Why would a race with high longevity but low numbers be aggressive and warlike?

Question

Context

Members of my race can live virtually infinite lives (they still have to drink, eat, and can be killed, but don't age and are immune/really resistant to disease) but are unable to reproduce.

They used to be "manually" created by a god, who has not manifested since hundreds of years ago, thus not giving birth to any new member of this race ever since.

Question

However I feel like this applies to pretty much any long-lived-but-slow-at-reproducing race (such as classic Tolkien-like elves), so the matter is more general:

Why would a long lived race decide to wage war and fight others, knowing that (regardless of the outcome) they will be losing many more people than they will be able to give birth to in a long time?

This seems pretty common in fantasy, but I feel like such a race would be much more sensitive towards even the smallest losses, since their low fertility makes extinction a potential risk.

I want to know what good reasons this race would have to enter a war or generally have high aggression (not only the obvious ones like being forced to choose between a defensive war and annihilation), because I would like the race to be fairly warlike despite the risks.

To be clearer about what I mean with "having a reason to fight": for example, one idea might be having the god create them with an innate instinct to fight (like Orcs and Half-orcs in D&D, for example) but I'm afraid that would sound too cliché. I don't want them to be utterly self-destructive, since they would go extinct in a matter of years, just prone to and good at fighting.

Answer 1

They're immortals, they've had thousands of years to hone their skills. They don't die easily. They're all veterans of countless battles and know when to retreat. For humans losing mere dozens out of thousands in a pitched battle is a fantastic success. For them even one or two losses is a rare and sad event.

Any normal attrition rate would leave their numbers depleted too fast.

So, with that in mind there's quite a few options...

Give them something to gain from battle

They are immortal, yes, but over the eons the life force inside them slowly stagnates. It will never kill them but life becomes a dull grey as the centuries wear on. How can they negate this slow dulling of the world? With vivid and extreme experiences, fear, sweat, blood. Or perhaps they can sap a trace of the spiritual energy away from a foe defeated in honorable combat to invigorate their own and bring colour back into their experience of the world.

Which could be used as a mechanism to effectively make them need battle every few years/decades/centuries even if they're demure peaceful artists much of the rest of the time.

Race of paladins

They are the product of a god, heretics are inimical to their very souls and must be destroyed

They remained at peace for a long time... until heresy spread through neighboring kingdoms. Now with the righteous fire of their convictions burning through their veins they are overwhelmingly compelled to crush the unclean heretics who would abandon the ways of their god.

War as suicide or extreme sport

The very very old get bored and lose their love of life.

As is the tradition of their people taking their own life is seen as an affront to their gods gift of life and dying at the hands of a weakling would shame them. So they go to war until they meet an opponent who can defeat them without it shaming them.

Answer 2

As have been mentioned by @Murphey and @Twelth, war can be a relief of boredom and they will be very good at it.

As other people have mentioned, I can't believe that they would form a battle line and go numbers to numbers against a foe. They would use all of their skill that they've developed.

Also, there might only be one or two in a battle. They run in from a sideline and kill a bunch and then leave. Or they sit back and pick off people with a bow.

You might have one each on both sides of the battle in a contest with each other. They wouldn't fight each other but would be keeping score. To make things interesting, they might put restrictions on themselves like: only arrows through the left eye count.

They would make awesome: scouts, assassins, and generals.

Imagine two immortals playing chess with real people.

Heck, they are probably playing Settlers of Cattan or Risk with nations. Then, when they get bored, they join a fight and put enough restrictions on themselves to make it interesting.

Answer 3

They don't die the way we do

Your fantasy/scifi races are under no obligation to resemble anything on Earth. You and I have all these fleshy organs arranged in a delicate balance that can be upset in any of a million ways - we seem to cease to function at the slightest provocation. Your race, however, may not.

Perhaps they have one of these features;

• They have bodies with total regeneration. They can (with time) regrow limbs, organs, bones, everything as long as their "brain(s?)" remain intact. You and I fear amputation and dismemberment, these guys can fight with no regard for losing some pieces here or there - because if even a small part of them survives they can regrow good-as-new.
• They go into advanced hibernation. Maybe to your guys "death" is merely a hibernation state in which their body slumps over, but can be easily revived by a healer. It would have to be extremely difficult to actually destroy their brains (or, souls, or whatever); perhaps the only thing that can truly destroy their "essence" is a specific acid that's difficult to make (depending on how hard or soft your magic/science is).
• Death is a normal part of life. Plenty of animals on Earth go through some pretty excruciating procedures that involve totally destroying their old bodies in order to construct new ones. Maybe your race needs to be killed so that they can be magically reborn in the next phase of their life.

It's worse if you kill them

Nature has a lot of relationships between species that is symbiotic at best, parasitic at worst, and usually somewhere in between. The same might be true for your race - nobody seriously fights them because their deaths impact the wider world around them.

• The death of these beings curses the earth where their body fell.
• Killing them chips away at a more fundamental protection of the world (some worse god or entity eating the world, perhaps?).
• Each one collects the souls of his victims in a little internal organ that destroys the souls if it's ruptured or crushed, and the only way to save the souls of his victims is to capture him and perform a delicate procedure to free them. His enemies refuse to outright kill him on the battlefield because it would mean the damnation of his hundreds of victims.
• They're the gut flora of the world. Perhaps they emit some kind of spore or something that the world needs in order to survive. The forests would die, the crops would rot on the vine, or the air would become putrid.

Answer 4

Resources

Your race of immortals still needs to eat/drink and maintain a certain level of technology.

No matter how far advanced the biology of your mortals it would be difficult to alleviate the need for food and water. This constraint is often cited as one of the features needed to differentiate living and non-living phenomena.

Human beings are highly dependent on technology. We digest our food by using fire, possibly allowing for a larger brain as we do not need support a more costly digestive track. Alternately historical records indicate societies with longer lifespans secure things like oil from lower lifespan societes (examples the first and second gulf war, Nazi agression towards the, I believe, the Caucuses).

Further, longer lived races would be better off hoarding. If you need aspirin now, you would be better off buying bulk quantities as this would suggest a need in the future. This would become even more of a problem if there is a known limited amount of aspirin (which there isn't, but you get the point).

Answer 5

They're like people. They don't generally act rationally, consider the long-term consequences of their actions, or worry about the distant future, especially if there are more immediate concerns. In short, engaging in war to our long-term detriment isn't something you need to explain, so much as it's a fact of life (as we know it).

Most of what you've said about this race could be said about humans. Consider:

long-lived-but-slow-at-reproducing race

Humans are both long-lived and slow at reproducing, compared to other life on this planet, both historically and in modern times. Historically, we had slow growth rates due to factors like high infant and childhood fatality rates; in modern times, the reasons are more economic, but either way, we reproduce much more slowly than most other other species, even other mammals. Consider that medical technology in modern times has given the human population the highest growth in history, at ~2.1% per year. That's pretty slow, and historically it's been well less than 1% per year.

We are also one of the longer-lived species (of animal life) on the planet and are an extreme outlier when you consider our physical size and metabolism. (Lifespans generally increase with increasing both body size and lower metabolic rates.)

Why would a long lived race decide to wage war and fight others, knowing that (regardless of the outcome) they will be losing many more people than they will be able to give birth to in a long time?

That description seems like it fits the human experience with war, too. Big, modern wars like WWI and WII are self-evident examples but even older wars set back population growth, economies, progress and so on by generations too. Casualties might have been lower in the past, but there were fewer people too, and the disease caused by the large grouping of people into armies historically killed more people than actual combat.

When you get right down to it, the difference between your fantasy race and people is smaller than the similarities, and I think your focus on that difference makes you miss the similarities.

Your question makes an implicit assumption here that people actually consider such things before going to war (or are generally rational, for that matter), but the evidence we have from examining our own past indicates that neither of these things are actually true.

If you dig into the politics and power dynamics it gets stickier, but makes an even stronger case against those assumptions. The people in power, the people declaring the wars are self-interested (like all people), and the long-term good of the species or society or whoever is much less important than whether the war is in the self-interest (or perceived self-interest) of the people making the decisions.

So, why would a long-lived race be aggressive and warlike, despite the dangers and self-detriment? For the very same reasons that the long-lived species we call "human" is aggressive and warlike, despite the dangers and self-detriment. :)

Answer 6

These immortals have some advantages to these wars:

Practice practice practice. When you have thousands of years to hone a skill, you get extremely good at it. With a bow, by year one or two (a blink of an eye to them) they will be proficient. By year 5 they will be experts. By year 10 they can start to challenge today's Olympic-grade archers. By year 20 they will be the best Earth has to offer. By year 100 they will be banking arrows off surrounding terrain and impaling 3 enemies with a single arrow...and then it's time to learn to ride a horse. Infinite life spans allow for a level of training humans today can't really perceive...by the time they've had 500 years of horseback archery practice, then they can get to training melee weapons.

Equipment. A similar line of thought above, when your master armourer has several millennia to perfect his craft before a single piece of equipment they create is actually used, you can guarantee the equipment they make is beyond what a mortal could consider.

Guerrilla. I actually dislike the image of the traditional 'elven' army...you have troops that make Earths Mongol horde look new to horseback riding and bow use that make WWII era rifles seem ineffective...why engage in a classical battle when you could be harassing their formations long before the battle starts. Hit their troops as they march to war, as they camp, and as they try to supply themselves. In a hit-and-run sense (do the damage and get out before you take losses), these elves would win wars before the main battle is engaged.

Remember time can become a weapon to these immortals as well...they don't have to take risky moves that sacrifice lives to save time. They can engage in tactics that draw out conflicts and strain the oppositions resources (money, lives, food, and everything else needed in war). A particularly strong enemy king won't be around in 50 years, why destroy what time will take down for you?

With all that said: I want to know what good reasons this race would have to enter a war or generally have high "fightiness"

1) As prefaced - their training, armour, and tactics can all be adapted to greatly limit the number losses they take...they may not view war as the high casualty event that other races see it as.

2) Immortals still need resources. Lacking resources you need still remains the number one reason for war.

3) Boredom. If you're training for millennia, you are going to want to put your skills to use. War becomes sport and entertainment and glory.

4) Power. If you're going to live for millennia, you may want to leave your imprint on this world over an extended time frame...seize power and shape the world to what you want it to be.

Answer 7

The god that created them expected to create more.

The way you describe these beings, they pretty much will live forever, except for the case where they are outright killed, or die from starvation or thirst.

Death from starvation or thirst is a problem with its roots in limited resources in their world.

If you only add (and never remove) individuals, assuming that each individual requires roughly the same amount of resources (specifically in this case, food and water) to live, then resource usage grows linearly with number of individuals. However, a world can only provide so much resources, so at some point starvation becomes a real issue.

Dying from starvation is not exactly pleasant. Dying from thirst is perhaps even worse.

Since the god expected to create more of these beings, the god planned the beings with population-control measures built in. One obvious such measure is to have your beings fight each other to the point that one, or both, will no longer be a drain on resources. This can be coupled with any way you prefer of making it more palatable, including the lofty concept of "honor".

This doesn't need to involve all-out fighting in an "everyone against everyone" style; only sufficient to compensate for the rate at which the god expected to create more of these beings. If it takes a long time to create one, then the rate of fighting will be low; if it's a trivial task, then the rate of fighting will be high. Adjust to taste.

Besides, it makes for great fun to watch. Just ask the old Romans. Your god might, too, have enjoyed watching the battles.

Answer 8

What if the god you talk about needs sacrifices to summon them? They only appear to create more beings when x amount of blood has been spilt. So to avoid extinction by the occasional accident or starvation, they have to fight to bring their god back. If they are good at it, they will grow the population every time they bring the god back, if they are bad they will head towards extinction faster.

There could also be other incentives for bringing the god back. Like maybe everyone who dies only goes to the after life if the god comes back to take them there. So Tom trips and falls off a cliff, now his entire people go to war to to bring the god back so Tom can go to heaven. It's a silly example, but hopefully you get the idea.

Answer 9

First off, understand that it is likely that you will underplay the brutality of war in the process of trying to create a race which intentionally engages in war. Whatever you create will ring hollow, because the war you create must not be as bad as war truly is.

With that in mind, I would recommend using the view of life as a drama or a play as the basis for this species. You can draw content from the Hindu belief system, for they view life in such a way, though you may have to contort it to create the warlike nature you seek. (disclaimer: in this answer, I am drawing on a religion that I do not profess to, and have not deeply studied. Seek guidance if you want to learn about the actual religion and its beliefs)

In this sense, the members of this race seek to lose themselves in the play of life itself around them. They know that all the folly of the lower-lifespan species around them is just folly, but they want to forget. They want to be gripped by the excitement of the actors, until they're on the edge of their seats. They want to get so involved that they lose track of where they are and what they are. In the Hindu belief system this process occurs over the course of roughly 4 million years. Near the end of the cyclical play, the kali yuga period occurs, roughly 400 thousand years long: a period of strife.

Your immortal race may find that, as they approach this age, all methods they have found to lose themselves in the great play have rung hollow. The only aspects which seem truly immersive are those of war. As long as your race is engaging in war, they feel alive. If they stop, they soon begin to see that the play is just a play, which would be quite undesirable.

The Hindu cycle is 4 million years. If you stretched that out to billions of years, watching stars born and die, I think you could imagine quite a brutal warlike race, suffering like this for billions of years. But the rational for doing so is pure psychology: the desire to get lost in the play of life. So you can choose to make it as religious or as scientific as you please.

Answer 10

Among each other, they don't fight wars to the death.

They are a long lived race that views the lives of their own as sacred, but they still have long-standing arguments that can be remembered for centuries. Though they fight among each other in an attempt to trade territory or seek payment for transgressions, their fights among each other are not intended to be fatal, but they pride themselves in bringing each other close, but not to, death.

As mortals die more easily, the immortals are unintentionally more lethal

They end up very skilled in combat because of the above, but they know that shorter lived races that show any capacity for intellect do fight to the death in war. Additionally, mortal races likely know that these immortals have had millennia to master fighting, so they fight to the death at all costs if forced to fight. The immortals don't try to fight to the death, but the tenacity of the mortals and the lethality of the immortals causes issues.

They see mortals as dangerous in hordes

This forces any wars with the mortals to be extremely dangerous, as they throw thousands against single immortals when possible. The immortals may seek to keep the numbers of mortals down due to this problem, leading them to 'pre-emptive' warfare.

Their society thus promotes battle skill

With the way they fight among their own battle skills are highly valued and paramount. Bring the enemy close to death, but not to to force them to concede victory.

Against mortals, this forces the mortals to be compliant or especially aggressive. It isn't that they chase a defensive war. The issue of how they fight with each other changes their lethality to others.

Answer 11

A few reasons that others have not touched upon or were touched on tangentially:

1. Literal Bloodthirst

Like vampires, they require the large-scale replenishment of external blood and can absorb it via shed blood. Battles and war are the obvious solution, though some will commit mass murder. Without mortal blood, they sink into a torpor that can drive them insane from boredom.

2. Divine Worship

Mortals consider them virtual gods since they have ruled from the ancient days, eternal Pharoah style. Each immortal leads a city, and these cities go to war on a frequent basis as the warlike immortals compete for glory or gold or simple points in a 'game' that has lasted millenia.

3. There can only be One

Yes, Highlander style. The last remaining immortal will gain a wish or become a new god. This has been decreed by divine power.

Answer 12

Here is an answer I didn't see in any other posts:

1) Anti-natalism (It is immoral to have children).

Your race believes it is immoral to have children. Unless your world is an utopian one, bringing a new consciousness into the world risks new pain and suffering. Non-existence is better than risking increasing the suffering in the world, and so races that reproduce must be culled or subjugated to prevent future births. Since members of your race cannot choose to reproduce, they feel uniquely qualified to right this universal wrong, often through war.

Edit:

Since is it possible for a reproducing creature to have infinite descendants, even a small probability of a life of suffering for each descendant sums to much greater suffering than the suffering of one creature. Therefore it is the lesser of two evils to end the creatures life before they reproduce. At the very least invade their lands and sterilize them.

Reference to this idea here: Anti-natalaism

Answer 13

They don't think about death as an end.

They were created by a god or god-like figure. They were not born to begin with and they do not age.They take life for granted, and for good reason too. Their purpose in life is what their god created them for. Whether it is for a crusade, or simply to stir up trouble. Whatever the reasons the god has need not be known, unless your god has proclaimed them to the world.

Death is not something to be mourned in you warrior race. It is celebrated as those who died have achieved their goal in life and returned to their god. Not only do they not age, but they are also strong. Each of your surviving warriors has an uncanny ability to grasp the military and martial arts, and for one to die someone must have really wanted them dead.

That is to say that when one warrior dies, those who've witnessed learn from it and become harder to kill, and possibly spread the new knowledge to other survivors.

With such a trait it is possible that your warrior race covets a death which is witnessed by their fellow warriors to strengthen the entire race, and dying alone is the most shameful death.

Your warriors fight because its what they were created for. They often try to challenge those who are on top simply for the opportunity to become stronger in death.

As a consequence though I would also be inclined to make this race not interested in fighting the weak. They are feared because of their aggressiveness and uncanny skill, but they do not desire a death which nothing will be learned from, and every battle has its risks. They are fully aware that eventually they will disappear. There was never a promise for more warriors to be created if they were to die.

Answer 14

War = Life

Perhaps the immortal race must transform itself between a cycle of forms to stay immortal, and one of these forms is exceptionally aggressive. This could be an interesting source of friction between the aggressive forms and the rest of the artistic/scientific/leadership/etc. forms. (Somewhat inspired by The Mote in God's Eye by Larry Niven.)

They Taste Good

Maybe the immortal species consider other races as a critical food source. I imagine the rest of us would react violently to humans being farmed, and the immortals would want to preserve their source of nourishment. Consuming warlike tribal humans or orcs may have added a huge amount of aggressive behavior to the immortals. (Loosely inspired by The Book of the Long Sun by Gene Wolfe.)

Hardware Bug

Maybe a biological imperative causes them to be more territorial over time. When they were first created, their creator endowed gave them the potential for war but endowed them with a gland that makes a hormone that keeps them calm, happy, and peaceful. Unfortunately, over time, the creator did not realize these glands would atrophy and gradually make them more warlike. Having lived essentially forever, they are very aggressive.

Self Mutilation

Continuing the hormonal idea... Maybe there was a prior race that posed a threat to their existence. The immortals were too peaceful to fight back, but they also knew about this gland and figured out how to remove/suppress it to save themselves. Unfortunately, this act was permanent, and now they are forever aggressive. How tragic! Uncovering the happy past would turn these immortals from warmongering villains into tragic victims. This would yield a nice plot point to restore the immortals to their prior, peaceful ways.

Temper Tantrums

Another alternative: the immortals, despite having lived a long, long time, are actually just in the infant/child/pupa stage of their lives. They simply do not have the capacity to develop the same morals than the rest of the races. Human children can be prone to intense fits of rage. Combine this with an infinite amount of knowledge and power. Frightening!

Morals

Speaking of morals, I have no idea what the moral code of an immortal race would be. Over millions of years, I expect many people would have developed way past what we consider to be "right". They might consider it a moral imperative to kill every other sentient race because we are mortal and therefore just animals. As a mortal, I expect that I would find them quite immoral immortals.

Self-Preservation

I think the immortals would see the mortal races as a clear and present danger. The immortals would likely need to cull the rest of us periodically to prevent resource starvation as we breed without end. Hunting licenses, anyone? 10 bag limits? Or, perhaps they believe that the only answer is extinction for the rest of us, and they will stop at nothing to achieve it.

Personally, I would be terrified if there was a sentient species that could breed a new generation every week and competed with humanity for the same resources. To them, we would be the immortals. How would we react to essentially being overrun? Would killing these critters be justifiable as self-preservation?

Answer 15

Long memories

"That valley was ours five thousand years ago. I remember well the day the humans drove us out. Preparations took a while, but now we are ready. WE WILL TAKE IT BACK!"

"That mountain over there was ours too. My friend Whatstheirname has told me about how the dwarfs stole it ten thousand years ago. WE WILL TAKE IT BACK!"

Answer 16

What would the Krogan do?

Your proposed race sounds very similar to the Krogan from the Mass Effect series of games. The Krogan are extremely aggressive, warlike and hard to kill (regenerating), with their race suffering from "the Genophage" which reduces their reproductive rate.

There doesn't have to be just one reason for your long-lived rowdies to start wars, their situation lends itself to several motives:

1. The Mercenaries and Criminals - you are a near-immortal thug with nothing else to live for. Why not get paid for doing what you enjoy and are really good at (after hundreds of years of practice) - killing the squishy races!

2. The Cure Seekers - your race may be individually tough but the fast breeders will overwhelm you with numbers if you don't come up with a cure for your god's apparent loss of power. The populations of the fast-breeders have increased over the last few hundred years and your god is no longer in evidence. Your theory is that the strength of a god relative to the other gods is proportional to the number of followers. In order to get your god back in the game you and your followers need to reduce the population of the other races. A lot.

3. The Security Dictatorship - the only way to protect yourself and (some) of your race is to climb to the top of the pile and keep yourself there. You read the local equivalents of The Art of War and The Prince over a hundred years ago and have been planning your campaign to take control of the continent since, including rabble rousing and promoting aggressive behaviour among your own people. The time to launch your campaign is now. (This is more inspired by the Shaa from the Dread Empire's Fall series of novels by Walter John Williams than the Krogan.)

Finally, there is the entire concept of risk-taking. Humans learn, as they mature, how dangerous certain activities are. These activities include engaging in combat - as the saying goes, there are bold soldiers and there are old soldiers, but no bold, old soldiers. If you are almost unkillable, your assessment of what activities are unacceptably risky will be very different to those of a human. There will be lots of bold, old soldiers with combat abilities that have increased, not diminished, compared to their youth.

Answer 17

Yawn...

Life is long, mundane, and largely very boring. What else is there to do except gamble your immortality on adventure and conquest?

A Greater Power

There are things in this world, Horatio, far more important than your life or mine. We were put in this world to _____________ and we must not fail. Even if we must throw our bodies on the pyre of righteousness, we must do it!

Ethical Priorities

It comes down to what's important and why. We children of the Darwinian age posit survival of the species above all else. If there's an attractive after-life and no disincentive to rush to it, I'd be surprised if a long-natural-lived species didn't speed up their own destruction.

Answer 18

Their creator made them aggressive. Too aggressive. Their original purpose was to be enforcers, soldiers, warriors. Perhaps the leadership for lesser armies as well (Think of a tribe of goblins in D&D led by a single hobgoblin). They are strong and tough. They heal quickly. The tire slowly. They don't die easily.

Early on, the god would simply make more of them after each battle. Perhaps the god would resurrect the fallen as well.

Now? The god is silent. No one knows why the creator no longer takes an active hand in their battles, and some of the greatest warriors in memory number among the fallen.

Thus, their ultimate destiny is extinction. However, that is the future, and this story is in the present.

Answer 19

They are arrogant.

Members of an immortal race individually hand-crafted by a god (so to speak... you mentioned each were manually created) probably have a pretty high opinion of themselves. Combine that with the superior equipment and skills that other answers have mentioned and you have a people that probably view other races as savages at best. They may view even the slightest perceived insult as a provocation. War could be viewed as a way to "teach those vermin their place".

Answer 20

Honor

Some things are more important than survival, and chief among these is honor. If someone insults your 10,000 year-old ancestral name, encroaches upon your ancient lands, or speaks ill of your creator, it cannot be allowed to stand. You did not seek this fight, but you will pursue it with grim determination, and show the world that you will tolerate no disrespect.

Your race wasn't created to merely survive. They were created to be a great power in the world, which means a willingness to pick up arms and fight when duty calls. Better to burn bright for a while than to burn dimly forever.

Answer 21

Natural selection. Of a kind.

Over the ages these immortals where generated by their god.

Some of them shyed from conflict. Others embraced it. Others where neutral.

The conflict-scared and neutral where wiped out century after century. Those that survived formed empires and led their peons against other immortals and against free peoples.

Most of those that failed to form empires where killed and enslaved by other immortals and free people's.

Those that live are those that lived. Violence is only against survival when the alternative isn't worse. War is worse for non-combatants than it is for soldiers.

There will be some immortals that are peaceful and hate war, but they are far outnumbered. Of them, the vast majority are immortals that have been broken and enslaved by free peoples or other immortals. A minority of a minority are the peace-loving immortals that remain free and indepenent.

With the end of new immortals, the dynamics have changed a bit. But immortals are also creatures of habit, and adjusting to the new era isn't for everyone.

Answer 22

Make them extremely religious. They are directly created by a God, so they are in touch with divinity. They are keepers of the righteous belief and the return of the God is directly linked to the "spark of belief".

Then you can introduce a "satanic" group that they battle, or if other intelligent species exist (like normal people) they can fight the decadent inferior competitors. Or the "humans" rebel and do not help them maintain the belief in the God and they need to fight to crush the rebellions. You created a very interesting introduction with a direct manifestation of divinity. Why not use it to motivate them?

That way you can link the very creation of new ones to their need to fight now (they need to keep the religious belief in their God so he will return and make more). The future reward justifies the sacrifices now.

Answer 23

The standout reason for me that species may be war-focused and violent is that their species has become zealously defensive of their longevity. All it would take is one charismatic member of their species to spread propaganda that all other species would take the ability if they could, and in only a couple of generations' time, extermination of other species' would become a normalised behaviour, global effort, or simply tradition. Perhaps if an attribute of their being grants them their long life, other species may have hunted them in the past to gain it, or at least, stories of such may be circulated to encourage their defense.

Tl;dr - overzealous, almost religious defensiveness, used to validate violence and holocaustic extermination.

Answer 24

The best defense is a good offense. They could view all mortal races as warlike children who cannot be peacefully coexisted with. War would be inevitable. the only question would be the timing. The immortals' chances of victory are much greater if they attack mortal enemies by surprise and when those mortals are fewest in number. Most populations of intelligent creatures tend to grow over time, so the logical move is to wipe them out immediately.

A tribe or nation of mortals might respect the immortal race and live in peaceful harmony. But it is is the nature of mortal people to change over time. Eventually, those mortals will experience a period of violent expansionism. It makes no sense for the immortals to wait for that to happen.

This would work well unless you intend for this immortal race to also be mindlessly aggressive toward other immortal races. Though, it would only take a grudge in that case to justify perpetual hatred and mistrust.

Answer 25

There are the classics like money, resources, land, slaves,...

However, they could wage war against another nation of weaker beings but who reproduce very easily (a race that relies on swarm tactics). If your "immortal" race wants to avoid being outnumbered by this potential enemy, they could wage war to try to make this swarming race extinct, especially if there are hostilities (like some sort of cold war).

Answer 26

One potential answer is in your question.

If they don't fight the mortal races to cull their numbers, they will be outnumbered and outpowered under the mortal swarm. And they know from experience that being outnumbered by an intelligent species is not to their benefit in the long term.

Answer 27

well, the most obvious reason is "because more would die/suffer if they don't"

So if you can reason that the enemy wants to kill all of your race, then war doesn't seem so bad an alternative.

And they might not put survival as their topmost value - i.e. people die all the time for imaginary gods or similar values - why should be people who live longer be excluded from such things?

Answer 28

Entertainment

Their longevity allows them to hone their craft, more so than other races. It isn't far off to consider most of their race could be masters at the art of combat they so choose. And with longevity, can come the blandness of everyday routine. Practising combat everyday, watering the garden, eating.. all of it becomes a chore once you do it hundred years or so. Perhaps your race is fight-y because it adds that bit of spice to their lives. Combat is rarely the same each time, perhaps they seek a the cliche'd worthy opponent amongst the rest of the lesser lived races.

Culture/Status

Perhaps their kind's culture revolves around combat. One's status is heightened depending on how many other esteemed warriors you've felled/defeated. It isn't a required feat among them, being combat ready is already a good quality to have but to rise higher, one must prove their mettle. This may be similar to most Orc-y races.

Self-Imposed Authority

They could, say, see themselves as the higher race among the rest and come to blows with other races simply because of their beliefs. I would go to say that they're protectors of the earth, ridding the world of pests. Take the elves from Lorwyn/Shadowmoor of Magic: the Gathering. They believe themselves the better, beautiful race and in this light purge the rest of the races which they call eyeblights.

Answer 29

To be the last one standing/A whole lotta power

Eventually the god will come back to check on them and create more (otherwise they'd die off given a long enough time frame no matter what). When the god does come back to create more, whatever tribe or individual is left standing will be the de facto ruler of the new members and will become immensely powerful, regardless of any favours or gifts given to them by the god.

Answer 30

We mostly meet warriors.

Or at least former warriors. Whatever they do after a few hundred years it's time to move on to something else, but whatever else they do having been a warrior leaves a lasting impression. She may look like a fishmonger now, but she learned that knifework with a sword.

They could have a general draft, or consider war a part of a well rounded education to further enforce this. When you are good at fighting it always seems like a solution to the current problem. It might even turn out to be the best long term solution if word gets around that they are good enough at it.

People who have not trained to fight often find people who have unexpectedly aggressive, because they either skip the normal preliminaries of intimidation or successfully use intimidation, winning the fight without fighting.

Conversely if one of these people wants to live a quiet life they would probably get pretty good at that too, and no one would ever hear about it.