The Rules tab defines how organisms interact with each other and with their environment. Two sections cover predation constraints and the five behavioral force multipliers that drive each organism’s decision-making every tick.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/jkh2/Primordial-Sim/llms.txt
Use this file to discover all available pages before exploring further.
Predation settings
| Setting | Type | Default | Description |
|---|---|---|---|
| Same Species Protected | Checkbox | On | When enabled, organisms cannot eat members of their own species regardless of size difference. |
| Food Chain (Rock-Paper-Scissors) | Checkbox | Off | Restricts predation to a cyclic chain: species 0 eats species 1, species 1 eats species 2, and so on, wrapping so the last species eats species 0. |
| Size Advantage to Eat | 1.05 – 2.0 (step 0.05) | 1.3× | Minimum size ratio required for an organism to eat another. At 1.3, a predator must be at least 30% larger than its prey. |
| Energy from Eating | 0.1 – 1.0 (step 0.05) | 0.50 | Multiplier applied to prey size on a kill: the predator gains prey.size × eatGain energy. At 0.5, eating an organism of size 10 gives 5 energy. At 1.0 it gives 10 energy. |
Same-species protection
When Same Species Protected is checked (the default), the predation check short-circuits for two organisms of the same species — even if the size ratio condition would otherwise be satisfied. This encourages intra-species flocking and gives smaller individuals a survival buffer.Food chain (Rock-Paper-Scissors) mode
When Food Chain is enabled the simulator usescanEatInChain logic instead of the default open-predation check. Each species index s can only eat species (s + 1) % numSpecies. This creates a cyclic dependency where no species can dominate all others simultaneously, producing oscillating population cycles similar to a three-species Lotka–Volterra system.
Food Chain mode is most effective with 3 or more species. With 2 species it degenerates to a one-directional predator–prey pair.
Behavioral force sliders
| Setting | Range | Default | Description |
|---|---|---|---|
| Hunt Drive | 0 – 3 (step 0.1) | 0.8 | Strength of the steering force that moves an organism toward edible prey within perception range. |
| Flee Drive | 0 – 4 (step 0.1) | 1.5 | Strength of the steering force that moves an organism away from predators within perception range. |
| Flock Cohesion | 0 – 2 (step 0.05) | 0.4 | How strongly same-species organisms cluster together. Higher values produce tight schooling behavior. |
| Food Attraction | 0 – 3 (step 0.1) | 1.2 | How strongly organisms seek out food pellets. Competes with hunt and flee drives for influence over movement direction. |
| Separation Force | 0 – 2 (step 0.05) | 0.6 | How strongly overlapping organisms push apart. Prevents pile-ups and ensures spatial distribution. |
Setting Flee Drive significantly higher than Hunt Drive (for example, Flee at 2.5, Hunt at 0.4) shifts the ecosystem toward a prey-driven dynamic: prey scatter effectively, predators rarely catch them, and food attraction becomes the dominant survival strategy. The reverse — high Hunt, low Flee — creates efficient predator-led culling.