Immigration

xTATTEREDx · +FINE+ · *SUPERIOR* · ≡EXCEPTIONAL≡ · ☼MASTERWORK☼

v50.14 · v0.47.05

This article is about the current version of DF.
Note that some content may still need to be updated.

Immigration can occur at any time, once per season. Smaller migrant waves of 2-10 arrive in the early seasons, followed by a large wave in the low double digits in the second spring, one year after embark (the maximum wave size reported to date is 77 ^archive). Each group of migrants will often include such things as children and domestic animals, including both pets and stray livestock. Be prepared with adequate food, drink, and beds, among other things.

Migrants will often have skills that match your fortress' needs — migrants with skills your fortress uses a lot or skills that your fortress doesn't have at all are more likely to show up at your gates. Important skills (mining, food production, and basic crafting, according to Toady) are weighed more heavily than other skills.^{Source · MP3}

Migration waves are generally a good thing — if you're prepared for them.

Labor preferences

Each migrant can arrive with a wide collection of often unrelated skills, far greater than possible with one of the starting 7 dwarves, and experience levels as high as Legendary. Any and all skills might be represented, including obscure military skills (like blowgunner), high levels of one or more social skills, crutch walker, concentration and others. It's even possible to have dwarves with skills that may not be obtainable in fortress mode like tracking.

Migrants may also arrive with equipment matching their skills. For example, a miner migrant may bring a pick with them. Migrants may arrive with all labors except hauling, cleaning, recovering wounded, and caring for wounded disabled, depending on the settings one has entered into d_init.txt.

Historical migrants

Some immigrants are historical figures. These immigrants come to your fortress with skills representing their history, and may come to your fortress with wounds they have suffered during world generation. Immigrants may even be vampires or werebeasts.

Currently, agents (spies) from your own civilization will retain their assumed identities when they migrate to your fortress.^Bug:10490 This results in immigrants with odd professions like peddler, prophet, and poet that 'override' their automatically-assigned professions. These immigrants are still loyal to your civilization (at least for now) and should behave normally aside from a few minor bugs (like changing names while on a mission^Bug:10928).

Limiting/preventing immigration

In v0.40.05 and above, the d_init.txt POPULATION_CAP setting immediately prevents further immigration once the desired number is achieved, bypassing the two hardcoded migrant waves. There is also a STRICT_POPULATION_CAP setting, which prevents both immigration and babies when reached (although both can be violated by a few special cases, such as the arrival of a monarch). Keep in mind that your population must be at least 80 to get a king and 100 to obtain the current game features.

The number of migrants depends on the created wealth of your fortress and so is affected by your dwarves' activities. Note that if your fortress should ever become a mountainhome, you will receive an additional migration wave with the promotion, regardless of your population cap. The number of migrants is affected by how far below the population cap your fortress is. If your fortress is one dwarf short of the cap, you will receive a single migrant (if any). Also note that population cap will not remove dwarves from an existing fortress but will prevent new ones from immigrating or being born.

It is worth noting that you need a certain minimum population size before any of your dwarves will experience strange moods. Additionally, POPULATION_CAP affects only migration, it has no effect on pregnancies. You will need to alter STRICT_POPULATION_CAP in order to limit births.

To reiterate, the population cap is a (mostly) hard limit on the number of dwarves in your fortress. If you want a fortress with 50 dwarves, simply set the POPULATION_CAP and STRICT_POPULATION_CAP to 50.

Immigration mechanics

The date on which immigrants appear in a season seems to be fixed at the start of that season, but the number of immigrants and their skills are determined when the migrant wave arrives.

There is never a migration in the first winter - literally not even a The fortress attracted no migrants this season message.

Migrant skill levels seem to depend on the size of the home civilization; a difference will be noticed if you picked a dwarven civilization that was not well established (few towns or none) compared to a well established one.

Migrant wave sizes

The first two migrant waves have a minimum size of 1, if a wave member has a relative in your group already, and a maximum size of 10. The size of these waves are unaffected by fortress wealth, danger, or even the extinction of their home civilization. Note that there may be various reasons for a hardcoded migrant wave to not show up, like if it was blocked by a siege or if is not the first fort in the world.^[1]

The third migrant wave and on are influenced by the created wealth of the fortress, with more wealth attracting more immigrants (more research is needed to determine specifics). Specifically, they're influenced by the fortress wealth as reported by the last outgoing dwarven caravan. Wealth created after the caravan leaves has no influence until the next year's caravan leaves. If the caravan fails to make it out then the fortress' wealth is not reported. If the dwarven liason makes it out, but the caravan doesn't, the liaison does not report on fortress wealth.

Imported wealth, caravan sales figures, absolute caravan profit and caravan profit margin either have no effect on migration numbers, or only have an effect by applying a percent modification to the numbers driven by created wealth. If a fortress manages to trade (not offer) away 100% of its created wealth, then no immigrants will come the next season. More research is needed to determine if the aforementioned statistics have any influence on migration numbers.

One factor which is known to affect migrant wave size is the total size of your fortress's units list (all 4 categories), which consists of dwarves, invaders, merchants, and animals which either died or currently live at your fortress. As this number increases, the maximum size of migrant waves will be reduced: starting at a local population of 1000, migrant wave sizes are limited to 10, and at subsequent levels of 1300, 1600, 1800, 2000, 2200, 2400, 2600, 2800, and 2900, the limit is decreased by 1, and once you reach a local population of 3000 you will cease to get migrants at all.

Kurik Amudnil created a DFHack script to prevent the latter from happening, by clearing (and storing, so that it can be restored as wanted) the dead units list of uninteresting creatures. It is available here and is also included in the Lazy Newb Pack.

Adventure mode

In certain locations in adventure mode, you may come across a Migrating Group. One such location is near a recently abandoned fortress; choosing to travel to the group will allow you to talk to the members of your former fortress as they travel back to dwarven civilization.

Fortress Failure Migration

If a fortress is abandoned during unhappy, stark raving mad times the citizens can migrate to your new fortress still stark raving mad (berserk possibly, further looking into required). Likewise, if your fortress happened to have any husks when it was abandoned, some of them may migrate to your new fortress.

Deterring migrants

A different message for migrant arrivals will be triggered depending on your fortress' dangerousness. That number isn't actually a death count, but some sort of composite "fear" value determined by adding up a bunch of sources and dividing them by various amounts. It is not sure exactly what those sources are, but at least one of them is a death count. 0-9 is normal, 10+ is "danger" or "dangerous", and 50+ is "cursed death trap" or "tomb".

Bugs

Also, some migrants will be incorrectly listed as babies or children, when they are not in the expected age range for those categories. This will automatically fix itself when they have their next birthday. Some baby migrants may have future birth dates. ^Bug:3945

If your fortress does not have a meeting hall, you might have a situation where a single migrant can't find the fort and just stands at the edge of the map, not moving at all. You may notice that, even if more migrants are part of the wave, they cannot enter the map (and do not show up on the units screen) until this migrant moves out of the square, as all migrants in a single wave must enter the map through this square.

The Migrant Tier List

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Whenever a migration wave arrives, most players will stop what they are doing to check the migrants' jobs, and determine the migrants' viability in the process. Here, the migrants are sorted into tiers, roughly ordered by usefulness. Do note that even F-tier migrants can be useful if a player decides to make them so, and of course any migrant can be useful as a hauler or soldier.

Valued Migrants (S)

These migrants can improve a fort simply by showing up. Also known as "can I give them a mood please?".

Weaponsmiths: Because who doesn't carry a big stick these days? If you have an excess of weapons you can also use weaponsmiths to make extremely high-value trap components.

Armorsmiths: As useful if not even more useful than weaponsmiths.

Soldiers: Who doesn't need extra ~~meat shields~~ dwarfpower? If you don't have any soldiers yet, you can form your militia, and if your militia is already well-developed they can act as reservists, in case something Fun happens to the militia.

Miners: Always helpful, and a high mining skill can be useful in combat.

Growers: Always useful to improve farm efficiency exponentially. Note that a few skilled Growers are probably better than a dozen unskilled ones.

Cooks: Will quickly boost your fortress's value and dwarves just adore fine meals.

Brewers: Should be obvious. Alcohol doesn't have a quality level, however, but an increase in production speed is never unwelcome.

Engravers: A good engraver can smooth and detail a large room in minutes, shooting its quality sky-high, while a novice might take hours. Novice engravers also take quite a while to train.

Good Migrants (A)

Put these dwarves to work, they have much to contribute. Also known as "stalwarts of the fort".

Blacksmiths: These dwarves make metal (not just iron) furniture and other large products, including valuable metal statues.

Carpenters: Like Blacksmiths, but they use wood instead of metal. They're especially useful for making high-value beds and wooden trap components.

Stonecrafters and Masons: It's always useful to make finished goods and furniture, respectively, out of stone if metal or wood is economic.

Metalcrafters: Do you want to fill the next caravan with *silver mugs* and other metal finished goods? Now you can!

Glassmakers, Potters, and Glazers: Glassmakers can produce many products, including crafts and furniture, out of glass, and said products are often worth much more than their stone counterparts. Potters are less versatile but can also make valuable products for a decent enough price, and pots supersede barrels by weight. Note that Glassmakers require sand, and Potters clay, in large quantities to be truly effective, but these resources are basically infinite on embarks that contain them. Glazers complement Potters and are needed to make said pots airtight and waterproof, and a good glaze job adds a lot of value to a product.

Healthcare dwarves are always useful, for trying to save that one beloved soldier faster.

Mechanics: High quality mechanisms can help your machinery run smoother, and they also make great trade goods.

Leatherworkers: Leather can be used to create certain items that can't be created sensibly with any other material; such items include backpacks, quivers, and lightweight shields and armor. Unless, of course, you're using adamantine.

Herbalists: Herbology is a great way to kick-start an above-ground farm, or at least keep your food supply varied. Even dwarves get sick of drinking the same old mushroom wine.

Strand extractors: Skilled strand extractors are quick, as unskilled strand extraction is agonizingly slow. Only useful after raw adamantine has been discovered and mined, and the strands do not have quality levels.

Average Migrants (B)

These migrants can be useful, but generally add less value to the fort than the above categories. Also known as "it ain't much, but it's honest work".

Gem cutters and Gem setters: They just don't produce as much value as you'd expect, unless the gem cutter is of a high enough skill level. Even then, gems are only useful for moods, decorations, or as a trade good. Training Gem cutters so they don't waste your rough valuable gems is also extremely tedious. As for Gem setters, encrusting is notoriously finicky, since the item to be decorated cannot be specified. So your Gem setter will end up slapping your Masterwork cut diamonds on a barrel or something.

Hunters: They usually come with a good Marksdwarf skill, but immediately go hunting as soon as they're ready, causing uncontrolled dwarves and possibly Fun. They can be useful if handled properly, and are definitely entertaining to watch. It may be advantageous to just rely on your military for hunting game, since squads can be controlled more finely than Hunters.

Fisherdwarfs and Fish cleaners: Fishing is a decent source of food, and it's a great source of the elusive shells if your site contains pond turtles, but it runs the risk of crocodile accidents and other perils. Or, if you're unlucky, you'll get absolutely nothing. Fisherdwarves can also only catch vermin fish, larger sea creatures may require drowning chambers or other tactics.

Furnace operators and Millers: Neither of these labors have quality levels, but the increase in production speed can be highly profitable for the metal and flour industry, respectively.

Peasants: Not quite useless, they're more like blank slates. Peasants can be trained in a moodable skill to control the artifacts your fortress will produce, and they make good haulers or just plain fodder.

Niche Migrants (C)

Only useful in very specific cases. Also known as "free military conscripts".

Beekeepers, Wax workers, and Pressers: Beekeeping is interesting, but it isn't possible on embarks that lack honey bees (bumblebees cannot bee kept). If you do get a beekeeping business going, Wax workers and Pressers become viable as well, since they use the products of beekeeping in their labors; otherwise, they're basically useless.

Siege engineers and Siege operators: Would be useful, but siege engines are currently bugged, dealing much less damage than you'd expect, and are often extremely dangerous to your own citizens when they do work as intended.

Butchers, Gelders, Animal trainers, and Tanners: While these labors can be pivotal to a fort's usage of animals, you really won't need more than one of these dwarves unless your animal or hunting industry is truly booming.

Woodcrafters: Shun the elf sympathizers! Not to be confused with Carpenters, these dwarves make useless crap out of wood, which is so worthless as material you might as well not even bother. You're better off using stone or metal to make finished goods instead.

Bone carvers: Bone is neither valuable (unless the creature was a megabeast or was exceptionally exotic) nor does it fill a particular niche, but it is a rather common alternative to wood.

Dyers: When was the last time you dyed some cloth? Skilled Dyers do add extra value to dyed cloth, as it does have a quality level, but come on.

Bowyers: Bowyers can make crossbows out of wood and bone. That's all. Weaponsmiths can do everything bowyers can do, except better, because heavier metallic crossbows can be used as good blunt weapons in close quarters.

Potash makers, Lye makers, Soapers, Wood burners, Pump operators, Woodcutters, Milkers, Cheesemakers: The products of these labors do not have quality levels, so the only difference between an unskilled laborer and a highly skilled one is production speed, which is really only critical if said products are the backbone of your industry (and who specializes in soapmaking?). At least you'll have another dwarf to add to your soap industry, but you can easily just activate these labors on some random idlers to little to no ill effect. Note that many of these products cannot be sourced from caravans, which makes in-house production a necessity.

Bookbinders, Papermakers, Weavers, Shearers, Threshers, and Clothiers: It's so much easier to just obtain codexes, paper, cloth, and clothes from the caravan and migrants instead of producing them yourself, as these industries are often needlessly tedious or require a ton of setup.

Completely Useless Migrants (F)

Also known as "can I toss them in the volcano please?"

Animal dissectors and Fish dissectors: They make animal extracts, which are some of the most useless items in the game.

Trappers: These dwarves make animal traps, not cages, which can only be used to trap vermin, not large creatures. They do tend to come with the Marksdwarf or Animal trainer skill, so their true value may lie elsewhere.

Animal caretakers: Bugged at the moment and may become more useful when the bug is fixed.

Children: Cannot perform any labors whatsoever. At least you'll have a Peasant. In about 12 years.

Other

Pilgrims, Peddlers, Prophets, Poets, Monks, Criminals, and others: These individuals are agents from your home civilization under a false identity, and are usually benign. Determining their usefulness may require closer inspection of their skills, and killing them will reveal who they truly are.

Monarchs and Outpost liaisons: Serving as a major endgame goal, inviting these members of dwarven society comes with its own requirements and caveats, requiring a large amount of investment, labor, and time. The player can choose to never pursue this goal if they wish.