v0.31:Immigration

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

v50.14 · v0.47 · v0.34 · v0.31.25 · v0.28 · v0.23 This article is about an older version of DF. More Info · V

Immigration can occur at any time once per season. Smaller migrant waves of 2 to 10 seem typical in early seasons, followed by a large wave in the low double digits in the second Spring, one year after embark. It may be the case that the first 2 migrant waves are special and possibly generated out of thin air, like all waves used to be. Even if your parent civilization is extinct, two waves will still show up. Each group of migrants will often include domestic animals, either as a pet or unclaimed livestock. Be prepared with adequate Template:L, Template:L, and Template:Ls, among other things. Max wave size reported to date is 28.

Migrants will 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

Labor preference bug

Each migrant can arrive with a wide collection of often unrelated skills, far greater than possible with one of the Template:L, and Template:L levels as high as Legendary. Any and all skills might be represented, including obscure military skills (like Template:L), high levels of one or more Template:Ls, Template:L, Template:L and others. It's even possible to have dwarves with skills that may not be obtainable by other means, like Template:L.

Immigrants may have high skills in certain Template:L without actually having them enabled in their labor preferences. This leads to dwarves either doing jobs from an area they are not labeled for or no work at all. For example, an adequate cheese maker (with the cheese making labor turned on) may also have the skill bone carving on "high master", albeit turned off in his preferences. The dwarf in question is listed as a bone carver on screen and in the Template:L tab, but will only perform the cheese making labor. Individually checking each immigrant for skills and labor preferences is the only workaround so far. But the use of programs such as Template:L can greatly decrease the time taken to check each dwarf's skills.

Military Immigrants

Any immigrant, with apparently any collection of skills, may also arrive with some Template:Ls, all of the same Template:L level. These appear consistently to be:

• Armor User
• Fighter
• Dodger

...and one of either...

• Wrestler, Striker, Kicker, or Biter

...or...

• 1 (or more*) weapon skill

and

• Shield user

*If more than 1, then the total experience divided between the skills seems to be approximately equal to that of any of the other skills.^[Verify]

Limiting/preventing immigration

Immigration should stop when the fortress population exceeds the POPULATION_CAP option found in Template:L; to stop immigration, set it to a number lower than your current population. However, this option doesn't seem to effect the first few immigration waves, and it might only take effect after the first dwarven Template:L leaves your site. ^[Verify] For some people POPULATION_CAP doesn't work at all. ^Bug:2922 A possible workaround is to edit the Template:Ls so the the Template:L of your fortress is negative, which should scare away new migrants.

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. There won't even be a The fortress attracted no migrants this season message.

Migrant wave sizes

The first two migrant waves have a minimum size of 2 and a maximum size of 9 or 10. The size of these waves is unaffected by fortress wealth.

The third migrant wave and on are influenced by the Template:L 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 Template:L. 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. The dwarven Template:L does not report on fortress wealth, in those circumstances where the liaison makes it out but the caravan doesn't.

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 Template:L (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.