Managing Herd Size
Animals breed on their own, and left unchecked they'll eat you out of house and home.
- Prototype complexity
- Who plays
- Solo decisions
- Design focus
- Planning · Economy · Optimization
No.129RimWorld01The core loop
Action → feedback → next choice- 01Watch the population grow
- 02Gauge resource pressure
- 03Limit, sell or cull
- 04Hold a stable size
↻Feedback changes the situation — the next round starts from there.
Walk through one round
A simplified design example. Situations and numbers illustrate the mechanic, not exact rules from a reference game.
- T1
Turn 1 · The situation
The ranch holds 12 rabbits eating 24 feed a day, with 5 days of stock.
- T2
Turn 2 · The player chooses
The player sells 4 males and keeps the 8 best breeders.
- T3
Turn 3 · The feedback
Daily feed drops to 16, stock lasts about 7 days, and income rises by 200 gold.
- T4
Turn 4 · The next decision
The player sets an alert to sell whenever the count tops 10.
How it plays
Herds reproduce at their own pace, and each new member adds food, space and care pressure. Players separate, use contraception, sell or cull to control size. Overgrowth triggers hunger, crowding or illness.
What the player weighs
- Keep more for output vs. cut consumption
- Cull for meat vs. sell or keep breeding potential
02Start small
Scope is an editorial estimate for the minimum prototype, not the reference game or a production schedule.
03One mechanic, different implementations
RimWorld
Tamed animals breed on their own and eat heavily, so players designate slaughter in the animal panel; newer versions add auto-slaughter by population thresholds.
Planet Zoo
Players can apply contraception or release surplus animals to the exchange, and overcrowded habitats reduce welfare.
The difference worth noticing
In RimWorld herd control is about colony food survival; in Planet Zoo it's about welfare and business efficiency.
Case notes are Yoroll editorial summaries; rules may change between versions.
04What could you combine?
Combine with sensor control: pen counters auto-close breeding gates or route animals to another belt when the count exceeds a threshold.
Prototype this combo in Yoroll→Follow the next idea
Habitat Capacity Check
Before adding an animal, check whether the space can take one more.
- Prototype complexity
- Who plays
- Solo decisions
- 01Check habitat needs
- 02Plan space and features
- 03Add an animal
- 04Monitor welfare
Who Can Live Together
Some species coexist peacefully; others fight or eat each other.
- Prototype complexity
- Who plays
- Solo decisions
- 01Check species traits
- 02Design a mix
- 03Introduce and observe
- 04Adjust or separate
Drone Logistics Network
No belts needed: flying units deliver where needed, but you have to keep them supplied.
- Prototype complexity
- Who plays
- Solo decisions
- 01Build ports and storage
- 02Set requests and supplies
- 03Drones deliver automatically
- 04Expand or refuel the network