Rules & Behavior

Configure predation mechanics and behavioral drive strengths.

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.

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 uses canEatInChain 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.

Each frame, the net velocity for an organism is computed by summing all active force vectors (hunt, flee, flock, food, separation), each weighted by its respective slider value, then clamped to the organism’s speed gene.

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.