Quickdeath, Soulrend, Skullbreaker and Wormfeast.
The doom horrors that will hunt creatures with especially strong horror marks are: the Abomination of Desolation, the Eater of Dreams, the Eater of Gods, the Hunter of Heroes, the Maker of Ruins, and the Slave to Unreason. All are aptly named.
Depending on his or her titles, a pretender can be an example.
Nature Hero: Sort of the point of Early Age Pangaea. Wild Man seems more fitting.
Also quite a bit of Hinnom. Jewish Giant Cannibal Mages.
Ermor: Ancient Undead Roman Ghosts.
Pythium: Ancient Byzantine Hydra Tamers.
Late Age Atlantis: Water-Breathing Eskimo Necromancers.
The list goes on and on, really.
Obviously Evil: Late Age Ermor and R'lyeh. Various pretender gods as well. And the various breeds of demons, of course.
Omnicidal Maniac: Late Age Ermor and R'lyeh, again, both of whom slowly kill those in their dominion. Ermor seeks a world ruled utterly by the undead, while R'lyeh wants to haul the world straight into the Void.
One-Man Army: Given some time, experience and magical equipment, your pretender god can grow from a powerful unit into what the community terms a "super-combatant". When you've put enough time into the game to appreciate what constitutes a large army (more than 200-300 living soldiers are difficult to field without either magical assistance or constant starvation) and have become resigned to the inevitability of attrition in any significant battle, few things are more satisfying than seeing an after-battle report like this:
Enemies killed: 378 of 574. Friendlies killed: 0 of 1.
Most triumphantly, the legendary Neifel Jarl. One such giant, with the proper blesses, can go forth and slaughter the independents of the world, in a weird inversion of the Zerg Rush. (Once the game gets going, they can become Awesome, but Impractical due to lack of numbers.)
Person of Mass Destruction: High leveled mages can, with the research to go with their skill, annihilate or simply dominate the minds of armies consisting of hundreds of soldiers. With some preparation time (one turn/month) and the majority of magical gems in your nations treasury, make a second sun to screw up the races who aren't used to heat, plunge the world into eternal night, accelerate time to kill all living beings in a few years and call on armageddon.
Physical God: While pretenders are "only" fighting to become the new true god, many of them have magical powers capable of creating another Sun, or plunging whole world into darkness or doing magic mortal mages can only imagine.
Professional Killer: Some nations can recruit assassins while everyone else can get access via various Magic Sites, mercenaries and summonables. Also, every commander capable of stealth can be turned into an assassin through the Black Heart, at the cost of getting a permanent Affliction.
Our Demons Are Different: There are five basic units that can be summoned, devils, frost devils, strom devils, fiends of darkness and demon knights, not including the various nation-exclusive summons.
Powered by a Forsaken Child: The fountain spirit Pretender Gods apparently demand that a little girl be blinded and possibly crippled (rendered unable to do anything but speak) so that the spirit can give commands through her. When she reaches 13, they kill her and get another little girl. Makes you want to play one of the nice gods, doesn't it?
The Power of Blood: Can have some of the most intense spells in the game, at the low low cost of hundreds of virgins.
Religion is Magic: Divine magic, which is only accessible to holy commanders, i.e. priests.
Right Under Their Noses: Most magic sites must be searched and found before their effect, be it magical gems, gold, recruitable mages or cheaper magic can be used. Negative effects are always active.
Some pretender gods are Stealthy, meaning that they could be hiding in an enemy's capital without them knowing.
Royals Who Actually Do Something: While some nations' royalty cannot be seen anywhere (probably because you took over their job), other nations' royalty can be seen to be excellent warriors, great generals and powerful mages. A few nations have the Divine Emperor pretender available, who is both the legitimate monarch and a pretender god (his claim to pretender-hood is based on his father, the old emperor's, post-death deification).
Sealed Evil in a Can: The spell Tartarian Gate allows you to summon dead gods imprisoned in Hell. An imprisoned pretender can fit too.
Blood magic spells that summon unique Arch-Devils, Ice Devils, Heliophagii and Demon Lords also count.
Ermor's lore in 3 is basically this, too. In the Early Age, Jesus just died and they're spreading his message. In the Middle Age, they tried to resurrect Jesus but messed up and released Death instead. Not the concept, the entity. A new religion, the Death Cult, tries their best to keep Death contained, more or less by channelling it into lots of undeads. By the Late Age, the Death Cult has mostly failed, Death is loose and, well, give it half a year before the entire population of Ermor is completely wiped out. And that of all the lands around it, to be replaced by an endless stream of undead.
The Rimtursar ice-giants. They can't be fully unsealed within the context of the game, but even opening the can and starting to reawaken them is enough to bring about a Class 1 Apocalypse How.
In the expansion patch, the Grigori, the ancient Lords of Civilization who sinned by mating with the Avvim giants.
Siege Engines: While most mundane siege engines cannot be seen, some nations can recruit siege engineers to help bring walls down. Magical siege engines, Siege Golems particularly, can be very effective during both sieges and battles.
Slave Race: Humans serve this role in a number of different factions, particularly in the Early Age. Their divine masters traverse the entire spectrum from benevolent to abusive. As the ages pass, humans begin to gain more independence, either (rarely) by an explicit takeover or (more commonly) simply by default as their former masters decline in power and numbers.
Suffer The Slings: Slingers are available as the cheapest, weakest form of ranged unit. The C'tissians use poisonous bullets that explode on impact for extra effectiveness.
Summon Magic: Temporary summons that only create allies for the duration of the battle, and permanent summons that last until they die — or even longer.
Surveillance as the Plot Demands: The global enchantment spell The Eyes of God allows the caster to see detailed information about provinces outside his or her dominions. Inside it's even more effective, giving reports on hostile armies and reducing the effectiveness of enemy stealth and illusion. All for the low price of fifty astral pearls. It can be countered by...
Technology Levels: Rather than researching individual spells, factions research levels in different schools. Whether or not a particular mage can cast a particular spell depends on their individual skill with the required path(s).
There Can Be Only One: Only one pretender can ascend to true divinity. The game mechanics literally do not allow for allied victories.
In 4, a new game mechanic has been introduced that allows for allied victories. Still can be only one, since it involves pre-existing alliances where all players except one play as 'disciples' instead of a Pretender God (your Dominion is for most purposes your master Pretender God's Dominion. On the plus side, that does mean you can put all your points (which are just as many as for Pretender Gods) in making your Disciple powerful instead of diverting some to modifying your Dominion's effect...). Story-wise, only the Pretender ascends to true divinity, while his/her Disciples presumably gets rewarded for their loyal service with power and influence.
The Time of Myths: Ages long past, often referenced in spells, which summon creatures common in that time. In the Late Age, the Early Ages of some of the nations can feel like this.
Top God: The Pantokrator used to be one. His disappearance opens the way for the newly-free Pretender Gods to compete for the spot.
The Undead: Most of the entries on this list (and then some), though Frankenstein's Monster is simply a souped up zombie.
You Require More Vespene Gas: Gold, which is global to your empire, and the abstract 'Resources', which represent the ability to make things. Gold generally represents the cost to train a unit and it's raw statistics, Resources generally go up with armor and weapons and represent survivability.
Unusable Enemy Equipment: Averted with Commanders, whose magical equipment (partly) drops on death, and played completely straight with the rank and file. Not that their stuff would be very usable, after some of the spells you can sling.
Video Game Caring Potential: It's amazing the lengths you can go to keep your particularly famous commanders alive. Also rank and file who have reached the third experience level. A number of global enchantments such as Fata Morgana, Well of Misery, and Gift of Nature's Bounty are geared towards making the lives of your subjects easier.
Video Game Cruelty Potential: Aside from pillaging and blood sacrifice, there are some truly nasty spells that you can use. Raging Hearts, Tidal Wave, Hurricane, and Volcanic Eruption all come to mind.
Warrior Prince: Middle Era T'ien Ch'i can recruit Prince Generals. C'Tis has Lizard Heirs to go with their Lizard Kings.
We Can Rule Together: Averted. While temporary alliances and co-operation are pretty much needed to win multiplayer game, there can only be one victor in the end.
In 4, there can be multiple victors, but alliances are set-up in advance, and storywise only one player gets to be top dog and ascend to true divinity — the others are his/her/its disciples, who presumably get rewarded with power and influence after their master ascends.
We Have Reserves: Some units are only useful to wear down enemy units and be killed in large numbers. This is particularly true of units that spawn for free in your provinces (the undead of Ermor, Polypal Spawn for early R'lyeh).
Wheel of Pain: In Dominions 3, Early Ulm has it as one of their national sites. Orphans are sent there, and those who survive are made into Steel Warriors, often called "Conans" by the fans.
When Trees Attack: Nature mages can recruit Treants and various other tree people. Pangaea can summon units made from roots and other foresty bits (including tree zombies).
Whip It Good: Some mundane units (mostly slavers and flagellants) wield whips and there are some magical whips as well.
Wizards Live Longer: Most mages start noticeably older than other units, some have much longer life spans and others just don't die. Averted with Fire mages, who actually lose maximum age as they grow in power.
The embodiment of this trope would be the Crone pretender, who starts out at 650 years of age.
You Can't Fight Fate: Horror Marks and Curses cannot be removed by any means. While neither is immediately lethal, Horror Mark summons Horrors that will cause more Horror Marks, meaning more powerful Horrors. Sooner or later the carrier of Horror Mark is killed. Particularly unfortunate if the poor bugger is your pretender god, because even death won't remove the mark.
Zerg Rush: Generally averted or inverted. Due to the way combat and morale work, using large numbers of weak units generally means they get slaughtered and cause your better units to rout with them. The standard rush tactic is the bless rush, which uses a small number of divinely empowered elites.
Sort of. It's both averted, in that the rush strategy involves elites, and played straight. Each iterative attack in a turn penalizes the enemy's defense and attack (For purposes of repelling enemy attacks), so if you have enough cheap units surrounding their experienced sacreds, you stand a good shot of killing one.
Also, played dead straight with undead armies. Since mindless undead are immune to morale effects and can be created by the bucketload, you can literally send multiple armies of thousands each to their destruction without having them break. Less effective than it sounds, though, since your average longdead has 4 hp and no protection worth mentioning (the basic human militia has 10 hp). Only really works against independents, early in the game.
Zombie Apocalypse: Ermor by the Late (in 3) or Middle (in 4) Age is the embodiment of this trope. 4's Late Age nation Lemuria is a Ghost Apocalypse.