Produce no wealth and live in a dirthole with no rich crafts.
Other than the death counter, its created wealth that drives immigration. IIRC, its "created wealth as reported by the caravan" So not letting the caravan leave (yet alone arrive) can also block the news. If you notice, the first "big" wave will typically be the wave right after the caravan. You go from the standard small waves to "holy hell I made too many dwarven syrup roasts!" wave.
I believe there is also the local unit list bug. If your sum total of units (including dead) reaches 3000, you'll gain no migrants. I believe there is a cut off of reduced migrant waves over 1000 local units. There should be a DFHack script to clear out/restore the dead units as well.
What I am getting at, is that you can keep wealth to an absolute minimum (no engravings, make only what is essential) and bring a ton of fast-breeding animals on embark. Then, either slaughter or just atom-smash/pit into lava most of them until you hit 1000 units on the local pop screen. You could also routinely kill off all your tavern visitors. From past reports, they just refill faster and faster as you kill off the existing guests. Turkeys come to mind. The poults only produce a skull when butchered, iirc, so it won't flood your fortress in products either. Also, probably turn everyone into hunters/military and just slaughter everything that wander onto the map. If an animal arrives/leaves, it'll be cleared from that local list. If it dies in your fortress, it'll clog up said list. You can live-train your military on large (10+) crundle packs while doing this. Just don't use axes or even swords... the severed limbs count as separate butchering jobs. I tried to live-train some axelords in the caverns before... completely overwhelmed my butchers with all the "spare parts" created. I wound up with 3 of them to process crundle arms and heads.
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Topic: Immigration rate-limiting (Read 730 times)