The 20-Year Entropy Standard

Parameter Tuning Methodology

The simulation no longer asks: “Can the empire survive?” It now asks: “How does the empire die?”

The default state of the simulation is COLLAPSE. Stability is a temporary deviation, not the norm. We model a 20-year timeline (1040 ticks) because that is sufficient to observe the systematic decay of any imperial system operating under capitalist extraction.

The Problem: Eden Mode

Previous specifications permitted infinite stability because:

Existence was free: base_subsistence = 0.0 meant entities persisted without cost
Earth was infinite: No hysteresis in biocapacity degradation
Zombies were possible: Entities survived with near-zero wealth indefinitely

This produced “flatline” simulations where nothing happened.

The Solution: Dying World Physics

Under the new standard:

Existence costs calories: base_subsistence > 0.0 always (The Calorie Check)
Death is real: VitalitySystem kills entities when wealth < consumption_needs

The 20-Year Benchmark

Old Standard	New Standard
52 ticks (1 year)	1040 ticks (20 years)

Why 20 years?

Long enough to observe TRPF (Tendency of the Rate of Profit to Fall)
Long enough for ecological degradation to compound
Long enough for generational effects
Short enough for meaningful simulation runs (~10-20 minutes)

Success Criteria

OLD: “Success = Survival”

NEW: “Success = Realistic Decay”

The ideal simulation produces:

p_c_wealth declining ~0.05% per tick
total_biocapacity declining ~0.08% per tick
imperial_rent_pool exhibiting TRPF (declining rate of return)
Death occurring in the 800-900 tick range (Year 15-17)

The Calorie Check

INVARIANT: base_subsistence > 0.0 in ALL scenarios

This is the foundational constraint that prevents Eden Mode.

# FORBIDDEN - Creates Zombie States
defines.economy.base_subsistence = 0.0  # NEVER

# REQUIRED - Ensures Entropy
defines.economy.base_subsistence >= 0.01  # ALWAYS

Every scenario factory and test fixture MUST verify:

def create_scenario():
    defines = GameDefines()
    assert defines.economy.base_subsistence > 0.0, \
        "Eden Mode detected: base_subsistence must be > 0.0"
    return state, config, defines

Objective Function

The optimization objective rewards realistic decay:

def objective_v2(trial):
    """Optimize for REALISTIC DECAY, not survival."""
    result = run_simulation(trial.params, max_ticks=1040)

    # Death Timing (40%): Should occur around tick 850
    death_tick = result.death_tick or 1040
    timing_score = 1.0 - abs(death_tick - 850) / 400

    # Decay Shape (30%): Smooth decline, not flatline or cliff
    decay_smoothness = calculate_curve_smoothness(result.wealth_timeseries)

    # TRPF Manifestation (20%): Rate of profit declines
    trpf_score = calculate_declining_rate(result.rent_pool_timeseries)

    # Biocapacity Exhaustion (10%): Near-zero around death
    exhaustion_score = 1.0 - (result.final_biocapacity / result.initial_biocapacity)

    return (0.4 * timing_score +
            0.3 * decay_smoothness +
            0.2 * trpf_score +
            0.1 * exhaustion_score)

Anti-Patterns

Zombie State (Flatline)

Symptom: Wealth graph is horizontal
Cause: base_subsistence = 0.0 or consumption_needs too low
Detection: std(wealth_timeseries) < 0.01
Fix: Increase consumption_needs, verify Calorie Check

Instant Death (Cliff)

Symptom: Simulation ends before tick 100
Cause: Extraction too aggressive, initial wealth too low
Detection: death_tick < 100
Fix: Reduce extraction_efficiency, increase initial wealth

Eternal Empire (Eden Mode)

Symptom: Survives 1040 ticks without significant decay
Cause: Extraction perfectly balanced with production
Detection: wealth[tick_1000] / wealth[tick_0] > 0.9
Fix: Enable biocapacity hysteresis, increase entropy_factor

Hollow Stability

Symptom: Metrics oscillate around stable point
Cause: System finds equilibrium (theoretically impossible)
Detection: mean(wealth[500:1000]) ≈ mean(wealth[0:500])
Fix: Increase TRPF coefficient, add extraction hysteresis

Parameter Ranges

Entropy Parameters

Parameter	Range	Purpose
`economy.base_subsistence`	[0.01, 0.05]	Calorie drain per tick
`metabolism.entropy_factor`	[1.1, 1.5]	Extraction inefficiency

TRPF Parameters

Parameter	Range	Purpose
`economy.trpf_coefficient`	[0.0001, 0.001]	Rate of profit decay
`economy.rent_pool_decay`	[0.001, 0.005]	Background rent evaporation

Workflow

Verify Calorie Check:

poetry run python -c "
from babylon.config.defines import GameDefines
d = GameDefines()
assert d.economy.base_subsistence > 0.0
print('Calorie Check: PASSED')"

Run 20-Year Simulation:
```
mise run sim:trace --ticks 1040
```
Verify Decay Curve:

Review the generated CSV for realistic decay patterns.